Richard's Simplicity road roller first appeared in public at NSME Bits and Pieces Night in April 2019, where Richard was awarded the Bassett-Lowke Bowl, and later presented with a trophy to keep. Progress since with the roller is recorded here and updated as it happens.

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Two pictures of the reversing arm for the 3" scale Simplicity road roller. You may find it interesting that it is machined from solid, a piece of 2" diameter steel, rather than fabricated, which is the more usual method of manufacture - judging from models seen. Richard is currently erecting the hornplates.

February 7, 2020.

The pictures include the erection of the hornplate for the roller and trial fitting of brake gear, stub axle assemblies and differential/final drive shaft and bearings. Next stage is machining the boiler mounting plates.

February 11, 2020.

One photo shows the boiler mounting plates being machined to a nice snug fit between the hornplates. The other shows the boiler with machining completed and the firehole and damper door assembly fitted. This design has a marine type firebox very similar to the Sweet Pea railway locomotive, hence the unusual looking arrangement. The next step is to fit the smokebox, then mount the boiler at 27 degrees to the horizontal. Richard comments - "For a design the original manufacturers entitled 'Simplicity,' construction of the model is proving to be anything but!"

February 16, 2020.

There was a need to make some adjustable stands to align the horn/boiler/smokebox components. Using 12mm setscrews, a built up method of construction, rather than machining from 2inch bar, has been used to cut down on the amount of swarf produced. A few drops of retainer and job done. It's just possible to see one of these stands holding the hornplates level. If anyone has a 3inch scale Ben Hur action figure they no longer play with, Richard would love to have it?

February 23, 2020.

Smokebox now fully bolted to boiler - Jacked, packed and tacked ready for completion of hornplate to boiler bolts. Fingers crossed it doesn't move!

March 1, 2020

Boiler mounting completed, I'm happy to report that four years after starting this project the roller now actually rolls! The target angle of the boiler is 27°, but as the photo shows it has ended up at 27.1°. I contemplated 'falling on my sword' at such a dismal failure on my part, but have taken comfort in the fact that very little in life is ever perfect. So, rather than consigning the roller to a skip, I have decided to struggle on. Incidentally, I cannot praise these digital angle gauges highly enough. I've had this one for many years and used it both professionally and at home. Without it setting up the boiler would have been quite difficult.

March 8, 2020

This week I decided to erect the steering gear. It's quite a novel way of steering, using as it does a worm and gear quadrant, as opposed to a drum winding a chain as most other road steam manufacturers employed.

You can see it's very straightforward in principle, but unfortunately there does seem to be a tight spot in operation. I have two choices, either use feeler gauges to determine any error and apply all the manual skills of a neuro-surgeon to shim out any imperfection, or failing that, employ the services of a 2lb hammer. I suspect that in actual fact the steering shaft, despite being made from ¼ inch dia stainless, is flexing. This can be rectified by a support bracket mounted on the side guard once that is made and fitted.

Please note that I did not cut the worm or gear teeth as they came with all the other cut gears, thankfully!!!!

March 15, 2020

March 22, 2020

It's now time for a bit of detail work. Here can be seen a rear lamp bracket just after bending and ready for drilling and a clean up.

The next photo shows them both (yes both sides of the roller are thus equipped) bolted in place along with footsteps and the towing pin.

Finally the differential gear guard is shown fixed in place on the spectacle plate. The drawing shows this as just a simple rolled strip open at the sides, and in my opinion it looked ghastly. So I welded on some sides and then brazed it to a baseplate rather like a loco wheel splasher; much better, and if any rivet counter criticises it, they'll be told "my model, my rules".

March 29, 2020

This time it's the turn of the eccentric driven boiler feed pump, crankshaft bearings and gear selector fork and bearing. I made the pump  about four years ago as one of the first items on this project. A neat little bronze casting for the pump body with the valve box from bronze bar silver soldered on after machining.

It's not ideal from an operational viewpoint in as much as it's driven from the final drive shaft, so unless the roller is moving it ain't pumping anything! Just behind the pump can be seen one of the crankshaft bearings, the body of which is an aluminium casting with separate bronze bearing, pretty conventional. Inserted in the bearing is a blank turned the same size as the groove in the crankshaft gear. This was done to enable positioning of the gear selector fork housing whilst there was still room to get at it!

If you haven't noticed the feed pump stay has now been cut down to the finished height. This was deliberately made too tall to give me something to stick the angle gauge to whilst setting up the boiler for bolting to the hornplates.

And finally, the belly tank mounting brackets, made from simple steel angle. There is quite a bit of steel angle used in the assembly of hornplates, stays etc. All these angles have been up-cycled from a pair of old car ramps from back in the day when I used to love tinkering with old motors. These hot rolled angles have been machined both square on the outside faces and down in width from 1" to ½".     

April 5, 2020

I fancied a change from machining and fitting so decided on a bit of sheet-metal work.

What you see before you now are the two side guards, not that they're actually guarding against anything at the moment! Produced from 1.5mm thick steel, the first stage of manufacture is the forming of a 12mm radius bend at the front end. As you are all no doubt aware there are various ways of producing this.

The simplest way is to place a suitable mandrel in a bench vice and wrap the sheet over it with a mallet; but because these bends have to be made at 27° off square, I decided on a more accurate method.
This was achieved using the fly-press, a very much underrated tool in my opinion. I have shown a selection of various small radii forming tools made over the years. Larger radii are much easier to form in bending rolls, or even by hand over a suitable bar, such as the one shown - tack welded to a flat plate for ease of holding it in said bench vice.

Another photo shows one of the guards being formed in the press, this is a posed shot taken after completion, just for illustrative purposes. The forming of the brass beading was not without complication either. When you come from a flat to an inclined radius the bend becomes conical, requiring much annealing and shaping to get the ¼inch half-round section, to flow around the bend without leaving a gap at the top; easier said than done!

Finally, setting the guards off a treat, are the cast gunmetal makers plates. These cleaned up easily with files and emery, apart from the backs, which were as rough as the proverbial badger's botty and so were fixed to a plate and given a light skim with a flycutter to true everything up, very nice. More sheet work to follow next week.

April 12, 2020

I now came to a part best described as 'shall I, shan't I', bother that is, as in my opinion there's no real need for it. There is no title for this part on the drawing but it is obviously a boiler stay/support. Now the fact that there are already 23 M4 bolts attaching the boiler to the hornplates, I doubt that this part is needed for structural strength, but, as can be seen from one of the photos, a large gap existed between the firebox end of the boiler and the spectacle plate.

The complication is this part starts as a flat horizontal section transforming into a curve which itself is at an angle of 27° to said horizontal. Now despite gaining City and Guild's accreditation in 'Thin Metal Craft Studies' (that's 'sheet metalwork' in everyday terms) at the tender age of 20, nearly 30 years ago now (Webmaster comment - obviously no C&G maths!), I rated my chances of producing this part (from 1.5mm mild steel) without a former, about the same as winning 'Euro Millions' on two consecutive draws!

Production of a former would have taken an eternity, so fabrication was the easiest answer. A start was made with a strip of steel being rolled to the diameter of the boiler.

The flat component was cut out and then placed over a round bar in the bench vice and the front corners carefully shaped with a mallet to match the rolled band. The flat component was then clamped to the spectacle plate and the rolled strip laid on the boiler and brought into contact with the flat component. A couple of tack welds in situ and then removal for full welding. After stretching the weld back by peening with a hammer, as shrinkage always occurs causing distortion, the weld was dressed up with files etc. to give what you see here. Lastly the part was drilled and riveted to the mounting angle and dummy rivets fitted to the curved surface.

The final photo shows it fitted in place and spanning the gap nicely, well worth the effort. So, from 'shall I, shan't I' I progressed to 'might as well' and in the final analysis..... 'I'm glad I did'.

April 19, 2020

Attention was now turned toward the boiler feed water clack valves. The bodies were supplied as bronze castings and presented no drama to machine, just a nice straightforward lathe job. After sawing off the chucking spigots they were treated to some TLC with files etc. and, as luck would have it, completed right on cue for elevenses. The pair were taken indoors to show Her Ladyship and on picking one up she said, "And this is a?" - "Clack" - says I. She responded with "what's the other one called, Clickety?" Oh everyone.....how we laughed!

After the Earl Grey and Neopolitan wafers had been consumed, it was back into the workshop to face the challenge of fitting the valves in position. It was not possible to clamp them to the boiler and spot through with a drill, so a drilling jig was called for. This was simply a piece of round bar, clocked up in the mill to centre it under the machine spindle, then drilled, using the DRO, to the same co-ordinates as the flange holes on the bodies. Then, without removing the jig, a further two holes were drilled across the face and tapped M4 to take a couple of cap-head screws; these were to be used to rest the angle gauge on in order to get the jig set horizontally.

Now, when the boiler was fabricated, despite the drawing showing the clack valve bushes with plain holes, it was decided to tap them both ¼ x 40t in order to take blanking plugs I already had for the hydraulic test; so a screw was machined to hold the jig in place on the boiler. The jig is quite thick as these holes had to be drilled using only a hand-held electric drill, so maximum guidance for the drill bit was desirable to prevent wandering off square. Screwing the jig on it was then adjusted with the angle gauge to horizontal and tightened up, double checked, then drilling cautiously commenced. Tapping the blind holes M3 proved quite nerve racking because, as you can imagine, a broken tap at this stage would have been a disaster! All went well though, studs were made and fitted, and both valves slipped on easily and perfectly level.

 Another job done. Right what's next?

Determined as I am to submit something each week, I have a need this time to backtrack to the very beginning of this project, as, due to a blocked domestic drain, resulting in me laying on my side, on the drive, up to the armpit removing something best described as 'rather unpleasant' from a clay pipe, progress this week has been somewhat limited.

Now, when I bought the set of secondhand castings for Simplicity, they were thankfully, un-machined, except that is for the rolls, wheels, rollers - call them what you will. These came supplied with the outside diameters turned, faced to width plus the bores and gear-ring spigots finished, which at 11" diameter for the rear and 9" for the fronts, were well outside the capacity of my lathe. The full size rolls were fabricated, using inner and outer flanged steel plates bolted to a central axle tube and the resulting assembly then being riveted to an outer steel band which formed the 'tyre'. There are full details on the drawings for the builder to adopt this method of construction if so desired. No thanks!

Back to the model, the rolls, being iron castings, required to have the removal of the rough cast finish to something much smoother and more in-keeping with the steel plate of the original machines. This was achieved using a flexible disc on a small angle grinder. The large holes seen in the 'flanged end plates' had rough cast edges and so all were skimmed on the mill with a boring tool to both clean them out and bring them to a uniform size. Dummy studs and nuts were fitted to emulate the fixings of the axle tubes to the end plates. Holes were then drilled and countersunk around the periphery of the rolls to take dummy rivets to imitate the outer tyre to flanged plate fixings.

In order to fit the rivets, the rivet snap required a slight overhang from the end of the vice so a snap was cut down and welded to a piece of 1½" x 1" bar which was then securely held in the bench vice and riveting began. There are eighty two ⅛" diameter iron rivets in total, and the roll castings are rather heavy to say the least. After about 20 or so rivets I realised that, despite being blessed with the physique of Adonis, my arms were not meant for heavy manual labour. So a dozen at a time from then on, then do something else, just for a rest, such as carefully filing the already fitted rivets down flush with the tyre. The front rolls were treated in a similar manner.

Another job tackled, whilst waiting for my arm to stop aching, was the fitment of the drive gear-rings. After drilling clear for M6 cap-screws, the rings, being a very close fit on their mounting spigots, were carefully driven into place with a piece of timber, hoping and praying they didn't become wedged halfway down (or even split!). Drilling and tapping of the rolls then followed resulting in a lovely, secure job. The last task to be performed was to press in the Oilite axle bearing bushes and job done.

Well that's it for this week. Now I hope you'll excuse me but I have this strange compulsion to go and wash my 'drain' arm, AGAIN. I don't think I'll ever forget that smell!

May 4, 2020

With no domestic dramas needing to be sorted this week, it's back to business as normal, whatever the 'new' normal is! The topic this time is PPE; purpose-made pipe elbows. No doubt we are all aware of the excellent commercial items that are available from the Trade, but sometimes they are either unsuitable or simply just don't look right, with customised elbows being much more desirable.

Here is a prime example; the elbows that are screwed directly onto the water pump. These are strangely not shown on the drawings and are left to the imagination!

Of the two shown, the shorter is the in-feed to the pump from the water-tank, and the longer the delivery to the boiler clack plus pump bypass back to said tank.

It would be foolish to say that this method of producing elbows is the best way, but in this instance it worked out well. So, if you're still interested then read on regarding Howie Diddit.

Lurking in the odds'n'sods box were several flat bronze bar offcuts, 10mm thick, surplus from a fancy lift-car hand-rail job, gifted to me from an admirer. This was to be the material of choice, in this instance, and the required elbows being thus produced from the solid. The first stage was to saw out the L-shaped blanks then chuck in the 4-jaw to turn the longer of the two legs down to ⅜" diameter. Thereafter drilling along the length 5mm, being careful not to go past the centre-line of the yet to be machined second leg. If drilled too deep there is then a strong possibility of breaking through into mid-air when shaping the corner! The final lathe operation was the drilling and tapping ¼" x 40t for a short distance, to allow the screwing in of hex brass end-fittings, to be added later.
 

The next set of tasks were performed on the milling machine, the first being to mount the newly turned section on a parallel, in the machine vice, for the 'vertical turning' of the second leg. It can be seen in one of the photos how this section is starting to be formed. The more experienced machinist will probably have noticed the use of an opposite hand boring tool, as opposed to a standard one. This was necessary as my cheap Taiwanese mill/drill, of 1980 vintage, does not have the luxury of a reverse switch. If it did then a standard tool could have been used; fitted in the boring head back to front, so to speak, and the spindle then run in reverse, a task performed often during my time in industry.

After machining the second leg to the same diameter as the first it was then drilled through to connect with the previous 5mm hole, then coned with a centre-drill for the pipe nipple and lastly threaded for the union nut, using the lathe's tailstock die-holder fitted in the machine spindle. After removal from the vice the resultant work-piece is seen in another of the photos. Taking advantage of the ¼" x 40t hole, the elbows were screwed in turn onto a threaded rod held in the bench vice to enable shaping of the square corners into a more attractive radius using files etc. The  brass hex end-fittings, internally threaded 5/16" x 32t to suit the pump connections, were then silver soldered in and the bypass manifold had the delivery pipe connection stub added also. Incidentally, this stub was machined from a chucking piece sawn off a previous casting - waste not want not!

The completed elbows are pictured after receiving a clean-up and also fitted in-situ on the roller. I hope you'll agree with me that they look a lot smarter than yer standard pipe elbows! A commercial globe valve being utilised for the bypass control is also shown fitted.
 

To round off this weeks offering you can see three fabricated brass elbows, from 6mm diameter material, left over from a batch previously produced for the 'should have been finished years ago' Ivatt 2-6-2t project (completion of which is scheduled after Simplicity).

These particular elbows have pilot holes only, being opened up or threaded as required.

Next week things get much more serious.

The crankshaft!!!!

In amongst the second hand casting-set was a piece of flat steel bar, obviously meant for the crankshaft. This had previously been roughed out by milling. Judging by the amount of scale on it's surface it appeared to have been heat-treated, most likely stress-relieving, to help prevent it resembling one of Fyffes products after machining. Had this embryonic crankshaft not been included then the crank would have been produced by fabrication, using the time-honoured method of Loctite and pinning. But then being the sort who has a fetish for 'machining from solid' it would go against the grain not to use it. So, nothing ventured and all that.

In the beginning, the ends of the blank were centre-drilled in the relevant positions then mounted twixt headstock and tailstock. The crankpin was the first part to be machined and thus was roughed out to within 0.020" of finished size with a sturdy parting-tool. My lathe is a 1942 built Cromwell 3½" x 20". With a flat belt drive, and a very rigid construction, parting-off has never been a problem, and neither was this roughing-out operation. The photo shows the parting tool used. It has a ⅛" wide, ¾" deep, stiff T-section blade, with a semi-circular groove running along it's entire top edge. When used purely for parting-off one only has to grind the front face, making sharpening quick and easy. You can also see just how far out it had to protrude from the holder (approximately 1½") in order to do it's stuff.

Now rather than grinding up a long slender turning tool from scratch, in order to finish turn the crankpin, the decision was taken to adapt the self same parting tool used for roughing. So, with some trepidation, the front cutting face was ground back at an angle to provide clearance and then the tool-post angled slightly, thus converting the blade into a narrow turning tool. Firstly to get from the centre of the pin to the left hand side of the crankweb, then ground and angled in the opposite direction to finish to the right hand side. The existing groove along the top edge of the blade gave enough top clearance/rake etc. without needing any further attention. Taking light cuts only, it was an absolute doddle to finish turn the crankpin. After fitting a support screw and nut, lightly extended between the crank-webs (in order to prevent pressure from the tailstock centre causing distortion) the remaining parts of the crankshaft were turned using a conventional turning tool. In hindsight it's a pity the valve gear eccentrics weren't turned integrally with the crank as this would save having to set them by hand later. The final operation was the machining of the four drive-gear key-ways using an indexer on the milling machine, no problemo. And that concluded the crankshaft machining. Let joy be unconfined!

The next job tackled was the production of the key-ways in the drive gear bore, which gave quite a lot of unexpected grief. The gear itself came with the teeth already cut, along with all the other gears, so it's uncertain exactly what material it is made from; but it is quite tough and kept deflecting the key-way planing tool. This planing tool-bit is ground just as a parting tool but set on its side at centre-height, then advanced into the job 0.001" at a time and traversed through the bore using the top slide. It's the very same tool that has previously been used for planing keyways in other components, without I might add, any problem whatsoever. Well, after making a right pigs-ear of the bore, frustration set in. By now the bore was beyond redemption so it was machined out and an HE30 aluminium insert Loctited in. After boring the insert back to size the planing of the keyways was now straightforward, although I do wonder how long aluminium will last in service, only time will tell!

Not owning a dividing attachment for the lathe spindle, the gear was indexed round into position using the digital angle gauge held against a chuck jaw. After planing each keyway, the chuck was rotated 90° using the gauge. This process was repeated until all four grooves had been cut and the job came out well. To be honest the keyways did require a tickle with a needle file to get the gear to slide smoothly over the keys, but overall 'twas a pleasing result. The ⅛" square section keys themselves were cut from gauge plate using a slitting saw.

Another photo shows the crankshaft in company with the valve gear eccentrics and straps (nothing untoward in the production of these) plus the keys and the problematic drive gear. There is also a close-up shot of the gear showing the aluminium insert and keyways in greater detail.

The flywheel was the final crankshaft ancillary to be undertaken. A simple turning job this. After roughing out the casting all over and then boring for the crankshaft, a 'wring-fit' mandrel was produced, with tailstock centre support, onto which the flywheel was 'wrung' for finish turning in order to keep everything concentric. There's nothing worse than a wibbly-wobbly flywheel! The smaller hole to be seen is for a fitted bolt to hold the flywheel securely against the side of the crank web. And finally, at long last, the crankshaft assembly, minus eccentric straps, is shown mounted all tickety-boo between the hornplates, the gear sliding and meshing nicely. In closing let me just say that this group of components took considerably longer than one week to produce!

May 24, 2020

As Ken Dodd might once have said; "What a wonderful day for going up to a neighbour and saying "How's this for a big-end missus?" I am, of course, referring to the connecting rod.

After making three locomotive chassis this particular con-rod made an interesting change from rectangular fluted rods, being of a circular cross-section and tapered to boot. Now not having a taper-turning attachment the lathe top-slide had to be slewed over to the required angle and the rod turned between centres (using a round nosed tool). Due to the rather limited travel of the top-slide the taper required turning in three sections. No matter how much care is taken there is always a slight ridge where one section stops and the next starts, so a needle file and emery were then used to blend the 'joins' so to speak.

This type of con-rod is a lot easier to produce than the loco variety. The main body, in this instance, was produced from 30mm dia mild-steel, making quite a lot of swarf. I sometimes wonder if our bin-men ever notice how 'our' bin always seems heavier than everyone else's! But I digress. After the turning was completed it was then over to the milling machine to create the flats, drill all the holes and round off the small-end, and that completed the actual rod.

The big-end bearing was next up. This was a one-piece bronze casting, the first task being to slit it into two halves. Subsequent operations, although not creating any problems as such, did seem to take an inordinate amount of time to machine. The studs also required a great deal of care, being so delicate; the stop collars are 3/16" dia with the remainder ⅛" dia threaded 5BA, plus an oil clearance groove needing to be machined in the upper stud.

The small-end pin is just that, a pin, fixed into the con-rod with a grub screw. The pin will eventually run in bronze bushes fitted into the crosshead.

So that's it, job done, nothing flash, just an enjoyable machining exercise, which in my opinion has turned out to be a 'thing of beauty'; not as beautiful as Norman Johnston's wooden Midland Compound driving wheel pattern I grant you, but beautiful nonetheless. How tickled I am.

Next week: the start of a 'magnum opus', the cylinder block.

May 24, 2020

Some model engineers regard the 'heart of the machine', when applied to a steam engine, as being the boiler. Others will argue against that and say that it's the cylinders, or in this particular case, cylinder (singular). I dread to think how many hours have gone into producing this cylinder block and all its ancillaries, but then Rome wasn't built in a day! Its vital statistics are 1" bore and 1½" stroke

The first task, as with any casting, is to clean off the lumps and bumps, any moulding sand and general detritus. If you want a sure-fire way of blunting a decent file then simply use one to clean up an iron casting! Whilst this task was being undertaken much thought was being given as to how to proceed with the machining in a logical manner. So, after measuring and checking just how much metal was required to be removed, a decision had to be made regarding which 'face' would become the datum i.e. the starting point from which all other measurements could be taken; to ensure the casting cleans up, which it did -  but only just!

The datum chosen was the steam-chest cover face. Duly skimmed flat then drilled and tapped for the cover studs and we're off, no turning back now! A steel block of 2" x 1" section, and about an inch longer each end than the block, was then drilled to the same co-ordinates so it could be bolted to the steam-chest face. This 2 x 1 could then be clamped to an angle plate, held in the machine vice or clamped directly to the milling-machine table, as required, to enable the majority of the subsequent machining. It's worth mentioning at this point that the cylinder block casting was machined entirely on the cheap Taiwanese mill/drill using the facilities of its DRO, an invaluable aid.

Various photos show the cylinder's main areas of interest. Overall the job went well but the steam-chest port-cutting needed a bit of a helping hand. The outer inlet ports are only 3/32" wide and the depth of the steam-chest, plus the depth of the ports combined, was much deeper than a standard slot-drill would allow; that is if you wanted to see what was going on at the cutting face. Long-series cutters of this size are rather fragile to say the least, so a standard length cutter was Loctited into a ¼" dia. reamed hole in a ⅜" OD rod around 2" long, which after being left overnight to cure was then held in the machine spindle using an end-mill holder as opposed to a chuck; this effort gave much better visibility. The beauty of this cutter holding method is that after the job is done one simply heats the assembly up to around 250°C to break the bond and the cutter can be withdrawn from the ⅜ rod none the worse for the experience (which is why there isn't a photo of it!). The second 'helping-hand' was to chain-drill a series of holes 1/16" dia. along the centre-line of the ports so as to reduce the amount of metal the milling cutter has to remove; if you look closely at the photo showing the ports it is just possible to see the dimples at the bottom left by the drill.

The cavity on the top face of the casting is the regulator-chest, complete with a teardrop shaped port, which hopefully will aid slow tick-overs. The sticky-out lumpy bit on the rear face of the block, complete with two studs, is the valve-spindle boss, a separate piece of cast-iron bonded in. On the subject of studs, all of these holes were drilled and tapped before the actual covers themselves were even made, using co-ordinates from the DRO. After the covers  have been produced they were then drilled using these same co-ordinates and all fit like a glove. A fellow, much respected club member, told me once that despite having a DRO he would still drill the covers first then clamp and spot-drill through to ensure alignment; oh ye of little faith!

Last, but certainly by no means least, came the machining of the 2⅜" radius concave saddle-face to fit to the boiler barrel. Just to add complication this face is machined 1½° to the cylinder bore to bring the centre-lines of bore and crankshaft into alignment. The rather crude home-made fly-cutter used is shown. Now assuming grey-iron has a cutting speed of around 80 ft/min, this dictates a spindle speed for a HSS cutter of just 60 rpm. The mill's slowest speed is 200 rpm! Light cuts, and two tool regrinds later, the job was done, albeit noisily! This concave face finally cleaned-up with just 0.010" left to cut. Now that's close!

As road-steam cylinders go, the one for 'Simplicity' is relatively straightforward. Now, to anyone who has ever machined a steam-jacketed, compound cylinder block, I have only one word. RESPECT.

May 31, 2020

Now follows the first of the cylinder block 'bolt-ons', the trunk-guide. With this being the part that supports the crosshead in its travels, it's only right and proper to show a picture of the piston/rod/rear cylinder-cover and crosshead.

Simplicity is available, in model form, in a choice of scales viz. 3" or 4½". A casting for the trunk guide is available in the larger scale but not for this 3" example. The valve spindle-guide bracket though is available as a bronze casting, requiring machining and then silver-soldering to the main body which is specified as being machined from bronze bar. Exactly how expensive a piece of 2" dia. bronze would cost I do not know but I wager it ain't cheap! As luck would have it an off-cut of 'Glacier' cored bearing-bronze had been kicking about in the workshop for many years. Measurement confirmed it would just about clean up, so now the time had come to make use of it.

The main body of the trunk-guide was turned from steel and the bronze insert silver-soldered in, along with the small upper oiling-pot. The ⅛" thick gussets, between the end flange and the main body could only be held in place by carefully drilling and tapping 10BA into their ends, and then held with screws through the end flange. One of the photo's shows the screw-heads recessed slightly below the flange surface. The resulting fabrication was then treated as if it were a casting and bored and faced etc.

The valve-spindle bracket casting was machined and, as shown, a simple fixture knocked-up to hold it in place for silver-soldering to the main body. The final photo shows the trunk-guide fitted to the cylinder block after which the valve-spindle was tried for fit, which thankfully was OK. The brass fitting seen screwed to the side of the cylinder block will eventually form a steam take-off for the injector steam-valve supply.

So that's it for another week. As I said recently to our Webmaster-General, it's a pity these components can't be produced as quickly as it takes to write about 'em!

June 8, 2020

So then, just to recap. There now exists a crankshaft, connecting-rod, trunk-guide, piston/crosshead assembly and cylinder block. It is worth mentioning that all these items have been made exactly to the drawings in 'blind-faith', hoping there were no draughtsmans errors, which are not unheard of in model-engineering, or general industry either for that matter. The next logical step was to bolt the cylinder-block to the boiler and then assemble all the parts together to make sure everything fitted as it should.

The cylinder was lined up with the crankshaft etc and temporarily held in place using 5-minute epoxy adhesive. (Only a couple of small spots as the cylinder has to come off again!). The bolt-holes were drilled via the cylinder casting and through the boiler shell M4 tapping size and the casting then removed from the boiler with a sharp slap of the hand. After tapping the boiler barrel the cylinder was drilled M4 clearance and then temporarily bolted to the boiler. The completed parts were then fitted together and, after some initial tightness, the assembly began to free-up (or wear-out depending on your viewpoint) and everything deemed acceptable.

Now the drawing shows the cylinder-block finally bolted to the boiler into blind-tapped copper inserts screwed and soldered into the barrel which is ⅛" thick seamless copper tube. The insert's external thread is shown as ⅜" BSF, not a common thread these days but having the relevant taps and dies it was decided to stick with this. It's been found from experience that fairly large diameter and coarse pitch threads such as this cannot be formed easily on this lathe by die alone. The work-piece either slips in the chuck, or collet, or else the die is difficult to turn, or both. The solution therefore was to partially screw-cut the thread using a single-point tool to about 90% depth, then finish the thread to final size with the die, thereby relieving the strain on both machine and operator! A nearly finished screw-cut thread can be seen with another photo showing three of the finished inserts after sizing with the die. The boiler is also pictured drilled and tapped ready to accept the inserts.

Of course, all this drilling and tapping of the barrel produced a substantial amount of copper swarf which had obviously fallen through into the boiler, and it all had to come out! The air-line was connected to the boiler blow-down bush and a blast of compressed air soon had the little copper fragments fleeing through every available orifice: "They don't like it up 'em Captain Mainwaring".

With a now clean boiler it was finally time to fit and solder in the inserts. Looking at the photo it would appear as if the Comsol had been applied by a pigeon, but after filing the inserts down level with the boiler barrel all looked respectable again. Incidentally, these insert holes had been given a shallow countersink in order to give the Comsol a chance to seal around the insert. Remember, the strength of the joint is the screw-thread, the solder is merely a caulk!

Having shed all this blood, sweat and tears, the boiler was now completed and the time had arrived for a hydraulic test. The working pressure is 90psi, so, as we all know this dictates a shell-test of twice this. The test-gauge is shown, with the pump disconnected, at 180psi, which was held for the time taken to consume a mug of Darjeeling and half a dozen custard creams, before slowly releasing the pressure.

The final shot shows the cylinder block fitted to the boiler with phosphor-bronze bolts, machined to imitate studs and nuts. All the threaded fixings for this model (larger than 6BA) have been machined 'in-house'. This way they can be made the correct overall length along with the desired ratio between plain-shank and thread. The round headed 'rivet-bolts' in the smokebox were turned a slight interference-fit in their holes to prevent rotation when tightening. All nuts are commercial items - I can't make everything!

June 14, 2020

The fitting of the water gauge comes next. Due to the sloping boiler it was not possible to determine the position of the lower gauge-bush until the cylinder block had been temporarily erected. One of the photos shows the Heath-Robinson method of marking out the hole centre for the bush, for if the water gauge is not vertical it will look hideous!

It's a strange layout this, compared to the more usual backhead mounting, having the top water-gauge fitting mounted on an extension from the cylinder block, but then, due to Simplicity's design, there is no alternative. The extension was turned from phosphor-bronze and was a real pain to drill, turning blue due to the heat generated despite using a freshly sharpened drill and frequently withdrawing it from the job and flooding it with coolant. Strangely enough, though, the bronze turned and threaded with no problem. After drilling and tapping the boiler barrel the lower gauge bush was soldered in along with all the other required bushes.

Now ask yourselves who wouldn't want three cocks? It would be nice to say this superb tri-cock water gauge was lovingly crafted here in 'the workshop that time forgot' but it would be a lie (it was purchased from e-bay). It can be seen mounted on the boiler with a test-rod through the two fittings to get them lined up.

Yet another job struck off the long list!

June 22, 2020

Short and sweet this week, the dummy boiler mud-hole door. The components are shown both separately and fitted. The flanged stud screws into a blind bush and pinches the door against the boiler barrel, and the clamp, a bronze casting, slides down the stud and holds the reinforcing ring ditto. That's about it for the boiler except for the cladding sheet and boiler bands which will probably be made towards the end of the build.

Before moving on to the cylinder fittings, take a look at the smokebox tubeplate. No superheaters, no snifter, no steampipes, no blastpipe, no petticoat pipe, no blower connections and no stay ends, it doesn't get any more 'Simplicity' than this! But before the boiler inspectorate break out into a cold sweat, due to a lack of longitudinal stays, be assured there is a hefty U-section silver-soldered on the inside of the tubeplate for support.

June 28, 2020

The first of the controls is next up - the regulator. What a joy this was to both make and assemble considering how inaccessible most railway locomotive regulators are!

The valve itself is a plain sliding block covering/uncovering the port (which was shown in a previous update concerning the cylinder block). The brass bushes on the spindle, either side of the valve, are the travel stops and the valve-spindle itself can be seen supported in a bronze gland at either end of the regulator chest.

A long operating rod connects the valve spindle to the regulator handle mounted on the spectacle plate, shown in both close-up as well as a general overall shot. Now if only all jobs were this straightforward!

July 5, 2020

Now let's be honest, who doesn't like to blow-off once in a while? I know I do. Well the device every boiler requires to do just that is the safety valve - the subject of this week's update.

Simplicity's safety-valve assembly comprises a cast-bronze main-body into which are screwed two separate brass valves which both exhaust via a common elbow into a pipe which will carry the spent (or wasted) steam up through the canopy, and away to atmosphere. The valve assembly is then bolted down onto the regulator cover.

The components that required the most thought were the two brass valve-bodies due to each having eight 'spanner-flats' as opposed to the more normal six. Now with the milling machine's indexer only having sixty holes, it could not be used to create eight flats. So how to produce eight equal flats? An idea eventually sprang to mind.

Taking a piece of 1" square bar, a hole was drilled centrally along the bar's axis to take, in this instance, ⅝" dia. The valve bodies were then turned to this diameter and at the same time the threaded bases were produced. The brass bodies were slid into the square bar and pinched with a grub-screw, thus making a holder.

The holder was placed in the mill's machine-vice and, turning it over four ways, four flats (or a square!) were machined on the blanks. The holder was then placed in a V-block, which tipped the job 45°, and once the cutter depth was set, the process was repeated again to produce yet another four flats, which resulted in a perfect octagon. The brass valve-bodies were then screwed into a threaded bush in the three-jaw for completion of valve-seats and body profile etc.

The stainless steel valve-spindles required a lot of care, or rather producing the 1/16" wide lifting-slots did. Only one slot-drill was available and after chain drilling away most of the surplus material the cutter broke on the very first pass!!! Naughty words. So needle file to the rescue the slots were filed instead of milled, albeit slowly. (Very slowly!)

July 12, 2020

The next 'cylinder bolt-on' is yet another part not detailed on the drawings and left entirely to the builder's imagination - the cylinder lubricator. The one used here is a 1" square commercial item which was supplied with a standard pressed-brass lid. Nothing wrong with that I grant you, but a more prototypical look was desired. So a  replacement lid and hinge assembly was machined from steel, making a big visual improvement on the original plus the fact that, unlike a loose lid, it cannot go missing!

With the lubricator now 'tarted-up' the next task was to fix it onto the cylinder block; so a platform was folded up and fitted, along with a stay-bar for extra support.

A form of drive to the lubricator is obviously required and a common method would appear to be an upright clamped to the valve-spindle, push/pulling a rod connected to the drive-arm. Here is an interpretation of this method and the components are shown both individually and then fitted in-situ.

The oil delivery pipe can be seen connecting the lubricator to the oil check-valve on the steam-chest cover. In addition, the bronze square-headed plug, located top left of the  cover, is an oil-doping plug, again, not shown on the drawing; but with Simplicity having a cast-iron cylinder/piston etc. this plug will be removed after each steaming and WD40 flooded into the steam-chest/cylinder to, hopefully, prevent seizure due to rusting (as was experienced with the Jubilee loco many moons ago).

So, from having no drawn details whatsoever of a cylinder lubrication system, everything has worked out very nicely. You could say "oils well that ends well."

July 19, 2020

Continuing with the cylinder 'bolt-ons' the pressure gauge came next. This is mounted on another folded bracket fixed onto the regulator cover, and as such required its supply pipe to have a rather convoluted bend, in order to provide a decent syphon (or is it siphon?).

Another simple job, needing no explanation, therefore it won't get one - the brass cylinder cladding sheet.

Cylinder drain-cocks. Bought on e-Bay they are of excellent quality. Advertised as intended for stationary engines, they had to be modified by threading the outer ends to accept drain tubes. It's been considered too much trouble to fit the 'linked' variety of drains, which would need an operating linkage running through to the footplate, hence this simple independent type.

Two more e-Bay purchases, the whistle itself and the whistle valve. The only components requiring to be made for these two items were the banjo fitting, coming off the regulator chest, and an adapter in order to marry up the whistle to the valve. This project is fast becoming an e-Bay kit!

The boiler filling plug is also now made and fitted. This is the oval gunmetal flange with a removable square-headed plug, seen just below the steam chest. And finally for this week, the safety-valve elbow is now fitted with its brass exhaust tube.

July 27, 2020

At last, the final part bolted to the cylinder block: the exhaust-pipe. The drawings show nothing more than a schematic view depicting a flanged parallel pipe coming off the cylinder block, and entering into the chimney base casting, whereupon it turns to point up the chimney and simultaneously tapers down to blast nozzle diameter - all in one piece. That was decided against and a built-up system using separate components (flange, pipe, elbow, locknut and blast nozzle) being much easier to produce, plus it would be adjustable.

The exhaust pipe was produced from copper and is bolted to the block via a silver-soldered steel flange. The smokebox end of this pipe has a male 7/16" x 40tpi thread to accept the elbow.

Now with the boiler sloping, yet the chimney vertical, the exhaust elbow has to be angled to suit. Manufactured in a similar manner as previous elbows, this one is shown screwed onto a mandrel, threaded as stated 7/16" x 40tpi, and held in a V-block set at the required angle for machining the short end. Machining completed the elbow was rounded and smoothed off as before.

The blast-nozzle is simply a piece of brass hex screwed into the elbow. The exhaust assembly is shown, minus the chimney base, to give the overall idea.

After bolting everything up, the elbow then has to be set to align with the chimney. One plane is non-adjustable (that of the boiler/chimney angle, fixed when machined) but the other two planes require attention. The elbow is first adjusted on the exhaust pipe to centralise it within the chimney base aperture. Obviously the minimum amount it can be moved is one complete turn, which on a 40tpi thread gives a maximum error of 0.025"; I can live with that!

The final adjustment is the second vertical plane, achieved by screwing a rod into the blast-nozzle thread and then setting true with the digital angle gauge. Once all is well the lock-nut is tightened. Job done!

August 3, 2020

Over the years I have on occasion heard it said that "confession is good for the soul", so here goes. When last week's update was viewed it may have been considered by some that, yet again, Yours Truly had created another shining example of model engineering. What wasn't disclosed at the time were the two monumental faux-pas committed in the production of the exhaust system.

The first was when it came to the final shaping of the exhaust elbow, after the initial machining. I completely misjudged the angle required when sawing off the lower corner ready for filing, thus revealing a very neat hole about 3mm diameter. My apologies for not including a photo of this disaster but I hope you'll understand that it's impossible to operate a camera whilst holding your head in your hands.

Now rather than binning the elbow, a scraplet of brass was silver-soldered over said aperture and shaping resumed. The final result puts me in mind of those awful sports-jackets with the leather elbow-patches, which were all the rage back in the Seventies. But worse, much worse, was to follow the next day.

Now not having any detail drawings for the exhaust components, I deliberately made the parts too long with the intention of trimming them back to fit, once the true lengths could be determined. The copper exhaust pipe, complete with its steel flange, needed facing back to finished length and then threading. Too much was left protruding from the lathe chuck, and, being soft copper the tool dug in, kinking the pipe and mangling the flange. This fabrication was now beyond salvage and had to be remade. The original now resides in 'landfill' somewhere. Yet again, apologies for the absence of a photo, due to the reason stated earlier.

With two easily avoided, and let's face it, stupid mistakes (on two consecutive days) Her Ladyship had become increasingly concerned with regards to my mental state, and so booked me in for 'consultation' with a health professional. After an intense forty-five minute interrogation the diagnosis was that I was suffering from an acute case of 'Ignorance and Indifference'. Well I've absolutely no idea what that means and furthermore I don't even care, I've got a roller to crack on with!

 

August 9, 2020

With the 3 inch scale Simplicity having a reputation for poor steam production, it was considered prudent to have a blower, for when things need livening up! At the risk of sounding like a record, no details of a blower are given on the drawings; in fact looking at photos of the full-size machines they appear to never have had one fitted, which probably explains why! It was intended to try and keep this home-grown blower arrangement as 'discreet' as possible.

The first requirement was a steam feed. A hole was drilled and tapped ¼ x 40tpi in the front face of the cylinder block and through into the steam cavity at the base of the block. Into this hole was screwed an extension piece, and then into that was screwed a globe valve. One of the photos shows the valve 'stripped-out' to enable it to be spun into position.

An elbow was needed to come off the chimney-base casting, so this was fabricated and then fitted into a drilled and counter-bored hole, being held captive on the inside of the base-casting with a thin nut. Another much smaller elbow (into which fits the blower-jet) was then screwed into the back of the main elbow, the assembly becoming rather like a set of Russian dolls.

When all was mounted-up the valve obviously needed piping up to the elbow and 1/8" dia. copper tube was used. The space between elbow and valve is quite tight, only 1" apart with a ½" offset; I've included a photo taken looking directly down to help show this. There is also a small offset in the vertical plane, but this is easily overcome by simply swivelling the pipe round to suit. Now, not owning a tube-bender, this connecting-pipe had to be formed by hand, along with I might say, every other pipework job ever undertaken in this workshop! The best way to ensure accuracy is to form the tube over a template, a photo of which is shown. Now, I wish I had a pound for every time this blower-pipe needed annealing during forming as I'd be at least a fiver better off.

In order to connect the blower pipe to the fittings, one pipe-nipple was of the standard conical type but the other end necessitated one of the flat-headed variety, otherwise, with such a short length of pipe, it would be impossible to assemble without having the smokebox elbow loose. It must be said that I'm not a fan of flat nipples, I much prefer the pointy ones, but sometimes one just has to alter one's preferences.

So there you have it. You may wish to disagree, but in my opinion the end result has produced a neat and tidy blower arrangement, which hopefully will improve the steaming ability over the original design. At a later stage these model-engineering style valve hand-wheels will be changed for a more suitable vintage-looking type.
 

August 16, 2020

Staying with the theme of improving Simplicity's ability to make steam, it was decided to take a closer look at the smokebox draughting arrangement. As many steam devotees will know, this is one of the major factors that can affect steam production. The full size railway companies, both at home and abroad, invested a lot of research into this particular aspect of locomotive design. Whilst I'm not totally familiar with road-steam design, I like to think I have a reasonable understanding of how railway locos function, and so decided to follow draughting rules as applied to rail, after all, they're Stephenson type steam engines, just the same.

Now I have a book, which has proved to be an invaluable source of reference for many years, entitled 'Manual of Model Steam Locomotive Construction', written by the late Martin Evans, a prolific designer of miniature locomotives from O-gauge to 7¼" and just about every other scale and gauge in between. I've also had the pleasure of driving several of his different designs over the years, and none were ever shy on steam; in fact my own Jubilee loco is based on his 'Leander' design, so it would be fair to say he knew his stuff.

The chapter concerning smokeboxes suggests that the blast-nozzle size should be around 1/7 of cylinder bore, which on Simplicity gives an orifice of around 5/32" dia., and a petticoat-pipe choke diameter around that of the cylinder bore. A drawing was now produced of the chimney arrangement as detailed on Simplicity's own drawings. Firstly, steam exit-cones from the blast-nozzle were drawn in: one cone with an included angle of 1 in 3 and the other with 1 in 6, as laid down by Mr.Evans. The 1 in 3 cone should coincide with the choke dia. of the petticoat-pipe and the 1 in 6 with the top of said pipe (or chimney). The chimney and the petticoat-pipe on Simplicity are one and the same item as the blast-nozzle is already in the smokebox roof! Well, the 1 in 3 coincided about half way up the chimney, which is probably OK, but the 1 in 6 is estimated (as the sheet of paper wasn't big enough) as coinciding with the chimney bore just a few metres short of the ionosphere; this surely can't be right - can it?

Included in the box of bits purchased at the beginning of this project was a cored iron casting, flanged at each end, which I had always assumed was nothing to do with Simplicity and had just found it's way into the box. It suddenly dawned that maybe this casting could be a 'chimney-liner', the dimensions certainly suggested such, but yet again, there is no mention of one on Simplicity's drawings, or even included in the list of castings available from the supplier. A photo of this casting is shown standing next to the chimney; although it may look a tad short it, has to sit up the chimney at a set height above the blast nozzle.

A second drawing (shown in the photo) was then produced, only now taking this 'chimney-liner' into account. (NB. No fancy CAD software here, just a sheet of paper, propelling-pencil and 12" rule)! A near perfect set of results ensued and convinced me that this casting was indeed 'meant to be'. The liner bore and choke flare were machined and the flanges turned to a nice snug fit inside the chimney bore, the liner being held in place (it's position determined from the drawing) by a single screw at the top of the chimney, which is conveniently hidden by the chimney-cap. Should I be on completely the wrong tack then the fixing-screw and liner can soon be removed and everything then will revert back to original.

The fact that the liner's outer diameter is reduced between the flanges gave rise to an idea. If slots were provided in the top flange, to allow air to escape, then surely said air will circulate around the cavity twixt liner and chimney, and in so doing help keep the outer surface of the chimney slightly cooler than it would otherwise be (which in turn should be kinder on the paintwork). All of this seems logical to me, but then not having attained a Masters Degree in Thermodynamics, I wouldn't wish to bet my pocket-money on it!

So there it is. In theory all this extra work should be an improvement, but only time will tell. Well that's the last of the exhaust-jobs completed, it's now time to turn attention to other areas.

August 22, 2020

There has been an overwhelming need this week for some light relief, so some minor details have been completed. It's said "a picture paints a thousand words", which is a blessing, as there's not much to actually say about these bits and pieces.

First up is the boiler blow-down valve; a straightforward lathe job comprising a bronze body-casting and stainless steel spindle.

Next come the rear hub-covers. Castings again, yet another lathe job. These will eventually end up being polished, a bit of 'bling' as they say.

And finally, the firehole door opening-chain, which will hopefully save burnt fingers!

August 31, 2020

Far from 'scraping the barrel' this week's update describes scraping the front rollers.

Although roller-scrapers are fitted to just about every road-roller I've ever seen, these are items not fitted to the original Simplicity machines. For those who may not know, the manufacturers, Wallis and Steevens, originally intended these lightweight Simplicity rollers (weighing in at just under three tons) for export to the Commonwealth countries. They were designed primarily for rolling dirt-tracks, not tarmacadam highways, hence their small size and the possible absence of scrapers. To put the weight aspect into perspective, tarmac rollers usually range from six to eight tons. Now, although this model is 3" scale, its physical bulk is more that of a 2" scale, average-sized traction engine, but then as I've been told many times - "size isn't everything".

Over time several full-size machines have been repatriated to the UK and into preservation. Scanning the internet for general pictures of prototypes (with one included here) this particular UK example cropped up, fitted with a front scraper, no doubt in order to cope with muddy British rally fields. Considering the model has a gap between the front-roller and the underside of the fork-casting, varying between 3mm and 5mm only, it was decided to fit a scraper, as per this full-size example, to hopefully prevent the build up of debris clogging said gap; plus it's an extra detail which adds interest to the model overall.

So here it is. Comprising two steel side-members with brass angles bolted between them. Steel angle would have been preferred, but is sadly unavailable in this small size (3/8 x 3/8 x 1/16), unless you know differently of course. Despite looking rather flimsy, the assembly is surprisingly rigid. As for the rear rollers, the full size machine does not appear to have any fitted, but although space is rather limited to get rear scrapers in, I'll give it some thought as the project advances and see what's possible, as it would be nice to 'even things up' and have them included.

As Simplicity progresses, thoughts have occasionally turned to the livery of the finished model. Whilst the green paint-scheme shown here is extremely practical I would prefer something with a bit more flamboyance, maybe a nice salmon pink with lime green and purple lining; as I say, just a thought.

September 6, 2020

Last week I mentioned a possible paint scheme for Simplicity when it's finished. Now whilst down at our superb Delapre track-site this week one of our members was going off in raptures about the merits of grey, it's available in about fifty shades apparently; to be honest I wasn't really paying much attention, but when I get a minute I think I'll Google 'grey and it's fifty shades' just to see if I fancy it or not.

Continuing with the build; this week sees the completion of the reversing-link (gauge-plate) and its die-block (aluminium-bronze), plus lifting-levers and suspension-pivots (mild steel). Those who have ever made a steam engine will need no explanation as to what's involved in their manufacture, therefore I won't give one.

These items are shown both laid out as individual parts and then assembled together into place. Note the reversing-arm, from which the lifting-levers hang; this is the very component that started all these updates earlier this year. In common with a lot of other parts, the ones shown here took many hours to make yet only mere seconds to write about! Nuff said.

September 13, 2020

What is shown this week has to be the most basic reverser going. You'll notice that there are only three positions for the pole: forward, mid-gear and reverse, so 'notching-up' to economise on steam is not an option for Simplicity. So, with expansive working not available, this is the reason for referring last week to what is normally known as the 'expansion-link' as the 'reversing-link'! Having said that, a road-roller spends most of its working life just running backwards and forwards over the same few metres of ground, except perhaps when travelling to the job in the first place, (did they have low-loaders in the 1920's?) so maybe anything more elaborate just isn't necessary.

Back to the model, manufacture did not present any challenges; comprising a cast-iron frame with mild-steel pole and spring-loaded detent components.

In operation, one simply lifts the detent and pushes or pulls the pole for the required direction of travel. It has a very smooth action, with the detent easily clicking into the various seatings (produced with a centre-drill), thus giving a good, positive location; therefore no excuses for not knowing whether it'll be coming or going!

September 21, 2020

Now that the reverser-stand is erected to the spectacle-plate, the natural 'follow-on' is to couple it up to the reversing-arm with the reversing-rod.

The first stage was to hold the reversing-link in the mid-gear position, or put another way, exactly mid-way in the link's slot. As luck would have it a piece of ½" wide material did exactly this and is shown doing exactly that! The next task was to measure the hole-centres between the reversing-arm and the reverser-pole, in it's mid-gear position, which thankfully tallied with the drawing!

A piece of steel was now needed from which to produce the rod. The only material in stock, of a suitable thickness, was way too wide and is shown being held in a milling vice with the required blank being sawn off. I only ever use black hot-rolled steel for flat rods etc., as it is much less likely to distort when machined, unlike bright cold-rolled bar. After deburring, the required holes were drilled and reamed in each end.

The next operation was to waist the rod blank down to finished size by resting it on a couple of parallels and clamping it to an angle-plate, thereafter running a milling cutter along the length as required. The height and the various widths were machined and once these were completed, the slot, which would form the fork at the reversing-arm end, could be cut using a slot-drill.  Removal of the rod from the angle-plate followed and the surplus rod end-material (required for clamping) was then sawn off and the end-radius filed to shape, thus completing the fork. A boss was formed on the reverser-stand end using a rotary table, and that completed the machining operations.

All that was required now was a tart-up with files and emery etc to remove any machining marks, then assembly to place.

It was immensely satisfying to move the pole from forward to reverse with a silky-smooth action, without any binding in the reversing-link components. NICE. Incidentally, I would appreciate it if you don't tell Lady Folwell where her tea-towels keep disappearing to!

September 27, 2020

Now here are a couple of components, the manufacture of which, exercised the little grey cells: the eccentric-rods.

I wanted to machine these rods from solid, as opposed to fabrication, as I did not want to see silver-soldered joints. To add to the complication the forward-rod is straight but the backward-rod has an offset (a photo of the drawing shows this) in order for it to line up with the reversing-link.

If truth be told, I'm no expert when it comes to valve-gear, in fact this is the first model I've built using a Stephenson link motion; but one fact I have discovered is that these rods must have exactly the same length (or hole centres) as each other, in order to function properly. What I am about to attempt to explain may not be the easiest method of production, but it worked for me; so if you do know of a better way then please do not hesitate to keep it to yourself!

In order to accommodate the eccentric-strap bolting-flanges, rod offsets and forked ends, the material blanks were quite 'chunky', with a lot of metal needing to be removed, in places, to give the finished end product. Added to this was a desire to case-harden the pin holes in the forked ends; the drawing does not call for this, but it was regarded as being of benefit considering how these rods, via the reversing-link, tug the slide-valve back and forth.

So the first task was to drill and ream the ⅛" reversing-link pin holes in what were to become the forked ends, edge-finding from the end of the blank and then using co-ordinates to position the holes. This was repeated on both blanks, thus producing an identical pair. The bolting flanges were then milled to finished height and cross-section followed by the machining of the forked ends, with case-hardening following that. The reason the forks were machined at this stage was because the actual rod 'shafts' are quite small in diameter and are turned with a taper from flange to fork. Although this taper is only slight it would have made holding the rods to machine the forks rather awkward, in addition to the finished shafts being rather delicate.

The problem that now presented itself was how to mount the blanks on the lathe between centres in order to turn the shafts, as the end-material (into which lathe-centres would normally have been drilled) had been lost when the forks were machined.  So material had to be inserted back into the forks to enable centre-drilling at this end. This was achieved by milling a couple of tee-sections, a nice sliding fit in the forks, and glueing in place with epoxy. As extra security the tees were then cross-drilled through the link-pin holes and temporary ⅛" pins Loctited in.

It was now a case of clamping the blanks upright to an angle-plate on the mill and, using an edge-finder and co-ordinates yet again, drilling centres in the required positions. That was the forked ends sorted.

Next came the end flanges, which were centre-drilled no problem, These ends needed a spigot, I suppose you'd call it, for the lathe drive-dog to clamp to. The spigot was bolted into 6BA tapped holes in the flanges. This arrangement also necessitated a long and slender lathe-centre to be turned up in-situ to pass through the spigot and engage with the centre-drilling in the flange, I do hope the photos help show all this!

Some of the excess metal was milled away and now the rods were ready for turning the shafts, but I'll continue with that next time.

October 4, 2020

By now a lot of prep-work had been undertaken on the eccentric-rods to get them ready for turning. In view of the delicate nature of the shafts this stage of manufacture was approached with just a little trepidation. Fearing the worst, I consulted my astrological charts, but I needn't have worried as the relevant planets had aligned and all augured well for a successful outcome.

The early turning stages were performed using a HSS tangential turning-tool, an excellent bit of kit which is used for all general turning and facing; but I digress. I've included three photos of the turning process, one of which shows the blank as initially mounted prior to machining. Being the rod with the greater offset it looks all wonky and wrong, but isn't! The 'blueing' that can be seen is the oxide produced when case-hardening the forked ends. Next the rod can be seen fast approaching a circular cross-section, and finally, the last few cuts being undertaken.

With the lathe's top-slide slewed over to the requisite angle, in order to produce the taper, roughing out was very straightforward, if not a little tedious; but as the diameter reduced, and the more delicate the shaft became, the more vibration set in, leaving a truly awful finish, despite a slow spindle speed and a fine feed. The solution was to use a turning tool with greatly increased front clearance and a really sharp tool-point, as can be seen in the photo. Now whilst not being conducive to long tool-life, it did keep the point of contact between tool and job to an absolute minimum, which greatly reduced the problem; here was a situation where I doubt if carbide-inserted tooling would have worked, due to the tip radius. Incidentally, both left and right-handed tools were required.

After turning, the shafts were polished whilst still in the lathe, and ended up looking superb, even if I say so myself.

Anyway, back to the plot. With the machining now complete, all that remained to be done was to drill out the tapped holes in the flange ends clearance on 6BA, warm up the forked ends to soften the adhesive and remove the tees and pins, then bolt the rods to the eccentric straps. The resulting assemblies were then fitted to place, whereupon everything turned over nicely with the valve moving back and forth over the ports and both forward and reverse gear engaging easily; just as it should!

The finished eccentric-rods are shown fitted in place (with the reversing-rod removed for clarity) and, apart from a few split-pins and lock-nuts, that is the motion-work finally complete.

In theory there isn't anything now preventing an air-test, except that is for a loathing of faffing about for hours in an attempt to get the valve-timing somewhere near! So I'm leaving that 'joy' for the time being (no perseverance, that's my problem) and will plod on with construction.

October 12, 2020

And now for something completely different. During the course of a long running project there comes a time, or several times in fact, when I get just a little tired of said project and feel the urge to actually do, 'something completely different'. Being a slave to my urges, I had to give in, and here is the result.

Over the past few years I've been collecting, from E-bay, un-machined castings for a 3½ inch gauge Britannia pacific, one of my favourite classes of locomotive. Many years ago the OS company of Japan produced a Brit in this scale (based on LBSC's drawings) and, upon seeing one at an exhibition, it was love at first sight and I vowed one day I'd make a Brit myself. With there being nothing worse in life than unrequited love I now have very nearly a whole set of castings for LBSC's version, whilst although not being prototypically perfect, is in fact quite close to scale. What I don't have are the tender-horns, so I decided now was the time to fabricate these from steel.

The first operation was to machine up some scabby old black steel-angle into pieces which were square and true, no problemo.

However, what was a problemo was how to braze the gussets in dead square and the correct distance apart. The solution was as follows: taking some pieces of steel, from the off-cuts box, these small blocks were machined to the overall width of the gussets. Next a groove was milled up the middle to bring the gussets to thickness, 1.5mm in this case, the finished gusset blocks being shown in company with the angles.

Now as the truly scrumptious Nigella Lawson might put it: "lightly clamp the parts together and generously smear all over with a creamy flux paste. Place your now sticky pieces in the oven at gas mark 73, or 625°C, and silver-solder together. Now that two have become one, allow to cool, then place in a pan of water and ramp-up the heat to a rolling-boil for approximately twenty minutes, or at the very least, until all the flux-residue has dissolved. Remove from the pan, rinse your bits in clean water and gently rub dry with kitchen-towel".

That's enough of that. Saw off the excess gusset material and carefully file down to suit and there you have it, two perfectly positioned gussets without the need to make fancy locating jigs. The gussets in this case are not 100% scale, but then as I always say "my model - my rules".

The more observant amidst the readership may have counted thirteen completed tender horns when in fact only twelve are actually needed; the reason being that when making 'batches' of components I always make a spare, as Sod's-Law dictates that if I don't, I'll mess one up and I'll wish I had, yet if a spare is made, then I'm almost 100% guaranteed not to need it!

I'm in a bit of a quandary over choosing a number and name, should this Britannia ever get completed. Number 70035 Rudyard Kipling is appealing, after all, he does make exceedingly good locomotives, or maybe 70032 Tennyson, the finest architect this country has ever had, but then possibly 70036 Boadicea, in tribute to the wife. Whatever the final decision may eventually be, that's all for this week, urges satiated, it's time to continue with Simplicity.

October 19, 2020

With Simplicity now having the major 'mechanicals' complete, this would have been an ideal juncture at which to display it on the NSME stand at the Midland Model Engineering Exhibition, but alas, as we all know, this veritable orgy of all things model-engineering had to be cancelled. From my point of view it could well have been a blessing in disguise, for in order to display I would have needed the assistance of someone with a small van; not for the transport of the roller, as it will easily fit into the car, but merely to bring back all the cups, medals, stifficuts and accolades that befits craftsmanship of this magnificence. Ah well, maybe next year.

Now the next component to be made, the water tank, is considered to be important as regards not only its functionality, but also its appearance. The tank is a very prominent feature on the model, and, if not executed neatly, will mar the whole project. In addition, some members will be aware that for thirty years I earned my daily bread as a sheet metalworker/welder/fabricator, until fancying a change and thence driving 44-tonners for Tesco. Therefore if I make a pigs-ear of this tank then I'll never live it down!

As for construction, the tank is made mainly from 18swg brass, having a one-piece outer-shell with an overlapped and riveted seam running along the rear vertical face. Internally there are two strengthening plates/baffles and all are closed off with flanged end-plates, which are also riveted in (flanges inwards), just as the full-size machines.

The tank is mounted by bolting directly to two angle sections, fixed to the front lower edges of the hornplates. Just to make life interesting the top surface of the tank slopes down 27°, to match the underside of the boiler, whilst the tank's own underside lies true to the horizontal, and all bends are radiused. No pressure here then!

Over the years I've used various sheet-metal forming machines, folders, different types of presses, swagers, jogglers et al, so it's fair to say I've come across a few benders in my time. Speaking of benders, Northampton Society of Model Enema's have at least two that I know of; one being a very nice 4ft folder and the other a complimentary matching set of slip-rolls, although sadly neither of these could be utilised in the production of this tank.

So how's it to be done then? Firstly the tank's outer-shell. One method of shaping was to make a wooden former and shape the brass by mallet and hand around that. The pictures show the bandsawn wooden blanks glued and clamped together before final shaping of the radiused corners. Now, when I've built copper boilers in the past, I've always started construction by flanging the necessary plates first, then formed the outer wrapper-sheets to fit said plates. Unlike annealed copper I knew full well that being brass there would be a certain amount of 'spring-back', making the finished dimensions of the shell not 100% guaranteed (not that that matters too much as long as it looks nice) so the thinking was to form the shell first, and only then make a flanging former in order to flange the ends - but back to the block.

After the glue had dried I couldn't resist wedging the timber block under the boiler, just to get an impression of how it would look, as you can see here. Wooden block finally shaped, smoothed and completed it was time to bend some brass, but it soon became apparent that this method of forming was not going to work! The bends were 'vague', to say the least, and the spring-back was horrendous, despite the sheet being the half-hard grade. I daren't show a photo of this aborted attempt, it would keep you awake at night! You might think, "anneal the sheet", but with a blank measuring 11.5" x 24", and only a gas-torch to do it with, the distortion would have been unacceptable, so that was the end of that. So, despite having the benefit of an excellent apprenticeship, and thirty years experience, this venture has proved a complete waste of effort and expense, time and timber. Maybe one is not as magnificent as one likes to think!

Despite this setback, and never having been one to give up at the first hurdle, a different way of forming the shell now has to be found, and as they say in Yorkshire "where there's wood there's brass", or hopefully there will be! I do have one idea though, which may or may not work, and if it doesn't then I'll order a skip, dump the workshop contents in it and take up kick-boxing as a hobby.

In conclusion I can only quote that great Shakespearean actor, Arnold Schwarzenegger, and say  - "I'LL BE BACK".

October 25, 2020

I've already touched on the method of forming radius bends that will now be used, when the side-guards were described in an earlier update. It involves the use of the small fly-press and home-made tooling, comprising a round bar pushing the metal down into a gap, a system used extensively in the trade for one-offs and low volume production. For the bottom tool I fortunately had a 'chunky' piece of steel in stock, into which was milled a groove the same width as the top-bar diameter, 30mm in this instance. This is slightly larger than specified on the drawings but was used for the following reason - rigidity. As you can see from the photos, the ends of this bar are unsupported, which can lead to flexing. This in turn can lead to a perfect radius being formed at the centre of the tool but then tapering out to a larger and less defined radius at the ends, as the bar springs away from the job, so obviously, the larger the bar's diameter then the stiffer it is. The fear of a tapered radius was just one reason why I didn't use this method in the first instance.

In the event, my fears were unfounded as the bar performed perfectly. You will notice that the length required (11.5") is right at the very limit of the fly-press bed capacity, witness the T-nut poking out of the slot, and although for safety reasons none of us should ever have our nuts sticking out, sometimes it just can't be avoided.

As will now be realised, this method of bending prevents the tank-shell being formed in one piece, plus two tank-halves (as they will now have to be) means two joints instead of the intended one (yet another reason why this method was initially considered undesirable). Now a decision had to be made, what type of joints to adopt? Well, I haven't got where I am today without having to make serious decisions, the final decision being to abandon any overlaps and go for butt-joints. I'm not keen on overlaps, even though they allow for slight inaccuracies, as they always look rather amateurish to me. My model - my rules, yet again.

I'd like to welcome you now to the world of precision bending. With the top tank-half having the 27° slope, it follows that this top sloping face will be longer than the bottom face of the horizontal lower tank-half. This in turn means the distance between the bends will differ between the top and bottom half-panels, but by how much? If not bent in exactly the right places the two panels will not match each other in overall width to give perfect inline butt-joints. In addition the joints are to occur on the centre-line of both vertical faces, so what length do you make the panel blanks (again, both will be different) to give this result?

Well, the answer is surprisingly straightforward - a test-piece. Starting with a narrow strip of brass of known length (preferably a bit longer than required) and the same gauge and grade as the panels to be produced, a guesstimate is made as to where to set the back-stops on the tool. The stops can be seen clamped to angles which are bolted to the rear of the press-tool, and all settings recorded. After bending, the test-piece is measured, both to determine how wide/narrow it is over all the bends and how short/long it is over both vertical faces. A few simple sums will show at which positions (or distance from the tool centre-line) to reset the stops, and knowing how long the test piece was initially, how long to make the actual blank overall. Just as a double check the test-piece was flattened, trimmed to the newly calculated length, then re-bent using the newly calculated stop positions, et voila, a perfectly dimensioned test-piece. All that remained to be done now was to trim the actual tank half-panel blank to length and bend up using the new stop positions. Unfortunately though, this whole process had to be repeated for the second half-panel due to the difference in length and bend-angles between top and bottom tank-halves, as mentioned earlier.

You can see the finished half-panels held together with grips, plus the beautiful sight of both vertical faces coming together both inline and straight, plus the joints coinciding smack on the centre-line. I've also shown the two half-panels separated and alongside one of the test-pieces.

Phew, I can now cancel that skip and I'll sleep well tonight!

 

November 1, 2020

Now that the two tank-halves have been formed they now have to be riveted together. If care is not taken when riveting, then the resulting joint can go pear-shaped in several ways. The most common faux-pas is drilling a line of rivets that are not evenly spaced and/or not in line, and when one or indeed several rivets 'break-ranks' it stands out like a sore thumb. Another problem can be distortion, due to excessive hammering stretching the metal and resulting in a curved panel, the rectification of which can sometimes prove impossible. How many of us have ever looked down the side of a full-size, fully riveted, locomotive tender and noticed all the ripples? Some have more waves than the North Atlantic! What follows now is how these tank joints were executed, resulting in flat and straight surfaces.

Along with many other builders, I find it's always best to drill a long line of holes using the milling machine. Pictured here, you can see a convoluted set-up using two angle plates, due to the shape of the panel. Clamped along the back is a bar, against which the panel joint-edge is kept pushed. At the RH end is a small block against which the panel end is also kept pushed. It's now a simple case of indexing the table along the required hole-centre distance and thus producing a perfectly straight and evenly spaced line of holes.

As with any riveted butt-joint there has to be a lap-strip spanning the join. The rear vertical face-joint benefits from having short, and therefore stiff, edges, and a simple flat piece of brass will suffice. The front joint-face, being much taller, is less stiff and a small channel was folded up to increase rigidity. Obviously the lap-strips were clamped to one tank-half and drilled through and deburred ready to accept the rivets. As has already been mentioned, there is no need to whack the living daylights out of the rivet shanks; this is a miniature tank, not the hull of the SS Great Britain! The rivets are only there to hold everything together prior to sweating the joints. The photos show these lap-strips fixed to one of the tank-halves.

The pictures also show several angle-sections fixed to the tank-halves. The outboard angles perform several functions: they stiffen up the panel, they also thicken the material where, at a later stage, 6BA tapped fixing holes for the coal bunkers will be, and lastly they act as 'stops' for the raw edges of the flanged end-plates to push up against. This ensures the end-plates are positioned perfectly when drilling for their rivets. The inboard angles again stiffen the panel, but also form the mounting surface for the baffles, which are to be 'nutted' in place, hence the studs that can be seen. There is a specific reason for this method of fixing which will become apparent as the build progresses. The inboard angles in the upper tank-half are ⅛" thick, as they are where the M4 tank fixing-bolts will come. All of these angles were fixed to the tank-halves using 10BA countersunk screws (the only brass screws in stock) purely to hold them in place ready for soldering.

Another decision had to be made at this stage regarding the appearance of the front joint; this being whether to use countersunk-head rivets, fit then file flush to try and hide it, or use snap-head rivets and make a feature of the joint, even if it isn't true to prototype. Well the latter option was chosen, it just looks nice!

 

November 7, 2020

Dearly Beloved. You are viewing this update today to witness the joining together of this upper and this lower tank half. If anyone knows of any lawful impediment why these two halves should not be joined together in metallic matrimony well tough - it's too late - because they now have been. But before this union took place I thought I'd make up the two baffles. Now I'd had some brass off-cuts, which although too short for the baffles, were pretty much the required width, so they were riveted and silver-soldered together. This may seem a bit 'belt and braces' but then that which Richard hath joined together let no man put asunder! A tank assembly 'dry run' was then undertaken, before the final riveting, just to make sure everything fitted. The baffles were then removed and the fixing-holes slotted slightly to give some adjustment on the studs; the reason for which I will now explain.

When bending tank-halves, such as these, it is possible to inadvertently build in a 'twist', and Simplicity is no exception. This can be due to a variety of factors: the tank-blanks not exactly square, back-stops not set exactly the same distance from the centre-line of the bending tool, or even a variation in the bend along its length. With the two front edges of the tank-halves perfectly aligned you can clearly see in one photo how the rear joint edges are approximately 5mm out of alignment. 'Tis but a simple matter to just slide these edges along and into alignment and clamp; and in so doing the top and bottom flat faces of the tank twist to take up the error. By 'twist' I mean that the top surface of the tank will not sit flat, and rocks against the tank mounting angles, plus the bottom horizontal surface lifts up on one side and dips down on the other, but all is not lost yet.

Even with the tank-shell twisted, the upper tank-half was temporarily bolted (or betrothed) to the lower half with 8BA screws and the remaining 3/32" dia. rivet holes drilled and then riveted. The resulting assembly then had all the internal joints sweated over with soft-solder, thus joining the two tank-halves together permanently. After a thorough washing to remove any flux, the tank was then positioned in place under the mounting angles and the bolting holes marked through onto the top surface of the tank.

In the very first update concerning this tank build, I had berated the original wooden forming-block for being a total waste of time, but look at it now. Resting on the mill table it made the perfect support on which to sit the tank, in order to present the sloping surfaces horizontally to the drill-bit; so it doth appear that some clouds really do have a silver lining! Fixing holes drilled and tapped the tank was presented back up to the mounting angles and the M4 fixing-bolts fitted and tightened. With the tank still having slight flexibility, this bolting action has 're-twisted' the tank true and flat to the mounting angles, and the subsequent fitting and tightening of the baffles has the effect of permanently locking the tank assembly in this 'true and flat' position. Job done.

So then, after all that, all's well that ends well, and yet again, I shall sleep soundly in my bed tonight.

November 15, 2020

Before going any further I'd like to describe the water-tank bushes. The ones shown on the drawings are of the typical female threaded, flat-headed and square-shouldered variety, meaning they obviously have to be positioned on a flat surface. This is all very well but positioned on the flat also means they would only deliver water to around 25mm of the bottom of the tank. The type of bush I am about to describe, although being a lot more work, can deliver water to around 5mm of the bottom. I know that's only an extra 20mm, but then who wouldn't want an extra 20mm, I know I would as after all, it might mean making it to the next watering-hole - when out on a run - or not!

As these bushes were to be fitted on the radius of the tank bends, they needed to be 'scalloped' to suit, in order to provide a seating on said radius. It would save a lot of work simply to use a plain parallel bush, poke it in the hole, then solder around it, but this leaves the joint rather weak, plus how do you hold it in place for soldering? Far better to have a saddle joint, which the scallop provides, then solder around that. The scallop was produced on the milling machine using the boring-head set to the bend-radius and offset from the centre of the bush to suit, as shown.

The radiused tank-bends also mean that the bush-holes in the tank cannot be produced with a standard twist-drill. A slot-drill was used initially, then because Sod's Law dictates 'you will not possess a cutter of the correct size', the holes were skimmed out to finished diameter using a boring-tool, which is also shown.

Now, not owning a CNC machining-centre it was impossible to turn, integrally, the parallel section that pokes into the tank, which is needed mainly to locate the bush on the tank body for silver-soldering.  So a parallel brass section was silver-soldered (using a high temperature grade) right through the body of the scalloped section and protrudes into thin air the other end, as can be seen. Care had to be taken not to allow the silver-solder to run down inside the fitting and form a fillet on the scallop as this would upset the seating on the tank; so the brass section was made a tight fit in the body and the deep countersink provides space for solder to form a joint. This parallel section also provided a means of holding the soldered assemblies in the lathe, in order to machine the male outer ends for the pipe connections.  Incidentally, the bush with the 'dipper tube' will be the pick-up pipe for the mechanically driven feed-water pump and lay, just a touch, off the tank bottom. It's had to be done this way as both the pump-feed and pump-bypass bushes will be mounted vertically (again, on the radius) on the tank's upper surface. The other bushes, mounted on the tanks lower regions, are for injector feed, hand-pump feed and a drain.

So that's it for this week. Next time will see us leave the water-tank, just for a short while, as there's something else that needs to be done. Oh wot fun!

 

November 22, 2020

Before going on to produce the flanged tank end-plates, I wanted to make and fit the coal-bunkers, not only to see if the fitting of such introduced any distortion to the tank top surface, but also to deburr the fixing holes and remove any swarf. As you can see there is no great complication involved with the manufacture of these, but they do have to look nice and tidy!

The bunkers are simply two channels, which were folded up from rectangular blanks, before producing the sloping bottom-edges which fit to the water-tank's top surface. The bunker fixing flanges are shown on the drawings as being bent tabs integral with the main bodies, but it's far more straightforward to fold some separate angles and rivet these on once the bottom edges are finished. Also doing it this way makes it far easier to get a flat and gap-free fit.

The top beadings are ¼" wide, and, just as with the side-guards featured in an earlier update, are fixed with 1/16" rivets gently peened into shallow countersinks in the bead. The peened rivet shanks were then carefully filed flush, as can be seen in the 'before and after' shot (the rivets holding the fixing angles on had already been smoothed off).

You can see the finished bunkers bolted to the tank and thankfully no distortion had occurred, due to taking care in keeping the bunker bottom edges flat. You may also notice the pilot holes drilled in the tank ends ready for the rivets that will hold the flanged end-plates, the production of which moves ever closer.

November 29, 2020

Due to a male-modelling commitment this week, I've sadly no progression on Simplicity's water tank to report. But, determined as I am to help fellow members (and gain an extra week to actually get something made) I thought instead I'd pass on a couple of workshop tips, which some of you may already know about, yet some may not.

I cannot lay claim to either of these 'aids' as sadly I'm not that clever. The first is a means of tapping holes, by hand, dead square to any surface using a guide. You will see that the guide is simply a piece of round bar turned down to provide a grip leaving a flange at the bottom which is kept pushed against the surface requiring the thread. The flange end is faced square in the lathe and then a hole is drilled right through the guide the same diameter (a few thou larger doesn't matter) as the plain shank of the relevant tap and away you go. They take just a few minutes to make yet repay the time taken over and over again.

One photo shows the tank top-surface being tapped, which remember is 27° to the bench when resting on its base, and another shows tapping underway on the vertical surface of a hornplate. The screws are shown fitted and note how they are perfectly square in both planes to the vertical surface. Also note the tapping guide which has a flat machined on it to miss any obstacles, in this case the tank mounting angle. Another advantage of using a guide, rather than tapping freehand, is that they make tap-breakage much less likely, particularly in the small sizes we often use, which makes them worth making purely for that fact alone!

Next up is an old Indian trick, shown to me not surprisingly by an old Indian, Ramesh, whom I had the pleasure of working with way back. A master craftsman and good old boy he is sadly no longer with us but his memory lives on, no more so than when I receive regular phone calls from 'Clive' in Mumbai (their accents being identical). Clive always offers to be of assistance in making a claim regarding my recent accident. Well I've racked my brain and the only 'recent accident' I can recall is when the lathe tool dug in and completely wrecked Simplicity's exhaust-pipe fabrication. So I've referred Clive to the relevant Simplicity update where he can find full details. So far I've heard nothing back. Incidentally, there was a Britannia locomotive, number 70040, named 'Clive of India'; it couldn't be, could it? But I digress, so back to Ramesh's tip.

When it came to fitting the coal-bunker fixing screws, through the 18swg fixing angles and into the tank's top, the lower screws were impossible to get at with a box-spanner, making 'starting' the thread extremely difficult. The answer is to turn a 'pip' on the end of the screw having a diameter just less than the core diameter of the tapped hole. The pip drops into the hole and holding the screw approximately vertical, with whatever comes easily to hand (a small electricians screwdriver in this instance) the screw could be started first time, every time, with an open-ended spanner. No naughty words and no evicting Teddy from his cot. May your Gods bless you Ramesh!

As I said at the start, some may already know of these dodges; but then if only one model-engineer out there in cyber-space has learned something useful today, then my life will not have been lived in vain! Feel the love everyone - feel the love.

December 7, 2020

At last I have some workshop time to myself and can now get on with the production of the tank end-plates. The first requirement though is a flanging-former over which to 'bash-the-brass'. Anyone who has ever built a boiler will know all about making formers, so if you don't want to know the result - then look away now!

In order to determine the shape required for the former, a piece of 3mm steel was carefully cut, filed and fitted into the end of the tank; we don't want any gaps! Once happy with the fit an allowance for the flange thickness had to be made (1.2mm or 0.048" depending on which way you swing) and this amount was removed all round. We now have the shape of our actual flanging-former.

From experience it has to be said that there is no better material for flanging-formers than steel (or aluminium if you must) especially when working brass. I was now down to my very last piece of steel plate, 10mm thick in this instance, and Sod's Law reared it's ugly head yet again by dictating "The only piece you have will be 30mm short of what you actually require!" Fortunately though the steel blank being rectangular, and the tank being a (get this) trapezoidal quadrilateral, a triangular piece had to be cut off the blank. This off-cut could now be welded onto the end of the main portion to make up the deficit.

In order to get full weld penetration of the 10mm thick plate the joint edges were 'vee'd' each side 5mm deep using an angle-grinder. This is done to allow an equal amount of weld to be performed on each side, for if welded on just one side only the former would curl up due to contraction of the weld metal. Welding each side equally tends to even out this contraction/distortion and helps keep the job flat. The very last thing you need is a curved end-plate! Incidentally, all plain lap-joints on steel boilers are made by veeing out full depth before welding, or at least they should be!

Welding completed, the upstanding weld-metal was linished off using a flexible disc on the trusty angle-grinder to leave what you see here. The profile was transferred from the 3mm thick template and the flanging-former hacked out to size using bandsaw and files etc. There was a very slight bow in the flanging-former left from welding, so it was lightly skimmed on the mill to achieve perfect flatness. Looking at the finished article the un-informed would never know it was a 'cut and shut' job. A 3mm radius was produced all around the edges of the former and now, at last, the end-plates are in sight!

December 13, 2020

Not only did this week herald my 65th birthday, but also production of the tank end-plates. It's rather sobering to think that when I joined NSME I was a mere 32. Scary! Anyway, moving swiftly on, it's flange time. Two brass blanks were cut, 10mm larger all round than the former, to allow for the flange, and evenly positioned between the former and the 3mm steel piece that was used as a template and now becomes the clamping plate. Being 18swg and half-hard grade there was no need to anneal the brass. The flange was then gently formed, a bit at a time, by knocking over the former. The straight sections bend up easily, but the corners require a bit more care.

When forming the corners the metal starts to pucker-up and form 'crests'; this is because the metal has to shrink in order to follow the curve - and it doesn't want to! So the technique is to knock down each crest as it appears in a slow and controlled manner. If you go at it as per a bull in a china-shop you get the result shown here in one of the photos, with the puckering getting worse and worse until eventually the metal overlaps itself (because it hasn't had a chance to shrink) and the job is well and truly pucked. Compare this ghastly mess with the other photo which shows the corner very nearly finished and looking much more civilised. Before anyone thinks that Yours Truly loses all self-control when let loose with a hammer, then let me assure you that this state of affairs was done deliberately purely to illustrate a point and stopped before the job was irretrievable! When the flanging is complete you get a uniform flange hugging the former tightly.

Now, the depth of flange actually required was 8mm, not 10mm, so the flanging-former was skimmed down to 8mm thickness by mounting it on an old magnetic chuck, which had been salvaged from a worn out surface-grinder many moons ago. This magnetic table is ideal for holding flat ferrous objects as there are no clamps to hinder machining. Another plus is that being magnetic the swarf doesn't fly everywhere.

All that remained to be done now was to place the flanged end-plates back onto the now thinner former and rip down the surplus brass until level with the steel using a file; an arm-aching job! The flange was required to have an even depth all round as the raw edges will butt up against the 'stop' angles fixed inside the shell, thus giving the end-plates a uniform protrusion from the main-shell.

So that's it, with flanging complete both ends are now ready for fitting. I forgot to mention the fact that the end-plates are handed - obviously! Simply turn the former over to flange the opposite hand; another reason to bend the tank half-shells accurately in the first instance or the tank cross-sections could vary each end and you'll need two different formers!

December 21, 2020

Since last week's update the end-plates have been fitted and soft-soldered in. The rivets are not actually acting as rivets, more as per copper dowel-pins, as it was impossible to get inside the tank to peen the rivet shanks over. The rivet holes were drilled, deburred and swarf removed, ends refitted and the rivets poked in, which then became soldered in as I sweated around the flanges. Considering this tank is 3 inch scale then even the full-size tank must have been a tight squeeze to get inside with a hammer. I can only think that the manufacturers must have used Santa's elves, who being unemployed from late December through to early December, were sent on a Government Retraining Scheme, graduating as riveters-mates!

You'll also notice that the tank access-hole cover-plates are now fitted. The drawing describes these plates as 'optional', but we've come this far, so what's a few more hours? They are purely for effect as there are no actual apertures requiring covering; but then as Confucius himself once said "Details maketh Model". Well what he actually said was "xijie shi moxing" but you get the picture. So, it could be argued that this water-tank, with it's rivets not being 'riveted' and cover plates not actually covering any holes, is a sham, a facade, or as Lady Folwell puts it - "all brown boots and no knickers". But be that as it may I'm delighted with it and regard the end result as TANKTASTIC!

A functional detail that can also be seen is the tank filler-tube and cap. When viewed side-on it is perfectly vertical, but sadly, when viewed from the front, it tilts very slightly to the left. So before being criticised for this faux-pas let me just say the following:

As a much younger, yet bewildered man, I felt compelled to embark on a journey to seek out the 'meaning of life', with the ultimate aim of finding my true destiny. On my travels I happened across a Buddhist Retreat, deep in the foothills of Lincolnshire. Whilst there I noticed the devout craftsmen would deliberately build a small imperfection into their otherwise perfect creations. Upon enquiring as to why, I was told it was a gesture to the Almighty that they, as mere mortals, could never attain His state of perfection and hoped for His blessing in return. So I'm hoping this 'Leaning Filler of Pisa' will be seen as my appeasement to the Main-Man, the only difference being 'mine' was not intentional!

Another little known fact is that I very nearly joined these good folk, finding the Buddhist philosophy towards life most appealing. After filling in the application form I turned it over to read the Terms & Conditions. There were only three stipulations: (1) SHAVED HEAD - Not a problem as I was 80% there already. (2) UNIFORM TO BE WORN AT ALL TIMES - Again, not a problem; in fact the skimpy orange loin-cloth complimented my natural skin-tone perfectly. (3) VEGAN DIET - Well, I just couldn't bear the thought of never again sinking my teeth into a quarter-pounder with cheese, which left me no option but to leave; so I left.

The sad outcome is that my quest for 'true-enlightenment' ever continues, but the good news is that so will these Simplicity updates. Merry Christmas everyone.

December 27, 2020

Now that the water-tank had been fitted it was possible to see exactly how much space was available in which to fit scrapers for the rear rollers. As you have probably gathered, room was rather tight to say the least, and with no details to go on a 'Self-Evolutionary Design Ethos' was employed - that's sales brochure speak for "I made it up as I went along!"

The first consideration was how to present the scraper-blades to the rollers. Scanning the internet for inspiration (how did we all manage before the cyber-encyclopedia) it showed different manufacturers of full-size machines had different ideas on how to do it, varying from simple to complex. Being simple myself this was the option chosen. Four 1.5mm thick steel channels were folded up, onto which the blades would be bolted through slotted holes in order to adjust the running clearance. These channels would be brazed to 3mm thick vertical plates, which in turn would be bolted to the hornplates. It all seemed rather flimsy so gusset plates were added twixt channels and bolting-plates, as seen. In addition it was realised that there would be little strength in the vertical plane with the assemblies getting bent upwards a strong possibility. To help counter this possibility, the vertical plates were drilled toward their lower edges and would be fitted with stay-rods running right across the chassis - thus tying the opposite plates together.

Now, making jigs and fixtures has never been my favourite pastime, so a simple 'lash-up' was concocted to hold the parts together squarely for brazing. The more experienced fabricator will probably look at the photo and think it would be quite easy to braze the channel and gusset to the packing strip, requiring an angle-grinder to remove said strip. Well let me assure you, a highly experienced, nay gifted metalworker such as myself, would never allow such a catastrophe to befall him. As can be seen, the resultant fabrications looked dreadful immediately after brazing, but with determination and more than a little TLC, they were made to look a lot more presentable. Before leaving the subject of silver-soldering/brazing I really must stress the importance of performing such in a well ventilated area. Although Cadmium is no longer added to silver-brazing alloys, the flux fumes are still quite noxious. Inhalation of such can leave you with a thumping headache and in extreme cases prolonged inhalation can lead to complete unconsc......


Where am I? Oh yes. Anyway that's all for this week, I'm off for Botox and a jolly good moisturising ready for the New Year - these youthful good looks are not maintained without a little assistance! Let us all hope that life eventually gets better during 2021. Happy New Year everyone.

January 3, 2021

Looking again at the scraper-blade mounting channels a change of heart occurred and it was decided to shorten them to bring these to the same overall width as the water tank. These channels had already been mounted onto the roller at the same height from the 'road' as the tank base-line. This was done in order to make it look as if at least a modicum of thought had gone into the design! The shortened and drilled channels are shown.

The next items to be made were the scraper blades. As can be seen they are simply 1.5mm steel plates with a 'set' bent into the working edge to provide greater stiffness than would be otherwise. They have been tapered off just because they look better than being simply rectangular.

If you look at the photo of the back end of the roller, showing the rearward scraper assemblies, the transverse tie-bar can be seen nutted in position. The rearward extension and drilling of the vertical bolting-plates was necessary in order to throw the tie-bar clear of the handbrake mechanism. The forward scraper channels, behind the water tank and having no such obstruction to contend with, were drilled and fitted with their tie-bar on the centre-line of the channel. Despite only being 5mm dia these tie-bars have stiffened up the scraper assemblies remarkably well.

So that's the scrapers done. Although a fair amount of work I think they were worth the effort. Next week I'll be attempting to rectify a problem!

January 10, 2021

Earlier in the build the steering mechanism was erected and a tight-spot experienced as the steering-wheel was turned. This was put down at the time to flexing in the ¼" dia. steering-shaft. So, a support bracket was fabricated up and fitted with a cast-iron bearing bush. This was then bolted through the side-guard and into one of the canopy uprights. Although not detailed on the drawings it was noticed that several full-size machines have these supports fitted, you can just make one out on the full size machine shown; and at the risk of sounding like a record it's the black bracket bolted through the side-guard and into one of the canopy uprights! This suggests that flexing of the steering shaft was a common problem.

Well it can now be reported, and without fear of contradiction, that all this 'effort and dedication' resulted in not one iota of improvement whatsoever. Careful observation of the worm and gear-quadrant showed the 'mesh' of the gears to be rather tight. With nothing to lose the bolt holes, through which the front steering-shaft bearing is held to the chassis, were slotted slightly with a needle file and the assembly erected again, only this time with the gear mesh eased just a few thou. Result? No more tight spot! Let joy be unconfined.

By rights there should not have been a tight-spot at all.  Yet more 'careful observation' did reveal a small amount of eccentricity in the steering-worm, hence the problem, and this despite boring the worm by holding it in freshly machined soft-jaws in the lathe chuck - sometimes you just can't win!

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