Making wheelsets for split-framed OO9 locos.

I've been experimenting with making up wheelsets for OO9 locos. My aim is to be able to scratchbuild inside framed locos, using split frame pick-ups as per the old Saltford Models kits.
For split frame collection to work you need solid metal wheels fitted with stub axles, which locate in an insulated bush. I don't have a form tool for producing wheel profiles, and to turn wheelsets with a form tool you will need a very rigid machine with a lot more power than my Unimat has. So my solution is to use the tyres from Parkside Dundas wagon wheels pressed onto turned brass centres.
For this experiment I used Parkside's 7mm N gauge wagon wheels. To start I seperated the tyres from their plastic centres. Then, after measuring the inside dia. of the tyre (6.36mm) I turned a length of 7mm dia. brass approx. .05mm oversize (6.41 - 6.43mm), the width of the tyre plus the width of my parting off tool. A .5mm long x 2.5mm dia. step was turned onto the end as well, copying the plastic centre. After drilling a 1.4mm hole for the axle the tyre could be pressed onto the new centre;

The parting off tool was positioned by lightly touching the tool on the flange back face, then the saddle could be locked and the wheel parted off;

Here's one brass centered wheel next to an untouched Parkside example;

Stub axles are 1.5mm steel. To fit the axles I opened out the 1.4mm holes with a 5-sided cutting broach until the axle would just start to fit. Then the axles could be pressed in place on the lathe. I did try drilling one wheel 1.5mm, but the hole turned out slightly oversize.

Axle muffs are Acetal, turned down to 1/8" (to suit readily available gears) and drilled first to 1.4mm then to 1.5mm. One was parted off at 7.5mm long, for OO9, and the other at 4.5mm, for OO6 (18" gauge);

I don't have a use for these two axles, these are just test pieces.

Spindle speeds for brass were 2000rpm for turning and drilling, 365rpm for parting off. For Acetal the machine was set at 1600rpm for all operations. All work was cut dry.

Paul.

Making new flycranks for a Saltford Peckett.

As I've stated before, there's a problem with the Saltford Models Peckett in that the flycranks are oversize compared to the wheels and foul points and inset track. The simple solution would be to take a file to the outside of the cranks, but I decided to make up some new cranks on the Unimat.

Both cranks were made together at the same time. I turned some 5mm dia. brass down to 4.5mm dia (the wheels being 5.2mm dia.)., 6mm long (width of crank + parting off tool x 2) and drilled a 1.5mm hole to depth. The Saltford kit use 1/16" axles, I don't own a suitable drill so I'll open the cranks out with a cutting broach to suit before fitting.

Then the machine was set up as a drill press with the work held in a 3 jaw chuck mounted on the saddle. A 1mm dia. crankpin hole could then be drilled, this was positioned by eye as it doesn't need to be a precision job (not this time anyway);

To shape the cranks I held the job in the 3 jaw chuck mounted on the tailstock. I could have machined the flats, but I don't have a milling cutter handy so I just used a file and judged the shape by eye;

The cranks could then be parted off;

And here are the two cranks along with a Saltford cast crank;

Now they need some light fettling, but I couldn't resist trying one on the loco for size (remember that the loco is essentially a 2-2-0, therefore only one crank per side needed);

Crankpins will be made from 1mm rod, and the con. rods held in place with small sections of clear plastic sleeve (supplied with the kit). Unless I try to be clever...

Now I need to make another pair for my red Peckett.

Spindle speeds for turning and drilling were set at 2000rpm, and at 365rpm for parting off. Work was cut dry.

Paul.

Grounded van bodies 4.

Here's a pair that I spotted near Walton Lees Farm, Hungerhill Lane, west of Chesterfield (SK325673);

I'm not going to attempt to identify these two! Although I imagine the rearmost shell was once plywood sided.

Paul.

A couple of accessories for my Unimat SL.

I've bought a couple of usefull accessories for my Unimat SL.

First up, a carriage stop. This simply clamps across the bed and provides a positive stop for the saddle, helpfull when turning to a shoulder (chuck removed for clarity);

From Mundford Machine Tooling through Ebay.

Secondly, a threaded T slot adaptor. This is threaded  M12x1, the same as the spindle and tailstock, and allows you to mount a lathe chuck, drill chuck, faceplate etc. to the saddle when using the machine as a mill/drill;

Obviously being able to mount a chuck on the saddle will be usefull for holding anything round for further machining, drilling a hole offset from the centre for example. The usefullness of this for model railway work should be fairly evident.

Paul.

Saltford Pecketts.

My favourite ever OO9 loco kit is the Saltford Models 'Small Saddle Tank Engine', sadly no longer available. This was sold as a 'Bagnall-Peckett Type', although its definitely leaning more towards Peckett than Bagnall. It's a little basic compared to some of the more modern OO9 kits now available, but I feel that it has a great deal of charactor. I own 3 of these, one built and finished, one part finished (just needs painting and final detailing) and one still sealed in its packaging.

Like the Simplex this uses the split frame pick up system. The frames and bodywork are whitemetal whilst the footplate and buffer beams are, for insulating purposes, plasticard. Whitemetal is also used for the connecting rods, cylinders and flycranks. No coupling rods are supplied, and drive is to the rear wheels only, making it in reality a 2-2-0!

This one is my original, and my favourite kit built loco;

Its built as Brian Clarke intended and runs nicely.

My second loco has been slightly modified, it sports a better motor (5 pole LH17 instead of the supplied cheapo 3 pole) fitted with a custom turned flywheel (I was working in a machine shop at the time that I built this), brass axle bearings (the axles usually run straight in the w/m frames), a lubricator fitted onto the chimney (another Saltford casting), springs above the front axle (Chivers w/m castings), and extra pipework under the tank sides;

There's still a fair amount of work to do before its finished.

The con rods on these locos have a cut down split pin on the piston end, which slides along a fixed 'piston' rod glued into the cylinder. There's no attempt at even cosmetic slidebars. Despite the crudeness (or because of it?) watching it trundle along is a joy.

Even the instuctions had a certain charm, here's the exploded view;

But, there is a fault with the kit in that the flycranks are too big, meaning that they are in fact larger than the wheels, a problem on pointwork and inset track. However, it is a proper outside framed loco, and like all of Saltford's range came as a complete kit.

Paul.

Turning a funnel for a OO9 Krauss.

James Hilton's building an 0-6-0 Krauss for his OO9 Romanian forestry project. As I was looking for a nice little turning project I volunteered to turn him a funnel, the other boiler fittings James sourced from a Langley kit. The funnel has a tapered spark arrestor on the top, which made it an interesting little job...

I used 7/16" dia. brass, which is approximately 11.1mm, perfect as the widest part of the funnel needed to be 11mm. I cut a piece slightly overlength, then turned the parallel lower section (4mm dia.) before turning a 2mm dia. spigot on the bottom to locate in the smokebox;

To turn the lower part of the taper I swivelled the headstock around (there's no compound slide in the SL), and to get somewhere close to the correct angle I made a twice full size drawing of the spark arrestor, cut out the profile, and used the template to help set the headstock angle. Not very technical, and 'proper' model engineers will cringe, but the angle was close enough. I had to adjust the angle whilst turning the taper, but I ended up with the correct taper (or close enough anyway) in the end.
I had to use a pointed tool, and the original smaller toolpost rather than the 4 position post that I usually use, as the clearences are limited due to the angle of the headstock;

Again 'proper' engineers would cringe, look at the amount of overhang on the turning tool. Sometimes you just ain't going to get the perfect set-up!

To turn the upper part I held the job on the 4mm dia., then turned the short (.5mm long) top parallel section and faced the job to length. Then again it was a case setting the headstock angle and turning the top of the spark arrestor;

After setting the headstock square again I centre drilled the end, then drilled the upper section out to 4mm, starting with a 2mm drill then working up in .5mm steps, so as not to put too much strain on the turned section being held in the chuck.
Here's the finished job;

Spindle speeds were set at 1600/2000 rpm, and the work was cut dry.

Paul.

The Industrial Tramways of the Vale of Llangollen.

This is quite a slim volume, giving an overview of the industrial tramways, mainly quarry related, around Llangollen. Industries covered are mostly limestone and slate, but there is also coverage of wartime forestry work at Vivod and brickworks at Penybont. The systems described are mostly horse worked narrow gauge lines or plateways linking high level quarries with the Llangollen Canal. Of particular interest is the Deeside and Moelferna Quarry system, which used a mixture of conventional flat bottomed rail and wooden way (wooden rails topped with strips of iron), featured on the cover.

An interesting little book in the usual Oakwood style. I found it usefull to have an Ordnance Survey map handy when reading it, if only to get a feeling of the lay of the land described.

The Industrial Tramways of the Vale of LLangollen, J.R. Thomas & D.W. Southern, Oakwood Press ISBN 0853617273.

Paul.

More messing with my Unimat SL.

One problem that I've noted is that the drill chuck runs out of true when fitted to the headstock spindle, which would cause a lot of trouble when using the machine as a mill/drill. The back face of the chuck needs to butt up against the shoulder of the spindle for it to run true, but the thread inside the chuck body bottoms out onto the spindle thread before the back face meets the shoulder, leaving a gap;

The proper solution would be to machine away part of the chuck thread, but I decided instead to turn a brass collar to sit between chuck and spindle shoulder. Mounting the drill chuck in a 3 jaw is possible, but I'd need to clock it up (make sure that it runs true using a dial test indicator (DTI)) and all of my DTIs are down at my Mum's house in Bedfordshire along with a lot of other usefull tools. And anyway, I fancied making something...

I turned a spacer from 16mm dia. brass, boring it out to 12.1mm dia. then parting it off 2mm long. The boring bar that I have is too big for the job, necessitating mounting it above centre height to clear the bottom of the bar inside the bore, something that I could get away with in an unimportant bore in brass but wouldn't have liked to do inside the drill chuck. The only important part of the job was to make sure that the two faces are parallel, but facing the front of the job then parting it off achieves that.
The spacer being parted off;

Note the Allen key, unlike a lot of larger hobby lathes the saddle of the Unimat can be locked in place (as can the cross slide), handy when parting off.
The spacer in place;

 

Fitting the spacer now means that the drill chuck runs true with no discernable wobble (although ideally I'd like to check it with a DTI).

Paul.