Tuesday 15 November 2016

Replumbing my toy traction engine

The steam valve on Wilesco toy traction engines (and steam rollers) is rather basic. It has a plastic lever, which is loose when cold, and goes from closed to fully open in less than a quarter turn, making it rather difficult to set the engine speed precisely.

I decided to replace it with a better quality "globe" valve to give finer control, and to move the valve to the driver's end of the engine. I also wanted to add a displacement lubricator to ensure the cylinder is always well oiled.

As Wilesco is a German company their models use metric threads throughout, whereas British steam models still use imperial sizes. I prefer to work in metric so bought all the metric fittings I needed from a German supplier Modellbau-Niggel. I was at least able to buy metric pipe from a British supplier, Macc Models.

Connecting the steam valve to the boiler


Rather than run a pipe from the original steam valve position to the driver's end of the engine I decided to move the whistle to the original valve position and connect the new valve to where the whistle had been. This would require quite a complicated bit of pipe bending with three 90° bends in close proximity.

I made a simple pipe bending jig out of washers, nuts and a bolt. Cutting away the side of one of the washers allows bends to be made in close proximity, as well as making it easier to remove the bent pipe from the jig.

Replacing the Wilesco steam valve

After bending the pipe and cutting it to length I soldered pipe nipples (or cones) to each end. As you can see, I used a bit too much solder on one of them.

Replacing the Wilesco steam valve

The completed globe valve connection.

Replacing the Wilesco steam valve

If you've browsed the Modellbau-Niggel web site you may have noticed that they don't sell a globe valve (or oiler) with 3mm pipe connections. I used their part number 310 425 which has an M6x0.75 threaded inlet and a 4mm pipe nipple outlet. I shortened the threaded inlet and then used a centre drill to make a seat for a 3mm pipe cone. I used a sleeve of 4mm brass tube to solder the outlet nipple to 3mm pipe.

Connecting the lubricator to the steam chest


The traction engine's "steam chest" uses a flared pipe connection with an M6x0.75 nut (or screw, as it has male threads) to clamp the flared pipe to a sealing washer. The pipe is about 3.7mm diameter, so I couldn't simply reuse the nut with my 3mm pipe.

Replacing the Wilesco steam valve

Instead I used part number 706 675 which is a good fit on 3mm pipe. I cut off one side and shortened the other, then filed off the thread at the very end so it fits the steam chest. Then I flared the end of some 3mm pipe.

Replacing the Wilesco steam valve

After bending the pipe and soldering a 3mm nipple to the other end the oiler was fitted to the traction engine.

Replacing the Wilesco steam valve

As with the steam valve, the oiler I used (part number 400 104) has M6x0.75 threaded connections on which I used a centre drill to make seats for 3mm pipe nipples.

The final connection


The last bit of pipework is much simpler, apart from sleeving one end to fit the 4mm outlet of the steam valve.

Replacing the Wilesco steam valve

Initial tests show everything is working as it should, and the new steam valve is a considerable improvement. I've yet to determine the optimum setting for the oiler's needle valve, so am erring on the generous side for now, giving it one whole turn from fully closed.

Saturday 12 November 2016

Making a canopy for my Wilesco traction engine, part 3.

In two previous posts I discussed designing a canopy for my toy traction engine and committing the design to metal. In this post I show the final stages - painting and adding decals.

Replacement canopy for Wilesco traction engine

After filing away excess solder and sanding down all the brass parts I started painting by giving the entire canopy a couple of coats of etching primer from a spray can. To support the canopy during painting I re-used my support strut jig, opening up two of the holes to take M4 screws.

I forgot to take any photos during the rest of the painting. I used Humbrol enamels, thinned with white spirit. I found it quite difficult to get a satisfactory matt finish on the upper surface of the roof ("dark slate grey", no 224) but after enough coats and a gentle buff with a rag I think the result's not too bad.

Replacement canopy for Wilesco traction engine

I drew some lettering for the sides of the roof using the LibreOffice "oodraw" program, and then printed the result on an A4 sheet of water slide decal paper. (I also did some lettering for a simple trailer kit I've built.)

Replacement canopy for Wilesco traction engine

After attaching the decals there were a few bits of white showing around the edges. I touched these up with more paint after the decals had dried.

Replacement canopy for Wilesco traction engine

Replacement canopy for Wilesco traction engine

These two pictures show the canopy in place on the traction engine. I think it looks pretty good overall. The video below shows how easy it is to remove and replace, thanks to the magnets at the bottom of the support struts.

Replacement canopy for Wilesco traction engine

Wednesday 9 November 2016

Improving my Wilesco traction engine's wheels

The biggest fan of Wilesco toy steam engines would have to admit that their traction engine's wheels are not particularly attractive or realistic. (Yes I know it's a toy, not a scale model.)

Wilesco toy traction engine kit

A popular way to improve the appearance of the rear wheels is to replace the pressed steel spokes with complete Mamod traction engine wheels. Mamod wheels are castings that look a lot better but can't be used directly as they're too small. Fitting them inside the Wilesco rims gets round this problem.

Improving the Wilesco traction engine wheels

I bought a pair of old Mamod wheels on eBay. Their paint was in poor condition so I stripped them back to bare metal. The Mamod wheel's centre hole is ¼" diameter (6.35mm) compared to 5mm on the Wilesco. I cut two lengths of 6mm OD (5.1mm ID) brass tube and wound them in three layers of thin aluminium tape to make snugly fitting adaptor bushes.

Improving the Wilesco traction engine wheels Improving the Wilesco traction engine wheels

I bought a custom length axle with brass hubcaps from CJW Steam Ltd and made shorter replacements for the Wilesco brass spacers using some more of the 6mm brass tube. I then assembled everything to make sure it all fitted and that the clutch would still engage and disengage correctly.

Improving the Wilesco traction engine wheels Improving the Wilesco traction engine wheels

The next job was to prime and paint the Mamod wheels. I used an etching primer spray followed by two brush coats of Humbrol red gloss enamel.

Improving the Wilesco traction engine wheels

While the paint was drying I removed the Wilesco rims from their pressed steel spokes. I found a suitable size tin of paint to support the inner part of the wheel (with a bit of old T-shirt for padding) while I gently eased the rim off with a hammer and bit of wood.

Improving the Wilesco traction engine wheels

The Mamod wheels are several millimetres smaller than the Wilesco rim's inner diameter so I put a spiral drive belt (as used to drive toy steam engine accessories) around each wheel to make them a better fit. I then glued the wheels inside the rims with epoxy resin adhesive.

Improving the Wilesco traction engine wheels Improving the Wilesco traction engine wheels

Finally I filled the gap between Mamod wheel and Wilesco rim with some Milliput and, once it had set, painted it and touched up some other damage to my earlier paintwork.

Improving the Wilesco traction engine wheels

I'm very pleased with the final result. You'll notice I've also doubled the number of spokes on the front wheels. This is done by removing one of the pressed steel centres from the rim and then replacing it with a 30° offset. I also gave the front wheels a coat of the same red paint as their original colour is a slightly more orange shade of red.