Harold Jones

I HAVE INTENDED TO TRY out a split frame loco for some time, as I feel that with all wheel pick-up, the running must be better than either conventional or American style pickups. So, I quizzed Sandy Harper who was demonstrating split axles at the 2015 Telford show and went away determined to try it out. I had in stock a Frank Smith 47XX kit with a Precision chassis purchased at the Leigh show. This would be ideal, with 8 driving and 6 tender wheels it should never stall.

Before I did anything rash, like spending money, I made up several split axles, following the instructions given by John Rodway in his article on the manufacture of split axles in the Gazette, Volume 16, No. 7, page 22. Very concise and informative.

But, if I may add a couple of hints; Threading the fret saw blade through the hole in the axle to cut the slot was a pantomime. Despite what we say, railway modellers do not have a third hand!

The solution was to hold the fret saw frame in the vice, enabling me to fit the blade and tension it without further difficulty.

To keep the Araldite used to provide the insulation just where it is needed and to keep cleaning up to a minimum, I used heat shrink sleeving to protect the rest of the axle. No need to heat shrink it, just use a piece that slides on easily. This makes cleaning up very easy.

Use of heat shrink sleeving to keep axle free from araldite

Thus, buoyed up by false confidence I proceeded to make my mistakes!

After some thought I opted for a set of machined cast iron wheels from Walsall Model Industries. As you have insulated axles, the wheels should not be insulated. At the moment Tufnol rod was not readily available from model suppliers, so I bought a 4 foot length from a commercial supplier. Talk about a life-times supply! I turned up four of 7/8 in frame spacers and tapped them 8BA to replace those supplied with the frame kit. The spacers protrude above the frames to provide insulation when the metal foot plate is fitted, other wise you will have a dead short.

Mistake No. 1 – I considered that the driving axle could not be insulated, so ordered 1 pair of insulated drivers and made a pair of insulated bearings from Tufnol for this axle. This worked very well until I fitted the coupling rods, as the wheels are spoke insulated this introduced a complete short circuit!!

Very obvious with hindsight.

So I drilled out the crankpin holes and fitted Tufnol inserts to take the crankpins on the driven wheels. We shall see how this wears in use. I do have enough material to make a few more if needs be! To prevent these bearings from rotating and possibly wearing quicker, I used some Araldite from the split axle manufacture, to secure them to the frames.

And with my 3rd hand I thread the blade through the hole

Mistake No. 2 – I don't like waste, so decided to use the rest of the Araldite to secure the remaining brass, current carrying bushes, into the frames!! Luckily I did realise what a twit I was becoming and cleaned all the araldite off before it set solid and insulated the bearings from the frames (split frame pickup!)

Mistake No. 3 – I carefully marked the axle for the split, using a black felt tip marker and very carefully drilled the 2 holes required and cut the very short slot. Fitted the heat shrink sleeving to make cleaning up easy, applied the Araldite and left overnight to cure.

Perfect.

I then used the lathe chuck to hold the axle, donned my Optivisor for better vision and proceeded to make the cut as per John Rodway and Sandy Harper's instructions.

Perfect.

I then made the second cut. After congratulating myself on what was a tricky bit of work, I noticed that I had made both cuts from the same side. Still, it will be easy to make good with more Araldite and there is the other end of the axle to try again with!

When using a fret saw you are going to break blades. Don't throw the broken pieces away, they are just the tool to spread the Araldite thoroughly in the slots you have cut in the axles.

When the loco was completed I was very impressed with its performance, not least the very smooth control and the ability to negotiate my curves.

However, as I feared, the leading split axle was not strong enough to stand the stress of grinding round 3ft radius curves and after a while it broke. So it was plan 'B'. I ordered a further set of insulated wheels to provide one side fully insulated

Again, I have tried and liked the result, but feel that a slightly different approach may better suit my needs. True to my butterfly mind, I have decided to bring forward the build of my latest buy, a CCW GWR 22XX 0-6-0, to try out a modified split frame build.

All axles on the tender are split, whilst the loco will have a non-split driven axle and (don't forget, I do not like waste), the 2 remaining good split axles from the 47XX.

The centre driver has some sprung up and down movement to aid pickup and adhesion.

This is coming on very well, who knows, I may even finish both sides!