Having solved the issue of the wheels touching the upper frame I then discovered that the wheels were touching the inside of the frames when going around a 6ft curve.

So I added some styrene insulation either side of the inner frames.

This cured the short problem but running trials revealed that although it would now go around 6ft curve without shorting it didn’t do so reliably without the trailing truck derailing.

In an attempt to cure this I tried introducing some weight on to the trailing truck. I cut a couple of rectangles of lead and using a V block and a couple of different sized rods I created some weights that fit on top of the ruck over the axle.

I was getting low on lead but just this week we have had a couple of chimneys repointed and re-leaded as well as four wet verges I asked the roofer for the lead that they removed so I now have sufficient to see my days out I think.