Had some 2mm roller bearings delivered this morning so was able to make up a pony truck to my own design this evening. I have completely ignored the one which comes with the kit as I have found this approach to be the only way to keep it on the tracks with the other Baldwin. Firstly some brass strip was soldered together the marked out drilled and filed to shape. When separated (quick touch with blow torch), you have two identical pieces;

Just s little reaming to get the bearings to fit and a touch of Loctite to hold them in. The frames are held apart by an ordinary loco frame spacer with a notch filed out of it so the head of an 8BA bolt will sit flush. The sides are then screwed on but left loose with the bolts being secured with Loctite introduced via the filed notch. This allows a little compensation and the whole unit to rock back and forth. It is then pivoted directly through the cylinder block;

So here we have the chassis so far;

Although you can't see them behind the wheels there are roller bearings on the two front axles and the whole thing is running very smoothly indeed. If you fancy trying out roller bearings I have found SMB Bearings to be excellent and have used SFR 144 ZZ SMB for the 1/8th and SF 682 ZZ SMB for the 2mm.

Another thing that is a bit unusual on the chassis is that I have used Gibson style wheels on the two outside axles but had some flangeless wheels to use, as per prototype, on the center wheels but these are Romfords so have two sorts ox axles on the one loco!