I've made some further progress with my PenBits sprung bogies for the Class 40. The modified Bachmann drive gears have been fitted to the new Gibson axles and the pony truck frames have had the axle bushes opened out to 2.4 mm ( from 2 mm) to accept the extended axles that I recovered from my part-completed Lima Class 40.

Here are the three driving and pony truck axle (for the second bogie) The gears have been drilled out by a friend to be a good push fit on the axles, but I applied a smear of Loctite Bush Retainer, as a precaution. The pony truck axle has been reduced to 2 mm diameter in the centre to make sure it clears the truck retaining wire:

Next, the first bogie with the wheel sets and springs fitted. I'm pleased to report that it pushes along very freely, so all that hacking about of the gear train, which caused some trepidation, appears to have been successful. Mind you, testing under power will be the key. Regarding power, the kit instructions describe a pick up system using shorted out wheels on opposite sides of the two bogies, but I don't really fancy trying to solder wire to the wheel rims (seems like a recipe for melted wheel centres to me) so I'm going to fit conventional wiper pick ups. Two pick up mounting bus-bars have been attached to copper clad pads to facilitate the pick up wires (still to be made and fitted). These bus-bars have to be in two parts because of the articulated inner chassis, hence the blue insulated wire loops connecting the two sections. There will also be a further jumper wire on each side to take the power up to the bogie mounting piece. From there, the original Bachmann arrangement connects to the loco circuit board via sprung contacts:

The second bogie has now been assembled to the same stage, so they have been fitted to the loco for trial pushing through some point work, prior to fitting the pick-ups. Here are three shots of it at the yard throat on the layout. After an initial derailment, possible due to not having all the wheels properly on the rails, it has pushed successfully through the double slip and even round the extremely tight connection to the mill siding. It wouldn't be expected to go round there during operation.

No excuses not to move on to the pick-ups now and then test under power.

Dave.

Dave.