I'd always made wagons and vans from card, and locos with brass chassis and styrene bodies. Then I met John Fownes from Nottingham who persuaded me to make a loco from card, he makes huge 7mm express locos and rakes of coaches from it!
1/. The chassis drawn out and cut from card leaving some overhang at each end so the two pieces can be stuck together. The front axle hole drilled out and reamed with the file to take the 1/8" bushes.
2/. 'T' shaped spacers glued to one side only. Lined up by eye on the cutting board. Bit of rod through the bushes, tested, taken apart, white glue on one spacer, reassemble, enough drying time to get it square again, same with the other spacer.
3/. Gluing the High Level horn blocks into the slots which are 1/2 mm wider to allow for some wiggle. An old Biro spring to hold them in place, when lined up some Araldite on the edges with a pin.
4/. The wheels as in 1/. and 2/. with every other spoke cut out. New axles make from 1/8" silver steel. I file flats at both ends at about 1/2 the depth of the wheel bushes. This is where Seccotine comes into its own it will hold the axles in place fairly strongly but still leave some small adjustment capability. The pivot for the rear axle will go between the white card.
1/. Ready to glue the motor between the frames. I glued the pivot in using a pair of tweezers from the corner shop bent to make a clamp.
2/. The connecting rods ready to be drilled and a bit of copperclad PCB sheet cut to take the pickups. Sadly the worm and gear you see here didn't work very well, my fault I suppose, I had to break out the motor. Fit a small Scalelink 40:1 W&G, pack up the motor cradle with some thin card, I glued the motor back in with Seccotine, just the right stuff to use for a job like this.
When I get round to it I'll make the body and outside cylinders.