As amazing as it may seem, my 3D printer can actually print Porto:87 wheels that sort of work. Not only that, but a Mod 0.5 20-tooth gear downloaded from Thingiverse printed successfully and runs as well!
I wouldn’t expect the wheels to hold the track at speed through a turnout. And the spur gear is unlikely to last. However for proof of concept testing on the test track, they work fine.
Naturally, the wheels don’t pick up electricity at all. So, a couple of test leads had to bridge the gap. Peeling the insulation from Percy’s pickup wires has been the only permanent modification so far.
Pembroke:87 