I’m halfway through the same build, all the gears run very well so far but tend to stiffen up as the gear train gets longer.
Hi Bervie1
When I built the express train I had the same issue of more cogs the stiffer it got. Trouble was I didn't really test it until I have finished so I had total drive train to try and work out the friction points. I had used "hot wax" to smear mating/bearing surfaces and it had quite a bit of minute hard wax lumps to get rid of.
On the Roadster I did three things based on learning from first kit.
1. Make sure there are no burrs on the cogs/rollers or bearing from where the it has been released from parts sheet. This is a classic example of where meticulous attention to detail is needed.
2. I used Vaseline lightly smeared on the bearings/cogs and on any cog faces that are "against" another surface.
However I made a mistake on the engine bores using Vaseline because the piston down stroke was "gravity" driven and because the pistons and con rods are so light, the Vaseline was too sticky so "gravity" was insufficient to get them to drop. Had to take the engine to bits clean off Vaseline from pistons and bores and rebuild.
3. Also, like you, I made sure I had free movement at each stage of sub assembly and when uniting sub assemblies together then I exercised the new complete higher assembly so you can identify friction points as they occur.
Its a great model.
