Velocity

[Mr Ron]

In the course of selecting gear ratios for an 1-1/2" scale electric, what would be a good slow speed for the engine to travel? I'm thinking about 2-3 feet per second. My driver circumference is 27". I don't want too much speed because rod binding could occur and that would not be good on quartering.

[Harold_V]

3 feet/second would be just 2 mph---which is quite slow in the scheme of things.
In regards to rod binding--if that's going to be an issue, it's going to be an issue at any speed. Key here is to ensure it's not an issue by working properly and providing the required clearances of fits.

Harold

[Fender]

Not sure what you mean by good slow speed. Do you mean minimum speed or maximum speed? I can't see any benefit in having a max speed over about 6-8 mph, because most club tracks limit speeds to no more than that. With a good controller and drive train, the minimum speed could be probably less than 1 ft/sec.