Amount of coupler purchase required on 1/2'' hex?

[Oblarg]

Originally Posted by ToddF

I can answer this in three ways
1) WAG: I'd be comfortable with engagement of at least 1D. So, for 1/2" hex, I'd have 1/2" engagement on each side.
2) Experience with what works: In our WCD style drive trains, we use VEXPro #25 hex sprockets. These are .361" thick, and we have not seen any signs of load related wear on either the sprockets or the axles. But, we haven't really disassembled and looked for wear, either.
3) Analysis: Haven't done it. Probably won't. It would take a good bit of thinking to decide how to come up with an answer based on analysis.

Thanks.

The reason I ask is I'm playing around with some drive train designs and am wondering how feasible it would be to couple an output shaft from a gearbox and the center-wheel shaft of a 6WD inside a piece of 2''x1'' tubing. 1'' isn't all that much space to work with to start, and once you account for the bearing you're left with ~3/8'' of engagement on each shaft. I could use 2''x1.5'', if all else fails, but that's significantly heavier and takes up more space.