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

[ToddF]

Originally Posted by Oblarg

If one were to couple two 1/2'' aluminum hex shafts on a drive train with a hex sleeve, how small of a coupler would you be comfortable with? I am wondering if 3/8'' on each shaft would be sufficient.

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.