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

[AustinH]

We used 1/2in hex bar with 1/4-20 all thread in the ends to make our toro sticks. We threaded that piece into the end of a 1/2in hex output shaft on a Versaplanetary gearbox. We used a 2" vex spacer to lock the rotation of the toro sticks. Best guess, we had ~3/8 inch of engagement on the sticks. We modified the spacers to accept a hose clamp on the gearbox end so that they wouldn't go anywhere. If I remember correctly, on the second day of qualifications at PNW champs, we lost one of our toro sticks when one of the delrin spacers cracked, but otherwise they worked great, and they were cheap and easy to replace. YMMV