We are wondering if anyone has had issues with 1/2 6061 hex being slightly oversized. We are having difficulty in getting bearings to slide on. We have no problem getting them to slide onto steel hex. Wondering if the 7075 from online metals is any closer.
I’m not sure which stock you are using, I assume McMaster or Vex. I’ve had issues with hex stock from McMaster being out of tolerance, especially aluminum, but usually a fine file to hit the high spots works well. That’s why I’ve mainly stuck to Vex stock the past few years, since it’s well toleranced.
We had purchased some from a local suppler, and had the tolerance issues. Really need the higher strength of the 7075 (we think) but didn’t know what to expect. The steel works but switching out to 7075 will save 4+ pounds.
Vex hex stock is 7075, not 6061.
To the OP: Please look into using 7075 aluminum for your hex shafts. In some low load applications 6061 can be fine, but it is not as strong and can fail in locations such as a drivetrain.
Would highly recommend the Vex hex shaft, which is really well toleranced for FRC slip fits. If you get 7075 from someone else, check the tolerances for this sort of thing, you want tighter tolerances than just hex bar extrusion.
We have had bad luck using 6061 hex shaft from McMaster, between breaking many shafts and having issues with fit. Since then, we always purchase the 7075 from AndyMark. It is slightly undersized I believe (~.496-.499") and a lot stronger than 6061. We have never tried Vex’s before.
The VEX “thunderhex” stock is nice because it also has a 13mm OD turned to knock off the corners, so you can use 1/2" hex or 13mm round bearings on it.