Quote:
Originally Posted by Bruceb
Well, maybe they didnt change it after all. The shaft, after I took it all appart, is press fit into the bearing and then trapped buy a steel ring behind it that is about .375 wide and looks for all the world like just a piece of steel tube but it only fits on the shaft one way like it has a mating taper behind the bearing.
Tristan, did you use hardened steel for the shaft that you made?
Bruce
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That's how it worked on the old drill. The retaining collar was a press fit, and though the inside may have had a taper (I never checked), the shaft itself was straight.
We didn't use hardened steel for the shafts, and that was a mistake. The steel we used (AISI 1018 first, I think, then AISI 12L14) was weak and ductile, and the torque of the drivetrain caused it to twist at the interface with the planetary gearbox after repeated back-and-forth cycling. In retrospect, we should have just used AISI O1 drill rod, and then hardened and tempered it.