Originally Posted by Thomas Nelson
I'm thinking maybe I don't understand your question, Michael.
I haven't found the need to grind flats - especially with 4 grub screws. I am sure of this since when I disassembled the failed unit there was no evidence whatsoever of the grub screws having slipped rotationally.
Now you are possibly thinking that for the runout to change mid flight something has to move. But the slip is not rotational in nature ... I'd have seen evidence of it on the shaft. The slip must be along the axis of the shaft, and it must be ever ever so miniscule. I truly don't see how flats could prevent this kind of movement.
One last thing. Depending on the tightening sequence and torque used with the grub screws, you can alter the runout of these adaptors. Zero runout is obviously the target, and so we make a reasonable number of trial & error attempts so as to end up with (1) equally TIGHT grub screws and (2) next-to-zero runout. Having or not having flats would neither help nor hinder this process.
Or am I completely missing the gist of your question??
completely agree with your assement TN
I think if I had this problem I might try using hysol and try to get 3 or 4 drops at the bottom of the hole so that the waxed up motor shaft is in the glue, like a 1/4in of the end of the motor shaft. then install/tune the adapter to the motor and set aside in the proper orientation so as the glue levels out evenly and let cure......I think that might work.
just a thought