Thanks, I have to try that. I have never drilled in a threaded hole before.
I think our real problem on the spin-tech replacement is that they didn't thread the screw hole all the way thru so it is impossible to tighten the screw against the shaft of the motor! That is why we cannot get it tight enough on 2 replacement units we have! They did a poor job threading the units. I found the same problem with another type of spinner plate as well!
(Note: I also found that different 12 volt motors with 1/4" shaft have a slightly different shaft diameter. SO the Spin-Tech as designed may work on one motor but not another even though both at 1/4" shaft).