RE: Can't tighten Prop Nut without spinner backplate moving
I have that problem all the time when using a plastic spinner.
And, if you have a completely cowled motor, you can't get a hold of the motor to hold it!
I have, as a worst case, resorted to putting a drop of thin CA between the prop and the spinner back plate.
That seems to always work for me....
It's not a great way to change props in the field however.
When changing props, you will have to break the CA bond, but it's not too hard if you don't use too much CA.
I hate to admit it, but I have also wedged a screwdriver into the front of the rotor (when I can reach in there
between the spinner and cowl). I am careful not to touch the copper wire windings.
Then I can hold the motor from turning when tightening the prop nut.
I sure don't like the idea of grabbing the motor with channel locks, and sandpaper between the prop and backplate
doesn't sound too good either.
Good luck.... it's a constant battle for me....