Can't tighten Prop Nut without spinner backplate moving
 

Ok, I'm new to electric stuff and I'm trying to mount a prop with a spinner. Onto the propshaft I mount the spinner backplate the prop and then the nut. When I go to tighten the nut the spinner backplate turns away from the prop and the spinner will then not fit the pegs because they have moved. I have not had this problem on glow engines so will someone, anyone please enlighten me?

Thanks,
Andy

RE: Can't tighten Prop Nut without spinner backplate moving
 

I'm surprised you haven't had this problem on glow engines, cause I have. You will have to hold on to the spacer between the backplate and the engine until the prop bites into the backplate enough to keep from moving. I use a small pair of channel lock pliers to hold the spacer while I tighten the nut.

RE: Can't tighten Prop Nut without spinner backplate moving
 

Just cut a disk of sandpaper and glue it to the trust washer. If necessary glue one to the back of the prop also.
Walt

RE: Can't tighten Prop Nut without spinner backplate moving
 

Your post does not say your putting a prop washer between the nut and the prop!

RE: Can't tighten Prop Nut without spinner backplate moving
 

Yes, there is a prop washer between the prop and the nut.

RE: Can't tighten Prop Nut without spinner backplate moving
 

While holding the prop to tighten the nut,the motor is turning when you tighten the prop adapter nut as the shaft is spinning in the prop and the back plate is moving with the motor/prop adapter. If there is no way to hold the motor from turning you need to either grasp the backplate and hold it (and the prop) as you tighten the nut or as mentioned get some friction between the back of the prop and the front of the back plate to help hold the two in place

RE: Can't tighten Prop Nut without spinner backplate moving
 

RCP, where I come from a thrust washer goes between the motor and the prop and a prop washer goes between the prop and the prop nut.

Perhaps my misspelling in the original pot confused you.
Walt

RE: Can't tighten Prop Nut without spinner backplate moving
 

I just had the same problem...... In my case the COLLET was spinning along with the motor and the prop and backplate were being held by my hand. My solution was to pull down on the prop a little to give it a chance to BITE.....then the collet got tighter and the nut finaly got tight.

RE: Can't tighten Prop Nut without spinner backplate moving
 

The OP didn't say it was a collet so it's assumed to be a radial screw-on or grub screw-on adapter.
If it is a collet then the hole in the back plate may not be a large enough diameter to let the prop shaft move through enough to quickly start tightening the collet on the motor shaft and the entire collet is spinning on the motor shaft. Same thing happens with some collets when not using spinners and you have to enlarge the diameter of the hole on the back of the prop to let the collar on the collet shaft move through.

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....

RE: Can't tighten Prop Nut without spinner backplate moving
 

I have the same problem with one plane at the moment where the whole motors spinning and because of the cowl I can't hold the motor.

I was thinking about after I've lightly screwed the nut on after the prop to use a pair of pliers or a grip to hold the end of teh shaft that's now clear of the prop but wonder if that'll just destroy the thread so I won't then be able to get the prop off / put a new one on if needs be. I've also thought about getting a Dremmel and making a cut across the end so I could put a coin or screwdriver across to stop it turning and use a spanner to turn the nut, has anyone tried either of those / do you think they'd work????

RE: Can't tighten Prop Nut without spinner backplate moving
 

Sounds like you might be Botoming the nut on the Threads? Or you could cut a slot in it as your last reply Suggested.As for Holdong the Shaft with pliers I would probably File 2 Flat Sides on the Shaft Just enough to Hold it with an Adj. Wrench? If it is Bottoming on the threads Put another washer under the nut.If it's a Micro Light you might have to rebalance depending on washer thickness.? Just trying to Help?!

RE: Can't tighten Prop Nut without spinner backplate moving
 

Sand paper works perfectly for me !