I am trying to use a prop nut on my crankshaft to secure the prop instead of a spinner seeing that the nut has some more weight to it to help balance my plane. The crankshaft seems to be a little too long for my nut so I was wondering if I could use a couple of flat washer (which are the right size for the crankshaft) between the prop and the prop nut to secure it in place.

Yes, as long as they don't fit too sloppy on the shaft.

You also might want to put a little Loc-Tite between the washers (if you have more than one). Two or more washers together have a habit of slipping and allowing the nut to come loose.

I would consider getting a second prop washer versus a regular washer. The reason is that they seem to fit well on the crankshaft and many regular washers are loose. Brand is not important. Just find one that is for the correct shaft size. Finding it locally would be best since shipping one washer would be expensive.
http://www3.towerhobbies.com/cgi-bin...CH=prop+washer

Well I put on two 5/16th flat washers that seem to fit pretty good on the crank shaft along with the prop nut and it seems to be very snug. I know that it can all come loose very quickly thought once things start spinning so for piece of mind I might go buy a couple of 5/16th prop washers instead. If anyone has used just regular flat washers, let me know how it worked out or did you have to swith to prop washers?

Thanks for the input

I took an old broken spinner backplate. Cut it down to the size of the thrust washer and used it. The hub on the APC "W" series props are very thin. That's how I came across this.

david

I like David's idea. Put the cut down backplate behind the prop, then one washer and the prop nut in front. Everything should stay nice and tight.

If you don't have a backplate to cut up, and the flat washers you found fit well, I would use them.

Harry Higley also offers prop spinner nuts in different lengths to accomodate your needs. You can get them in different weights to make your balancing needs easier too.

Bill, AMA 4720
WACO Brotherhood #1

Also, put some plumber's tape arount the threads before screwing the nut on - less chance of it working loose.

Cam

Not sure of the plane you are using it on but I have used a heavy hub inside of a spinner before. It gives you the weight you need and you can still keep the look of the spinner. But, that does depend on the size and shape of the spinner you use.