ORIGINAL: JohnBuckner
If you are using a spinner nut such as this:
http://www3.towerhobbies.com/cgi-bin...&I=LXE158&P=RF
There is absolutely no need for a washer. I use a lot of these and and infact the machined in nut face is superior to a typical washer, they are intended to be used without a washer.
John
I use these prop nuts like John is showing plus a couple of different types. On some planes these look good and work great. As John stated, no washer needed, they are designed to be used without the washer.