Hi, I had a 10 x 5 prop on my OS 40fx engine.. It was in my Eagle 2 trainer. I was told that a 11x5 would be quieter and pull it along just fine. The problem is I can't find a spinner that fits the 11x5. I was told I could trim away some of the plastic spinner to make it fit. Still didnt fit so I purchase a bigger spinner and removed some of the plastic... This made the spinner spin out of balance.... what would be the correct spinner for this size prop.... ps I am using the gray plastic prop....

Spinner sizes aren't dictated by the propeller size. They are usually (although not always) by the fuselage of the plane they are on. To be honest here, it's rare that you will get a spinner prop combination that doesn't require some bit of trimming of the spinner to get the prop to fit properly. When trimming a spinner care needs to be taken to trim the same amount of material from both sides of the spinner in order to keep it in balance. An easy way to do this is to mark the spinner with the area you want to remove. The way you can make sure that you remove the same amount of material from both sides as you trim it.

Ken

I'm not very good at trimming nylon spinners.

I got rid of the nylon spinner on my trainer and replaced it with a "spinner nut." The spinner nut is aluminum (brass versions of some are also available) and replaces the steel nut that currently holds your prop on.

Here are links to different styles that will fit your 40FX.
http://www2.towerhobbies.com/cgi-bin...?&I=LXE158&P=0
http://www2.towerhobbies.com/cgi-bin...?&I=LXHBR7&P=0
http://www2.towerhobbies.com/cgi-bin...?&I=LXK241&P=0
http://www2.towerhobbies.com/cgi-bin...?&I=LXL745&P=0
http://www2.towerhobbies.com/cgi-bin...?&I=LXCC39&P=0
http://www2.towerhobbies.com/cgi-bin...?&I=LXCC40&P=0
http://www2.towerhobbies.com/cgi-bin...?&I=LXKE20&P=0

For many planes I think a spinner nut looks just as good as a spinner. For planes that need a real spinner, I either get my brother to do the trimming or get a Tru-Turn aluminum spinner. So far, my Tru-Turns have fit my props with no need of modification. I like them, but they are expensive. If you order direct from Tru-Turn you can have them cut the slots for the specific prop you're running.

Carrell, those are the only spinners I use on my glow planes
form meets function, ano'd ones to trim out your color scheme to boot.