Let's talk about Spinners & Balancing!

Aluminum Spinners are beautiful,  functional, and will enhance the general appearance of most any airplane. But not all aluminum spinners are created equal. And even the top-of-the-line spinners can be a problem sometimes.  Every aluminum spinner WITHOUT EXCEPTION must be checked for balance especially if you altered it to fit your favorite prop.

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This spinner developed a crack during flight. It's about an inch long and was destined to explode probably on the next flight. Although this is rare, as you can see it does happen. This is a spinner that was supplied with an ARF, and was grossly out of balance. The crack suggests it was still somewhat out of balance, or possibly had metal fatgue from the engine and/or prop vibration.   

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Use a Dremel Mototool and a 1/2" sanding drum to remove metal from the INSIDE of the spinner, starting at the nose moving back. Do not remove metal from the backplate except in extreme cases of bad balance.

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If your spinner won't fit your prop balancer just make a base out of something that will support the assembly. It doesn't have to be anything fancy (like the one in the photo), a piece of 1x4 board will work just as good. Your axle may be too short for big spinners. You can not use "music wire" like the stuff sold at the hobby stores! It will not work. period. It's not accurate enough in straightness or circumference. You will need a piece of drill rod. It's cheap, and readily available from a number of places.

I prefer the "old fashioned" rotary disk balancers as opposed to the magnetic support type. The magnets (while more accurate) have a limited holding capacity, and usually won't hold a very big spinner, or prop for  that matter.

I won't mention brand names, but I will tell you that "you get exactly what you pay for". So, the next time you go shopping for an aluminum spinner, don't make price your only deciding factor.

OK, now let's talk about PLASTIC Spinners. They are WORTHLESS, should be outlawed... You can't balance them and are not factory balanced. They also burn grooves when your stater cup slips on them. The IMPORT aluminum spinners are not much better, but at least you can balance them.  

Copyright 2004 M. B. Fuess