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Old 31-01-2012, 11:26   #1
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How to Balance a Folding Prop

I have an old gori 16x 13.5 folding prop. I have been experiencing a lot of trive train vibration and this year I plan on resolving it.
I took the prop off the shaft and withed the two blades. I was suprised to find one 52 grams heavier that the other. There is evidence of corrosion and cavitation.

I would like to know the best way of removing the 52 grams of bronze with out unbalancing the blade.
Currently i think I should find the point where the blade balances on a .5 inch dowel. Then drill a series of holes around that point untill the blades weigh the same. I can then fill in the holes with epoxy.

Does anyone have other proven methods to remove the excess and still keep the blade reasonable balanced?

thanks,

Mike
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Old 31-01-2012, 11:58   #2
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Re: How to balance a folding prop?

Good lord take it to a prop shop and get it done right !! to expensive to try home repairs like this !! a shop can repair and balance it right the first time and you will still have prop to work with !! Just my 2 cents Bob and Connie
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Old 31-01-2012, 12:47   #3
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Re: How to balance a folding prop?

+1
Take it to a prop shop for balancing
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Old 31-01-2012, 13:17   #4
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Re: How to balance a folding prop?

It has to be spun balanced using a computer, preferably on you prop shaft.

Are you sure your not getting shaft whip. All it takes is the motor (coupler) to be out of alignment.
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Old 31-01-2012, 14:27   #5
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Re: How to balance a folding prop?

I'd agree that the entire assembly has to be balanced, not just the blades. But once assembled and jigged up so they can be balanced...shouldn't it just be a matter of patiently grinding/polishing down the heavier blade, until it is in balance?

Yes, a shop should be able to make quicker work of it, but once upon a time this was not considered rocket science, just patience and "sanding".

52 grams off--but how much does each blade weigh? What's the context on the 52 grams?

With nearly two ounces of metal to polish off...that's a lot of imbalance.
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Old 02-02-2012, 12:02   #6
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Re: How to Balance a Folding Prop

the blades weigh 1986g and 2038 g so 52 grams seems significant.

I have also identified missalignment at the engine coupling/shaft and will replace both.

Thanks for the input. It looks like I'll drop by my local prop shop.

Mike
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