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Prop Balancing


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#1 mr_fons

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Posted 28 June 2018 - 08:21 AM

Folks, a quick question (as if a question can be quick) on balancing a prop.

Did the sharpening first and then balancing of the prop all going good except

the prop keeps going to the horizontal position . What am I doing wrong?

 

Many thanks.

Fons

 





#2 John Beardslee

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Posted 28 June 2018 - 08:47 AM

I usually check the balance before starting and mark the heavy blade, then sharpen the light blade first removing the least amount of material as possible. Then start on the heavy blade constantly checking the balance, where are now with your prop is that everything that hangs below center is heavy, so the trailing edge of one blade and the leading edge of the other has extra material that needs to be removed to get the prop to balance ie: when the prop is on the balancer and you rotate it, the prop stays where you put it or stops randomly.
Thanks John



#3 mr_fons

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Posted 28 June 2018 - 09:51 AM

So John as I read this when the prop rest in the horizontal

position remove material in on the side that falls forward. 

 

Fons



#4 Hydro Junkie

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Posted 28 June 2018 - 11:09 AM

Is it possible that the prop hub is bored off center? 



#5 John Beardslee

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Posted 28 June 2018 - 11:55 AM

So John as I read this when the prop rest in the horizontal
position remove material in on the side that falls forward. 
 
Fons


If the prop is horizontal on the balancer and you site down the shaft half of the prop is above the shaft and half is below. Some people refer to this as hub heavy which it could be for many reasons, one of which is if the hole is off center. The majority of props have holes that are slightly off. Either way to run best and not have excessive shaft bushing wear prop need to be balanced. Some people remove material from the side of the hub that is below the shaft and some remove material as I said earlier from the blades. I should also say that I only remove material from the back of the blade not the face. Feel free to call me if youd like, its sometimes hard to explain this stuff in writing. 586-747-2372 Or call Mark Sholund and order one ready to go.
Thanks John

#6 mr_fons

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Posted 28 June 2018 - 01:12 PM

Thanks for the help and yes John I have ordered from Mark before.

 

Fons



#7 John Beardslee

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Posted 28 June 2018 - 01:44 PM

Thanks for the help and yes John I have ordered from Mark before.
 
Fons


Im a class B bachelor for a couple of days so give me a call if I can help

#8 shoboat

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Posted 29 June 2018 - 05:11 AM

Fons,

 

Most Crankshafts, drive shafts,drive dogs, and prop nuts are not balanced.

Try to get them the best that you can.

 

Have Fun Testing,

 

Mark Sholund



#9 Hydro Junkie

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Posted 29 June 2018 - 09:15 AM

Mark, in the case of a drive dog, would it be worth putting it on a lathe and shaving it down to be sure it's bored in the center or could the set screw be part of the balance problem?


Edited by Hydro Junkie, 29 June 2018 - 09:17 AM.


#10 shoboat

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Posted 29 June 2018 - 10:56 AM

Mark,

The whole shaft is a problem with balance.
The drive dog set screw locations and where
you grind or drill for the set screw placement
on the shaft. Like I told Fons just do the best
that you can. 20,000 to 37,000 rpm is quite a
bit at the end of a shaft when you think about
It really.

Enjoy Testing,

Mark Sholund