Balancing folding props

[ahdofu]

I am suspect someone may have already asked this question but the search utility did not find any. Anyway is there a reliable way of balancing a folding propeller assembly? I tried to use my old prop balancer tool but it is somewhat cumbersome to make sure that the two rotors are on the same plane.

 

[Konrad]

Let me first start out asking why? Are you trying to bring damaged blades back in to serviceable condition? Yes, it can be done but it is a process. You will need some sensitive tools to get any meaning full results. You will need to be able to measure the mass of each blade and the moment arm this mass in centered upon.

Now most folding props have a very low safe RPM limit that it makes it actually very difficult to to get better results than what one sees in blades and hub assemblies from reputable firms like Aeronaut.

You might want to Google "dynamic balancing" rather than "static balancing".

 

[ahdofu]

On the package of the folding prop it states that the props need to be balanced hence the reason. I had googled and found a video on balancing. That process required some skill and the ability to hear tones which I don't think I can do. Anyway if you don't balance your props and don't think is needed then I'll forgo it as well.

 

[Konrad]

What props are you using?

 

[Nigel]

Like Konrad said, most folding props will never safely reach an RPM where balancing becomes a critical issue. You could do some trial and error to see if you can eliminate some vibrations, but unless it's at the point of breaking your motor mount, I don't see much of a point.

 

[ahdofu]

It is an Aeronaut fold 12.5x6. On its notice it states: "Before assembling the blades, debur the various edges and the root. Balance the propeller when assembled ...". If you guys don't balance your props then I won't either.

 

[Nigel]

Personally... I don't. I've never had an Aeronaut so out of balance it causes any harm. Minuscule efficiency loss, sure, but never a broken motor mount or excessive vibration.

 

[Konrad]

With Aeronaut folders just make sure the blade pivots freely. (You haven't over torqued the pivot pin nut). With some blade sizes you might want to extend the parallel side of the blade root to make sure the blade is free to move in the yoke for the full range of motion needed.

If you can measure in micro grams after deburring then.....

 

[Wayne]

Aeronaut does a really nice job with their props these days. About 20 years ago they were not as nice and to did want to clean them up and may require a simple balance. I think they have invested in better tooling and such and really do offer nice clean blades now.

 

[Konrad]

I've always found the black ( carbon reinforced) blades to be better than the white plastic blades. Don't know if it was a tooling issue, process issue or material issue. But for sport flying I like carbon blades from both Graupner and Aeronaut .

Now these should not be confused with the hand laid continuous fiber blades for real high powered application.