Prop Balancer

[Bruce Tuncks]

In the latest Pacific Flyer there is an Aircraft Spruce ad for a dynamic prop balancer.

 

Well it looked good to me, but I don't even know the theory of how it works.

 

Should we all be getting our props balanced with one of these?

 

Anybody know?

 

cheers,

 

Bruce

 

 

[Vev]

Hi Bruce,

 

 

I would think balancing a prop would be a good thing. Whilst I don’t have any first hand experience with balancing, I have grown to appreciate the positive impact of getting the blades pitch the same in terms of achieving smoothness. I fitted a carbon fibre ground adjustable prop almost 200 hrs ago to my 160…. The adjustability aspect is great for performance set ups but it’s fabulous for reducing vibration with identical blade settings. I can’t imagine that prop balancing wouldn’t be a positive step forward..... I’m also keen to know if these gismos work too?

 

 

Cheers

 

Jack

 

 

[Guest Decca]

Hi guys. Static balancing and other prop maintenance issues can be achieved without going to the expense of dynamic balancing, especially if you're an L1 or L2, google this sight [ thompsonaeronautical.com ]. You're on the right site if you find a magnificent wooden prop on a Tiger Moth.

 

From the main menu select "How to Articles" and read the very helpful texts on:

 

Maintaining & storing wooden props

 

Refinishing ......

 

Static balancing.........

 

Trailing & leading edge repairs....

 

& Making props more visible.

 

There are also video presentations of the text versions.

 

With practice & care you can maintain & static balance your wooden prop to a high standard.

 

Regards, Decca.

 

 

[theoy]

HI Jack

 

What brand of propeller did you put on your J160?

 

Cheers Theo

 

 

[Vev]

G'day Theo,

 

Its a 2 blade Revolution ... they are made up in Bundaberg.

 

It works very well in terms of performance but made the 160 feel like it had a turbine up front.

 

I also know a couple of guys that have the 3 blade prop on the 6 cylinder Jabs and they say the same.

 

Cheers

 

Jack

 

 

[Guest Decca]

Because I was concerned about the clarity of my post No.3 here, I've reworded it just in case Bruce or anyone else misunderstood the message.

 

Dec.

 

 

[Bruce Tuncks]

prop balance

 

Thanks Decca, I hadn't seen that site before. Its good.

 

I think the Jabiru prop is centered on the bolt-holes, and not on the central hole, so we need a slightly different jig shaft.

 

Getting back to dynamic balance, I know that car wheels can be in static balance but not dynamic, because it matters if you put the balance weights on the inside or outside rims, but this doesn't show on a static balance.

 

With a prop, this effect surely wouldn't count for much. Now if the dynamic balance also accounted for the spinner and crank etc, surely that would be good? But just how could this be done?

 

To complicate things more, I've been told that a prop is effectively unbalanced whenever the oncoming air is not perpendicular to the plane of rotation, now Jack has pointed out that any small pitch difference between blades will also give an unbalanced effect.

 

Hard subject........

 

Bruce

 

 

[jetjr]

Ive got a 3300 with Jab prop which seems to have ongoing issues with prop track.

 

Very sensitive to wind both in flight and on ground

 

If theres a X wind it can vibrate just like its out but later on in the flight, smooth as can be

 

Its actually the second new prop its had since I bought it and tracking always needs adjustment. First one had 1 tip about 7mm out from the other in relation to the hub, after short argument Jab replaced it.

 

I realise this is different to balance but Im reaching the conclusion the prop is varying as it is used or due to climatic changes

 

Anyone else see this trouble?

 

JR