balancing?

[geoffreywh]

I have just retorqued my 6ft wood prop. I took a lot of trouble getting the blades tracking evenly and was astonished at the reduction in (high speed/revs ) vibration.. Well. I thought, if some is good , more must be better? So I am looking at ways to balance the prop . Static only! Dynamic will be expensive and pointless as I have to retorque the prop quite often (4-6 times a year) ...I read that I can make a plug for the centre hole and suspend the prop. Then if it is out of balance (it will certainly be) WHAT do I use to correct the balance? Lead of course but what method to hold it?...Any help welcome....Geoff

 

 

[Guest aircraft1]

Dynamic is best and the retorque wont affect it if you do it properly, find someone who knows what they are doing and seek advise, many props are balanced with weights on the spinner, ithers with lead shot in the base but you NEED to know what your doing ! because planes dont go realy well when 1 blade departs !

 

 

[Bruce Robbins]

............. Then if it is out of balance (it will certainly be) WHAT do I use to correct the balance? Lead of course but what method to hold it?...Any help welcome....Geoff

Geoff,

 

You will not need any more than a few grams, certainly not any lead. One common method is a spray can of clear lacquer. Couple of coats on the light end till it just becomes the heavy end, let it dry, and you should be pretty close to the mark.

 

Bruce

 

 

[geoffreywh]

Ahhh as little as that? Only a few grams.......I will turn up a plug tonight and suspend it from the garage roof see what it looks like. Some tape stuck on will give me an idea of how much weight....Thanks...G

 

 

[geoffreywh]

OK I made up a balancing jig. Prop was perfect ! I have access to a flat table. The prop is dimensionally ALL OVER THE PLACE. One blade is 4 mm longer than the other. blade widths are different although the pitch seems ok. The prop is a Barry Bishton, looks almost unused. Although I think it is 30 years old. So where do I get a good (wood) prop? Are there ANY available in Australia? (70 x 50 ) Continental 0-200??? Thanks Geoff

 

 

[Smokey]

Geoff

 

I have a sweetappple, made by Richard Sweetapple in Qld, his props seem to have quite a good rep.

 

I seem to have misplaced his phone number but I know some contact details were posted here.

 

If he's still in business I'm sure he could make a prop to your requirements.

 

Mark

 

 

[Seal]

Just for interest, what sort of differences were you getting in blade chord at different stations along the span?

 

For a wooden prop to suit a Continental you could look here

 

http://www.sensenichprop.com/

 

These guys have been making props for Continentals since not long after the Wright brothers :big_grin:

 

 

[geoffreywh]

I had a long chat with Richard Sweetapple, He seems a really nice bloke and very knowledgeable. He is making me a new one!!!!

 

 

[geoffreywh]

I have since heard that the prop was hand made, and the length discrepancy is to do with balance...I have offered it for sale