Dynamic Propeller Balancing

[rwaltman]

... I was amazed how much smoother my engine was after dynamc balancing.

Checking the available options:

(a) RPX's Dynavive - $1495
http://www.rpxtech.com/rpxweb/default.asp

(b) DSS's Personal Microbalancer - No price information
(Asked and shall receive, but not yet - Reported to be ~$2700)
http://www.dssmicro.com/products/prod_mb_main.htm
[Added: received a quote - a full kit is $2694]

(c) Smart Avionics PB-3 - 495 British Pounds, ~$790 (plus Android device)
http://www.smartavionics.com/pb3/pb3.html

(d) Don Cheapote - $1
From a post in www.homebuiltairplanes.com

"Hi guys:
Let me tell you how I dynamically balanced my prop for about $1.
First I painted the outer edge of my prop flange black.
Then I got a stiff rod (not from reading a magazine) that was about 5 ft long, and taped a piece of chalk at the end.
Then I tied the tail of the plane to a strong post, set the brakes, chocked the wheels and ran the engine up to 2000 rpm.
Then I stood next to the flange, a couple of feet behind the prop, and moved the chalk closer, and closer to the flange until it just barely touched the flange.
Then I shut down the engine, and looked at the flange. There were chalk marks on one side of the flange, so I figured they must be on the heavy side, and pulling the flange over to contact the chalk, thanks to the give of the engine mounts.
I added weight to the opposite side, and solved my vibration problem.
If you decide to try this method be very careful, and also remove the cowling, so you can stand farther back from the prop. Also it would be good to put a c-clamp in an area within 2 feet of the flange, that you can put the stick through, and it will brace the stick, otherwise the prop blast makes it hard to hold the stick steady.
I did this on a VW engine, so if you have a lot more power, it may be difficult to stand steady in the prop blast without some kind of brace.

Good luck.
StarJar"

Still looking for a DIY project. Any other thing I should consider?

Roberto.

[napierm]

Checking the available options:

Good luck.
StarJar"[/INDENT]Still looking for a DIY project. Any other thing I should consider?

Roberto.

I will frankly be amazed if dynamic balancing is required on that powerfin. If a tube through the prop didn't show anything grossly off then balance is not the source of the massive vibration you are seeing. What does work are the "balance balls" in a ring that can be bolted on behind the prop. It takes out minor vibrations very well.

I don't know what your problem is but don't think that is it.

FWIW,

Mark

[rwaltman]

... balance is not the source of the massive vibration you are seeing... I don't know what your problem is but don't think that is it.

Agree, this is for future improvements, after I get over the current problems.
I am meeting this Saturday with a Rotax guy to check the carburetors.
Will report back.

Roberto.