I wasn't happy with my prop's balance on my -10, so...

[pierre smith]

...I got hold of Brian Wallis in Atlanta and he came by today and smoothed things out. First, he mounted a vibration sensor on the lifting eye of the engine, and a laser camera to the front left valve cover, as the picture shows. The laser bounces off a strip of reflective tape that he stuck on the face of the prop:


He then ran the wires to the control panel along the side of the airplane and we taped them down before running the engine:

Then, with him at the wingtip, I started the engine and ran it up to cruise...2400 RPM and the imbalance was 0.30 IPS or thereabouts. IPS, or Inches per Second, is a value that gets smaller as the engine/prop gets closer to being balanced, the smaller the number, the better.



We had to run it four times and got closer each time until it was in the 0.04 IPS range...much smoother than before.

His unit tells you where to add weight, as in 230 degrees from the top of the engine in the direction of prop rotation. A good balance will save your accessories from vibration damage, cracked baffling, etc.

In the end, we ended up adding 28 grams to the ring gear with an AD4 bolt, three fender washers and a nut, since the prop had a rock strike and the indentation at the tip lost some weight earlier in its life.

Best.

[DEWATSON]

Pierre,

Brian is a great fellow and I intend to get him to balance mine once I get it airworthy. I need to spend the disposable money on other things right now, but I'll certainly get Brian to smooth it out once it is flying.

Also, thanks for all of your input here.

David Watson
49FD

[scard]

I'm right behind you. I'm doing mine this weekend again, mostly due to a nick as well.

[brianwallis]

What a DAY!!! This prop balancing machine is quite the machine! I guess it was luck but I got Rich's Cessna 188 down to 0.00 IPS. The rest of the airplanes this week have been reading some pretty good vibrations! 1.2 is the limit and I've been getting some planes in at 0.9 and 0.8 for the first run. I've been able to get them down to about the 0.03 range after several runs. Just about each engine airframe combination is different on how you mount the camera and the accelerometer so it's been quite the exercise in adaptation. I'm looking forward to some really smooth RV's. When I mount the accelerometer and the camera, I do not want to remove a case half bolt if I can help it. The 188's were straight forward, one had a Eng hook to mount to, the second required an L bracket, the Cirrus required an L bracket because the top was covered with large tubes, the RV10 required an L bracket and the camera on the side, the turbine Cropduster required a camera on an L bracket with the accel mounted on a 90 deg bracket... Next time, he will get a much longer bracket because of the heat. So far I have been successful in not having to remove any case bolts... I have come up with several ways to mount the gear without removing a case half bolt on every customer so far. I hope to continue that trend......

Best
Brian Wallis
ps.... somebody better fess up to convincing DEWATSON (David) that I'm a good guy..... you guys should be ashamed of yourselves!

[AX-O]

Originally Posted by brianwallis

Just about each engine airframe combination is different on how you mount the camera and the accelerometer so it's been quite the exercise in adaptation.

This is what I have been using. It has worked on every single aircraft so far. For more pics go to http://www.alvarez-aviation.com/Inst...n_Pictures.htm

[rv8guy]

Brian strikes again! We got Miss Sue down to .01, and she really feels smooooth.

Thanks Brian another plug for Wallis Aviation, great job

not only balanced the prop, but had a great time as well

[RV10inOz]

How do I get him to Brisbane!

Any Oz folk know who does this locally?

DB

[brianwallis]

Is a round trip ticket? Don't think I won't! I love to travel! Marshall is a very gracious gentleman and has a BEAUTIFUL RV-8.
Best
Brian Wallis

[RV10inOz]

Sounds like fun.....you got big tanks in your machine!

I will email you in a minute! I have my hands on thses sorts of devices so I could probably rig one up here. Don't think it will ruin your customer base too much!

[AX-O]

Brian, nice job