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Prop Balancing - SE USA

Kyle Boatright

Well Known Member
Over the 14 years (!) I've had my RV-6, I've made many modifications - some small, some not-so-small. Occasionally, one of the modifications results in an unintended consequence. Recently, a starter replacement (Prestolite -> Skytec) necessitated the installation of a steel flywheel weight to keep the CG where I wanted it. Unfortunately, the steel weight significantly changed the vibration level in the airplane. Presumably the flywheel weight was machined slightly "off" or the attach hardware had a little variation in it. In any case, what had been a very smooth running engine/prop gained a noticeable vibration.

So I began looking for a shop to perform a dynamic balance on the prop, and ultimately I found VAF Member/Moderator Brian Wallis here in Atlanta who could do the job. So it was a brief flight over to his home field for the prop balance a couple of weekends ago to get everything balanced.

The process was simple. Remove the cowl, chock the airplane, install a piece of reflective tape on a prop blade, and install sensors to measure prop position and vibration. Then run-up the engine with Brian monitoring things on a DynaVibe prop balancer. After that, he added a couple of weights, re-tested, and we were done. The vibration level went from 0.4 IPS to 0.04 IPS in one swell foop*. The difference is very noticeable in flight. I'm back to a very smooth running engine/prop combination which makes for a nicer flying experience.

Highly recommended (prop balancing in general and Brian's work specifically).
 
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great guy

He did my prop two weeks ago and I'm still amazed at how much different it flies.

Brian get ur transponder fixed and let's go catch some Red's.
 
Kyle, thanks for posting this. I've been wanting to do this locally and wanted to find someone that came recommended.... and better, a VAF member/moderator.

I will be reaching out to Brian.

Thank you
Amir
 
Over the 14 years (!) I've had my RV-6, I've made many modifications - some small, some not-so-small. Occasionally, one of the modifications results in an unintended consequence. Recently, a starter replacement (Prestolite -> Skytec) necessitated the installation of a steel flywheel weight to keep the CG where I wanted it. Unfortunately, the steel weight significantly changed the vibration level in the airplane. Presumably the flywheel weight was machined slightly "off" or the attach hardware had a little variation in it. In any case, what had been a very smooth running engine/prop gained a noticeable vibration.

So I began looking for a shop to perform a dynamic balance on the prop, and ultimately I found VAF Member/Moderator Brian Wallis here in Atlanta who could do the job. So it was a brief flight over to his home field for the prop balance a couple of weekends ago to get everything balanced.

The process was simple. Remove the cowl, chock the airplane, install a piece of reflective tape on a prop blade, and install sensors to measure prop position and vibration. Then run-up the engine with Brian monitoring things on a DynaVibe prop balancer. After that, he added a couple of weights, re-tested, and we were done. The vibration level went from 0.4 IPS to 0.04 IPS in one swell foop*. The difference is very noticeable in flight. I'm back to a very smooth running engine/prop combination which makes for a nicer flying experience.

Highly recommended (prop balancing in general and Brian's work specifically).

Thank you very much for the compliment sir. Kyle's aircraft is SO nice. If your airplane is gone... it's not me but it WILL be back in an hour or so. Kyle was a unique customer for me in that he had a flywheel weight installed. That is not unheard of but made me painfully aware that I did not have any hardware in stock that was as long or longer than the bolts he was using on his flywheel to secure the weight (simply because it is rare to have a customer with a flywheel weight). If I needed to add a bunch of weight, I would probably have to do a split solution (which the machine will do for you) just to have enough threads to be legal. Fortunately we did not have to split the solution and he is a happy and legal camper. When you place a large machined weight on the crank, no matter how precise the CNC machine is, the weight will be slightly off center due to localized weight differences in the metal. All credit goes to Dynavibe for sure. Thank you guys for the good words!!!!
Best,
Brian
 
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