Hi, I'm David Mack. In 2006, I decided to build my own Van's Aircraft RV-7 200+ mph two seat homebuilt aluminum airplane and this is a log of the experience.

Friday December 12, 2025
Dynamic Prop Ballancing

Today, I flew out to KAKO (Akron, CO) to Redline Propeller to have my propeller dynamically balanced. Dan installed a vibration sensor on top of the engine.

And then an optical sensor with some reflective tape on one blade of the prop.

My prop tested at 0.35 IPS of vibration at 2,000 RPM, which is greater than the 0.2 limit, so it was a good idea to do this.

The computer figures out where to add weight and how much is needed. After a couple of rounds of testing, Dan determined that this was the spot for the weight. We removed the spinner and he added a hole to the backplate and countersunk it.

Then he added this screw, washers, and nut to the hole. Afterwards, we reinstalled the spinner. Centrifugal force will keep it all pinned against the spinner.

It made a big difference. The IPS are now 0.04 and the engine/prop combo feels significantly smoother than it did before. Well worth the money!

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