Your video has really inspired me. One of the keys to problem solving is it to convert your impressions to numbers. You've just invented the "Duffy prop analysis method".

 

Measure the distance from you hangar door to your prop. Put mark on pavement, say at 20 ft. Put another mark at 30 ft. That's where your camera goes. Now, video your engine as well as others at those same locations. Calibrate your system by measuring the distance between the pleats on your hangar door.

 

Now go home, sit on the couch, get a beer. Fire up your videos. Find the worst deflection by using slow motion. Measure how far prop tip is from the hangar door pleat in background. So it's going to be around 1/4" on your video screen. We can convert that mathematically to actual tip deflection at prop! You've now measured deflection of 4 different aircraft and haven't lost a finger.

 

Then you just test your various ideas, trying to beat the best measurements you could find.

 

You could also use the video to measure prop diameter. Just in case one of the planes has different diameter. That would also prove how accurate this method is. I expect it would be unexpectedly accurate and meaningful.

 

Write up your test. This would be great one for Contact.

 

Indeed!

 

I’m all over this as there have been a few crank failures with the Corvair engine that MAY be related to this flutter anomaly.

CONTACT! readers might remember the recent article we published on this, and older readers might remember that in addition to being a huge Mazda fan, I’m rather into Corvair engines.

 

I’ve been keeping the Corvair e-mail list apprized of this thread and hopefully we’ll begin emulating this video with the Corvair.

 

Pat

Editor@ContactMagazine.com

 

BYW, the next issue of CONTACT! Magazine is at the printers and covers some pretty interesting ECU articles. Three total, including one by Steve Boese and his experience with the EC2, complete with adulations from Tracy.