Pete, I am glad you made it back to Leander! I missed you at Oshkosh. I walked and walked and walked, by Thursday this Old Man had had enough!
Weather/Thermals/Wind
Mechanical
Pete, I am glad you made it back to Leander! I missed you at Oshkosh. I walked and walked and walked, by Thursday this Old Man had had enough!
Paul Zimmermann
LSRM-A
Garland, Texas
Paul, I stopped by, but you were out. I loved your plane. I want one when I grow up.
Pete
Leander, TX
Model III SN 1000
912
Grove
If you think the vibrations come at certain RPM, check you engine mount.
Sometimes it is hard to find the source of vibrations.
I will try the half flap trick. After some thought, I'm going to also try running the engine at various RPMs on the ground and see if I can find a range that excites some movement. With the damping from sitting on the gear it shouldn't shake as much but I think I'd observe something. If there is a consistent RPM range, I'll put a yellow arc on the tach.
And I will check the motor mount, fasteners etc again. Maybe the rubber bushings have gone soft. Thanks for all the advice, folks.
Haven't found any problems w engine mount, etc, fixed all looseness in the control system - but I think I have a harmonic with the engine/prop at about 3600 - 3800 RPM. Ground runs in that range cause some wing tip movement. The wiggle looks a lot less severe at 0 feet than 3000! I'm sure that's all perception on my part. My changing RPM and airspeed stopping it makes sense, low airspeed occurrence is when the RPM would be that low, and all I really needed to do was move the throttle. Looks like I need a yellow line on the tach. I'm running an HKS with the lower reduction ratio (2.47:1, I think) and an IVO 2 blade. I don't think that's a common combo, so that's probably why others haven't seen it..
Cheers,
Larry