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Whirlwind propeller shake

Posted: Tue Sep 26, 2017 1:43 pm
by Upsidedown
Hello everyone

I have a dozen flights on my version of the Laser type and things are progressing well. Running a Whirlwind 200AC in front of a straight valve ECI Titan IO360 with a Superior cold air intake. I had the prop dynamically balanced but I'm still getting a shake in the airframe. My guess is around 5-6Hz. This happens at 2440 rpm and changes a little but does not go away at lower rpm. Above that I would say the vibration is normal 4cyl. Prop is clocked at 10/4 as viewed from front at #1 TC. Looked for the obvious but nothing looks weird. Whirlwind says to balance it on the governor instead of on the pitch stops. Looking for more ideas to try when I'm back in town.

Thanks

Re: Whirlwind propeller shake

Posted: Mon Oct 02, 2017 5:12 pm
by Guicensoni
Same thing with me in a ww200c prop, have balanced dinamicaly last week but the vibration doesn't changes, thinking about engine mounts but not sure this is the point...

Re: Whirlwind propeller shake

Posted: Wed Oct 04, 2017 2:35 pm
by youngman1
Slightly concerning as I've just put down a deposit on a 200AC for my Laser. What engine mounts are you guys using?

Please let me know how you guys get on diagnosing these issues.

Many Thanks

Re: Whirlwind propeller shake

Posted: Thu Oct 05, 2017 12:36 am
by Upsidedown
I'm using the aerobatic dynafocal mounts that Aircraft Spruce sells, part #08-03600. I'm suspicious of the mounts as well. I may try another set that I have just to see if it changes anything.

Re: Whirlwind propeller shake

Posted: Thu Oct 05, 2017 8:59 am
by Guicensoni
Upsidedown wrote:
Thu Oct 05, 2017 12:36 am
I'm using the aerobatic dynafocal mounts that Aircraft Spruce sells, part #08-03600. I'm suspicious of the mounts as well. I may try another set that I have just to see if it changes anything.
Let us know the results, I use the same mount!!!

But in Brazil is a kick in the *** to get parts so if it works to you I’ll run for that!!

Re: Whirlwind propeller shake

Posted: Thu Oct 05, 2017 9:02 am
by Guicensoni
youngman1 wrote:
Wed Oct 04, 2017 2:35 pm
Slightly concerning as I've just put down a deposit on a 200AC for my Laser. What engine mounts are you guys using?

Please let me know how you guys get on diagnosing these issues.

Many Thanks
Beside this issue, The propellers are awesome and overpass the mt or any similar propeller performances.