The things we learn... Wheel Shimmy

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captain_john
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The things we learn... Wheel Shimmy

Post by captain_john »

Soooooo... Billy's Six has been having a main wheel shimmy on both main wheel for about the last 10 hours. The plane has 110 hours on it and it has gotten really bad.

We decided to look into it a bit more deeply. We balanced the tires using tape-a-weights and it improved a bit. It took a fair amount of weight. Probably about 3-4" of weights on each wheel!

After a test flight, I saw only a slight improvement. The shimmy was the worst between 14-34 knots either decelerating or accelerating.

The tires are out of round and I was wondering if that was contributing to the problem in any way.

Billy suggested lowering tire pressure. We brought the tires down to about 26 lbs and it was like MAGIC! ALL the shimmy was gone!

I guess that the additional rolling friction with the lower tire pressure reduces the ability of the wheel to speed up and oscillate in a fore and aft motion.

Perhaps when the tires were newer and less egg shaped this didn't matter as much but now that they are older...

Soooo, if this helps anyone out there... That is why we are here!

I am sure this isn't anything new but it is worth stating again.

I hope it helps you!

:) CJ
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speedpants
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Post by speedpants »

Next time consult your local A/P IA, I bet he would of suggested trying that 9 hours ago ;)
The best aircraft mechanic is one you only see once a year

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painless
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Post by painless »

Also watch the wear on the kit supplied tires CJ. I started to get shimmy and did all the things you did, short of making gear leg stiffeners. Replaced the tires with monster retreads from Desser, and couldn't believe the difference.

I would mostly get shimmy on roll out from landing. I suppose the improvement could be from the fact that all my landings are greasers....... :wink:
Jeff Orear
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Bill H
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Post by Bill H »

He has been to busy celebrating his birth day and hanging out with his girlfriend :mrgreen:

Bill H
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Post by Bill H »

new tires are on the list . going with the monster retreads also. I think they will help solve the problem even know the problem is gone for now

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Post by captain_john »

Bill H wrote:He has been to busy celebrating his birth day and hanging out with his girlfriend :mrgreen:
DOH!!! Good one Billleeeee!!!

hahaha

Speedpants who??? Oh yah! That guy who used to drink my Hangar 5 beers!?!

:lol:

Billy, are you gonna need that knife back?

:mrgreen: CJ

BTW guys... I am ready to have you guys back over and do some epoxying for me now!

:wink:
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It's all over but the flying! 800+ hours in only 3 years!

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captain_john
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Post by captain_john »

painless wrote:Also watch the wear on the kit supplied tires CJ. I started to get shimmy and did all the things you did, short of making gear leg stiffeners. Replaced the tires with monster retreads from Desser, and couldn't believe the difference.

I would mostly get shimmy on roll out from landing. I suppose the improvement could be from the fact that all my landings are greasers....... :wink:
Jeff, I just don't think those wooden stiffeners are really necessary.

I agree...

The retreads are very popular! Good call!

:) CJ
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It's all over but the flying! 800+ hours in only 3 years!

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painless
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Post by painless »

captain_john wrote:
Jeff, I just don't think those wooden stiffeners are really necessary.

I agree. Never made/installed any.

Happy birthday, and give my regards to Michelle. I still say she's a Saint for putting up with you..... :P
Jeff Orear
RV6A N782P
Hatz Classic, Welding fuselage
Hatz build log. http://websites.Expercraft.com/painless
Peshtigo, WI

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captain_john
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Post by captain_john »

painless wrote:
captain_john wrote:
Jeff, I just don't think those wooden stiffeners are really necessary.

I agree. Never made/installed any.

Happy birthday, and give my regards to Michelle. I still say she's a Saint for putting up with you..... :P
Nooo... it's Speedpants' birthday! ...or it was.

He has been kinda scarce since he has been getting regular tune ups!

...and yes, I have no idea why Michele hangs around with me either! hahaha

I will tell her you said hello, though!

:) CJ
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Garmin G3X with VP-X & a TMX-IO-360 with G3i
It's all over but the flying! 800+ hours in only 3 years!

Vlad
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Post by Vlad »

captain_john wrote:



...and yes, I have no idea why Michele hangs around with me either! hahaha



Because you live in the boonies and Michele has no choice. Tell her come to NY :lol:




Shimmy wise last week I've seen Richie out of Spadaro was glassing stiffeners to his 6 legs. :mrgreen:
RV-9A N666BK flying 4,500+ hours since 2011

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