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  #1  
Old 04-20-2009, 09:32 PM
hudgin hudgin is offline
 
Join Date: Apr 2007
Location: Cedar Hill, Tx.
Posts: 159
Default Too many questions about Gear Stiffners

We are ready to install the gear stiffners so I would like to know what kind of recomendations you all have. I have read on the forums to install the fiberglass on the bias which makes sense. Question is do you do it in strips or go all the way from one end to the other covering the complete gear? How many layers? It seems like it will crack and break out any way. Am I right? The wood pieces show the gear is not straight. Do you do it with the weight on or off the gear? If so do you clamp the wood to meet (be flush with) the gear leg? Won't this cause corrosion under the fiberglass? Thanks in advance for your input.
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  #2  
Old 04-20-2009, 09:42 PM
Norman CYYJ Norman CYYJ is offline
 
Join Date: Feb 2005
Location: Victoria B.C.
Posts: 1,266
Default

I would not bother with the stiffeners. The last few planes I have not installed them, no difference was found in performance. If you need them install them later, save the labour and weight.
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  #3  
Old 04-20-2009, 09:53 PM
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newtech newtech is offline
 
Join Date: Mar 2006
Location: Evansville, Indiana
Posts: 661
Default

Quote:
Originally Posted by Norman CYYJ View Post
I would not bother with the stiffeners. The last few planes I have not installed them, no difference was found in performance. If you need them install them later, save the labour and weight.
I am also interested in the answer. I am putting the stiffeners on my RV-7A nose gear to help reduce the tendency to oscillate front to back. I have made my stiffeners out of Sitka Spruce and can use glass, carbon fiber or kevlar. I am tempted to use kevlar for the wrap.
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  #4  
Old 04-21-2009, 12:01 AM
gasman gasman is offline
 
Join Date: Mar 2007
Location: Sonoma County
Posts: 3,821
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No stiffeners at all on my 6A............ NO PROBLEMS....... mains are GOODYEARS and nosewheel is GROVE.
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  #5  
Old 04-21-2009, 09:22 AM
Norman CYYJ Norman CYYJ is offline
 
Join Date: Feb 2005
Location: Victoria B.C.
Posts: 1,266
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If you use Kevlar do a real neat job of it because it is next to impossible to sand!
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  #6  
Old 04-21-2009, 01:51 PM
n601sc n601sc is offline
 
Join Date: Jan 2005
Location: Dayton, OH
Posts: 19
Default Try oak molding a strapping tape for gear shimmy

For the first year or so with my RV-6, I operated with no damping device on the gear legs and, from time to time, experienced rather severe gear shimmy (forward and aft movement of the wheels at roughly 2 or 3 Hz at taxi speeds). Enough shaking to know, ?this is not good?. A change to Michelin tires appeared to help somewhat, but not cure the problem. I also experimented with varying inflation pressure, but I was not persistent enough with the ?test? to establish a best pressure. The fact that the problem would come and go didn?t help matters.

I did, however, have some good success by (literally) taping oak strips to the LE of the legs. To be specific, I visited my local Lowes, selected the most dense length of oak ?? cove molding (roughly the same radius as the steel leg), cut two pieces to 90% the length of the leg(s), then with 1? fiber reinforced strapping tape, bound the wood to the LE of the leg(s). Starting at the top, I just ran the roll of tape down like a candy-cane with a slight overlap with each turn. I used a fair amount of tension and tried to keep the tape smoothly wrapped all the way around. Very inexpensive, and should the need arise to inspect the legs for corrosion, simply remove the old tape and replace it with new. So far after about 2.5 years 200+ hours later, the tape is still looking pretty good and only rarely will the shimmy gremlin reappear. Note, with this size molding, I was able to still slip the fairing over the legs without issue.
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  #7  
Old 04-22-2009, 05:58 PM
Bavafa Bavafa is offline
 
Join Date: Oct 2007
Location: Sacramento, CA
Posts: 3,351
Default best to wait and add them as you need them

I was at the debating to install on my gear legs and after some research decided not to and wait to see if I will have shimming issue. It is not much of a problem to add them later but if you do, you will never know if you needed them or not and will carry the extra weight all the time.
Well, I started flying about a month ago and have already flown my time off and have not had any issues so far. If you do decide to add them to the front nose gear, be careful as not to do it too much. The front gear leg is tapered in such a way to take the load and if you stiffen it too much, most of the force will go to the engine mount and it could fail there. Vans advises against it unless you have serious shimming on the nose gear.

My 2 cents
Good luck
Mehrdad
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  #8  
Old 04-22-2009, 06:34 PM
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L.Adamson L.Adamson is offline
 
Join Date: Apr 2005
Location: KSLC
Posts: 4,021
Default My shimmy experience

When I bought my 6A kit, it was the norm to fiberglass stiffeners to the legs. But I didn't get it flying until last year; and in the meantime, Van's came up with the fiberglass fairings and not installing stiffeners as a standard practice.

So I do have a 6A without stiffeners. On the very first landing, I let the nose down to fast, and got an intense shimmy. I reset the breakout force, and haven't had no further shimmy like that in the near 70 hours that's on the plane now. But I do make it a practice to keep the weight off the nose gear as much as possible. Sometimes, I'll get a slight shimmy while taxiing after landing, and just throttle back to get rid of it. It's just a very small percentage of landings, that it happens. Therefor, I see no reason to add the weight of stiffeners at this time.

L.Adamson --- RV6A
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  #9  
Old 04-25-2009, 07:59 PM
rv6srb rv6srb is offline
 
Join Date: Jun 2008
Location: Humble,TX
Posts: 17
Default

260 hours on my rv-6. Never had a shimmy. Good landing or bad:-) Grass and hardsurface.
No stiffeners. I know of at least one builder that filled the gear leg fairing with expandable foam once it was installed. Don't know how it worked.

My 1/2 cent worth, Steve
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  #10  
Old 04-25-2009, 09:51 PM
nucleus nucleus is offline
 
Join Date: Sep 2006
Location: Bozeman, Montana
Posts: 858
Exclamation Expanded Foam in Gear Fairing BAD

Expanding foam in the fairings have been known to hold water and cause gear leg corrosion due to retained H2O.

Hans
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