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Attaching gear stiffeners

cyrus

Well Known Member
Has anybody found a disadvantage or advantage to one type of epoxy system over another for attaching the wood gear leg stiffeners?

I was leaning towards West Systems since they're easier to work with and have pumps, and I'm new to glass work.

Reading the forums, many people suggest they're not the strongest, but am unsure how strong this needs to be. Since the spring steel gear flexes quite a bit, we would want the glass and wood to stay firmly attached.

Aeropoxy, EZ Poxy?

Also, which 2" tape from spruce would be recommended? In the Construction Manual it suggests 2-3" 9oz. I don't see this specifically at Spruce, unless i'm missing something.

http://www.aircraftspruce.com/catalog/cmpages/etapes.php?clickkey=18109

Appreciate the help!
 
Has anybody found a disadvantage or advantage to one type of epoxy system over another for attaching the wood gear leg stiffeners?

I was leaning towards West Systems since they're easier to work with and have pumps, and I'm new to glass work.

Reading the forums, many people suggest they're not the strongest, but am unsure how strong this needs to be. Since the spring steel gear flexes quite a bit, we would want the glass and wood to stay firmly attached.

Aeropoxy, EZ Poxy?

Also, which 2" tape from spruce would be recommended? In the Construction Manual it suggests 2-3" 9oz. I don't see this specifically at Spruce, unless i'm missing something.

http://www.aircraftspruce.com/catalog/cmpages/etapes.php?clickkey=18109

Appreciate the help!

West Systems and the glass tape from spruce would work fine.

May I ask if you have checked all the factors that can cause leg shimmy?
Out of balance tires/wheels. Out of round / flat spotted tires. Mis-aligned axles. etc
 
Thanks for the reply. During my annual I did change tire with the shimmy and and had the wheel professionally balanced. I also used grease plates and noticed the pilot side may have a slight toe out compared to the passenger side but have not flown it yet with the new wheel.

I just figured while I was doing my annual I might as well put the stiffeners on. The people (ive talked to) that have them seem to prefer the characteristics of the stiffer landing gear.
 
thanks cj, that's valuable info and certainly makes me curious. Is the corrosion is a common occurrence? I'm wondering if you applied the epoxy and wood to a bare metal gear leg or was it a painted one. I was told to sand the paint off the gear leg as the bond would only be as strong as the paint underneath.
 
It is a good idea to corrosion proof the gearlegs with paint or whatever before epoxying the stiffeners in place. I actually tried the stiffeners using only three nylon tiedown straps to hold them in place and they still worked fine. The fiberglas and epoxy don't necessarily have to bond to the gearleg. The mixture just holds the stiffener in place and provices more adequate stiffening. Again, follow instructions as Van outlined.
 
I used heavy duty zip ties...

I used about 10 heavy duty zip ties to attach mine... 2 closely spaced at the top and bottom and the rest evenly spaced more or less. Provides for a fully coupled wood / metal composite to dampen out transient vibrations. I have had them on and off a few times but find that they make a small beneficial improvement.
 
Strapping tape

I didn't use wood stiffners (SCH 40 PVC cut in half) and attached
them with 3M 3/4" strapping tape wrapped around the stiffner and leg.
Easy to remove (adhesive cleanup can be a pain). Brake line runs inside
stiffner. Easy, cheap and fast.
 
So i ended up adding the stiffeners and they're amazing. My wheel landings are much smoother, no bounce, and although i did change the tire, all wheel shimmy is gone. For me, it's one of the best things i've done for anyone who's thinking about it.
 
I bonded my stiffeners on with ProSeal then added a couple wraps of 3" fiberglass tape at the top, bottom, and middle. Worked well for me.
 
From my understanding, It's imperative to mount them without a load. I put some carriage bolts into the tie downs and jacked both wings up until the load was off.

**** TIE DOWN THE TAIL WITH WEIGHTS!!

I foolishly didn't think about where the C of G was and although I was slow and cautious with extra hands, I saw how it could have been nasty. What an unfortunate way to claim a prop strike, lol.

I did a double pass, first down at roughly a 45 degree angle and then let it dry and made sure the bubbles were pressed out. Then the next day went back and did it the opposite way so it was cross hatched. I installed them on the leading edge so the break line could remain at the trailing edge.

One thing to be careful of if you have a gear fairing is make sure the angle you install the stiffener is where the fairing wants to be, or it will have a tough time lining up, and having the pieces that attach to the cowling line up as well.

Was a great project and well worth the time! Have fun :)
 
I didn't use wood stiffners (SCH 40 PVC cut in half) and attached
them with 3M 3/4" strapping tape wrapped around the stiffner and leg.
Easy to remove (adhesive cleanup can be a pain). Brake line runs inside
stiffner. Easy, cheap and fast.


It would be interesting to see your solution with the "SCH 40 PVC". I was ordering Flyboys wooden stiffeners but they needed $52 to ship them to Sweden so I'm looking for some cheaper solution. Could you send a photo.
 
Attached using Gaffers Tape

Just added leg stiffeners to my RV-7, and wow what a great improvement. Improved the landing and then the run out through all speeds. This really greatly improved the RV-7 handling on the ground.

Bottom line is I should have done it sooner.

Method of attaching stiffeners:
Gaffers Tape wrapping parallel strips going down the leg and back up (not in a spiral).
 
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