[itizme]

Mount plate (wood) to fuse

Mount gear to plate

The Plate is now the victim instead of the fuse.

Pm me your email, I'll send ya pics

[BAMDFISHER]

Post your pictures here so that all of us can learn from your experiences.

[itizme]

Brian
SORRY
I forgot to show you on the Extra when you were here

The Idea comes from T.K., the gent I bought the Extra airframe from, where he got it I have no idea.

From the top inside the fuse there are 4 socket head cap screws through the normal fixtures that then secure a plate made from two pieces of laminated plywood. This is held in place by the four bolts that thread into blind nuts that are in turn holding the complete plate to the fuse. The finished plate being about 1/2" thick.

Drilled into the plate are 4 threaded inserts, these will pull out on a bad landing and the idea is that the gear separates from the fuse minimizing damage.

I have not flown this, have no experience with it but hope someone does and can comment further.

[spog]

I have had good results using nylon bolts, on much smaller models. I arrange the gear so that the force shears the bolt, versus popping the bolt head off. It is much easier to break the bolt head than to shear it.

[paulbipe]

Ya got my sympathies about pulling the landing gear off in thick grass. My original Sukhoi did that if I even touched the long grass at the end of the runway!!.

Plastic bolts do not work. I popped the heads off on a take-off on my Goldberg Ultimate!

Last year when I built the Sukhoi 26 (1/4 scale) I unashamedly copied the Carden approach and built some Oak rails into the motor box to spread the landing loads as far into the fuse as possible. The Carbon Fibre landing gear had to be cut in half as a canister and LG were attempting to occupy the same space..lol

Each half of the LG was attached to two rails with a single screw that was tapped into each rail.

I did one half of the LG with 6-32 machine screws and the other half with 4-40 screws. This combination flew for most of the season without a failure. At the end of the year I got caught a wet spot on the field just as I was touching down (thumping down was more like it) and the side that was held in place with the 4-40 screws pulled out. A shot of thick ca into the oak and the 4-40 was screwed back in and the ca allowed to set and I was flying in about 5 minutes. My LG is about an inch up into the fuse and the only damage was to the balsa covering over that side of the gear.

I am currently doing some "improvements to the plane and one of those will be to tap out the 4-40 for some 6-32 screws. One thing though..Do Not Use Tee Nuts to hold the screws in ...you want the oak threads to fail and allow the machine screw to pull out.

[tommy321]

Option 4:

Don't land so hard.