tipstall 131

Hi guys,

I've made some landing gear for a 1/2A project of mine out if hardware store aluminium. The Al is just too soft and bends on every landing (or "arrival"). Is there a way to temper the Al as you do with steel to harden it some and give it some spring qualities?

I would appreciate any and all answers!

JRFisher

No can do. You have to buy it that way.

MinnFlyer

My Feedback: (4)

It CAN be done, but it's a MUCH more involved process than steel.

Plus, like steel, there are different types of aluminum alloys and each will react differently to heat.

jester_s1

You can make some cross braces out of wire to stiffen the gear up a bit. It won't be springy, but it will resist bending.

frequent flyer

My Feedback: (6)

I make gear for even heavy Giant Scale planes they never bend. I use 6061 T6 alum. I even heat it to make the bends. it just regains it temper after it cools off.

Sandmann_AU

I've had a plane with gear like that. I drilled a hole in each leg about half way along it, and used some fishing trace wire to make a "brace". They would still bend but it'd take a lot more effort and the bend was much lower down the legs.

tipstall 131

Thanks everyone for all your replies. I guess that I'll have to go the piano wire route on this one. I just dont like the look of piano wire gear that much. Oh well...

Thanks again all!

Lnewqban

tipstall 131,

Try heating up and then insulate it from air, so it cools down as slow as possible.
If the aluminum is the proper alloy, it will work.

If not, you could glue (with any metal glue or epoxy) a semi-gear just under this one, overlapping only the critical bending zone near the fuselage.

tipstall 131

I think I dont have the right alloy for the job. I did see a tutorial on how to make composite gear. Thanks for the suggestion though.

Lnewqban

The right alloy for the job is described here:

http://www.rcuniverse.com/forum/m_91...tm.htm#9147087

You are welcome; bst luck!

TomBates

I don't know how to temper Aluminum but here's a company that sells Main landing gear in several different lengths that aretempered. Give them a try. http://www.radicalrc.com/category/Main-Gear-352 Good luck.

Tom

jaka

Hi!
No!
Use correct aircraft aluminum like T-6 6061 (you bend it cold ) or better T?-2324!

Campy

My Feedback: (1)

Use 6061 (T6) aluminum for your landing gear. DO NOT try to bend it cold - it will fracture internally.

If you go to a metal shop and ask nicely, frequently they will give you some "cut offs" for free (cut offs range from a couple of inches long to about 20")

You will need the following equipment: A vise, A BLACK magic marker, a propane torch and a couple of pieces of 2x4.

To bend T6 aluminum mark where your bends are going to be using a magic marker. Put the aluminum in the vise and heat JUST the bend mark until the mark turns BROWN.

Now take your pieces of 2x4 and use them to bend the aluminum (Keeps the aluminum nice and straight and you don't get any tool marks in the metal).

When you are done with all your bends take the LG and set it aside for a few days. After about 5 days T6 aluminum will reharden itself to somewhere between a T4 - T5.

Do not drill your axle holes until after the metal has rehardened as you can easily change your bends while drilling the holes (don't ask how I know this)

I have used this procedure on 11 lb planes without a landing gear failure or having them "spread".

tipstall 131

Wow Campy thanks!

I am going to go to a shop that sells engineering supplies close by, maybe I'll get lucky. Thanks for the good info, just wonder how you found out that the temp is just right when the ink turns brown.

Ed Smith

It is called "learning from others"

Ed S

StevieM

piano wire doubler, strapped to underside of gear with saddle clamps.
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have done this with 9lb cap, and 8lb stearman using 8swg......never needed to straighten alloy again!!
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...obviously select correct swg for your application.....it will work !!!
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good luck, steve

hugger-4641

My Feedback: (6)

If you really want or need to, you can temper 6061 to T6 again by putting it in an oven at 350F for about 8hrs then turn the oven off and let it cool off on its own for a few hours.

Sandmann_AU

Of course, after paying for the power to run an oven at 350F for 8 hours it'd probably be cheaper to just buy an appropriate piece of alloy in the first place.

jaka

Hi!
2-4mm T6-6061 will bend just fine cold. But never bend against a sharp edge in a wise!

tipstall 131

Will do, thanks!

Lnewqban

A last and very good idea here:

LANDING GEAR REINFORCEMENT STANDOFFS

http://www.bennettbuilt.com/page7.htm

Campy

My Feedback: (1)

The person that told me how to bend T6 told me about the black magic marker and having it turn brown.

rravetrainshop

My Feedback: (2)

I built some landing gear out of an old aluminum street sign I dont know the temper of this type of metal but it is plenty stout . I am putting  it on a 1/5 scale bird with a total finished weight of 25 - 32 lbs. On a floor scale I can push down (straight or on an angle ) 40 lbs + with no ill effects. YET to be field tested!!!