hi i am making a pair of aluminumm landing gear from a 1/8 inch thick by 1 inch wide flat stock any tricks to getting nice tight bends? also can aluminum be heated to bend easier? and in what ways can the modeler weld aluminum? thanks guys

Aluminum is best bent in what's called a brake. It's basically a narrow table which hold one side of what your bending flat on the table. In the middle, right at the edge of the clamping area, the table breaks and naturally bends the stock. These are very expensive pieces of industrial equipment, but is the best thing if you can get access to one. Now what you also could do, is clamp your stock in a vise. Square it up so your bend is square. Take some think flat stock made from steel, and even thincker if made from aluminum, or anything else that is rigid and runs the full length of what is protruding from your vise. Clamp this material on both sides of what is protruding tightly, and make a bend. The material that you clamp onto your stock that your bending needs to be as close as possible to the vise to make the tightest bend. The Brake, however, is the only way to make what you would see in a hobbly store. Heating is not going to help, and you said you were only dealing with 1/8 inch aluminum. There are several ways to weld aluminum, the cleanest and the best way is with a TIG (Tungsten Inert Gas) Welding Machine. YOu can also use a wire feed machine with alminum welding wire, but this way is usually used with long and larger quatities of welding is required. I've made several sets of aluminum landing gear, but I've always had the brake, and anything else I've needed as I am a Machinist. Sometimes I'm caught outside the shop and need something awfully bad and have to improvise. The success is always directly related to how bad the need is to have it

You have to be careful on how tight a bend you put in you alum. too tight and it will crack, how tight? depends on the type of alum.
The bend should be across the grain if possible. I have used a trick I read somewhere: take 2 short lengths of angle iron and put the alum. between them and squeeze it together in a vice makes a nice bend. This site has some info on bend radius
www.engineersedge.com

Ok guys, here is what I do, and I have made many, many gears from 6061-T6 plate in 1/8, 3/32 and 1/4" up to 4 inches wide.

First, lay out your gear on the plate and cut to shape. Mark where you want the bends to be, and prepare yourself a means to make a good straight bend (large vise, a couple pieces of wood and clamps, etc - I assume hobbiests DONT have a brake handy!). Now the neat part! Take a plain old black magic marker, and put a line on the bend point. Now take a propane torch, and heat the area of the bend untill the marker line turns brown. Yes, it will go from black to light brown allmost instantly when the temp hits a certain point. It is at this point the aluminum will EASILY bend, but will not fracture or crack, and is not yet at the melting point. Position in the vise and make your bend. Then allow to cool, and carry on.

This trick does really work, it is easy, and accurate to get to the correct temp to bend. And yes, the heating does make the bending MUCH easier. Try it and you wont ever do it any other way!

Andrew Coholic

Sorry Andrew, I beg to differ. I too have bent plenty of ali U/C systems in my day. The last thing I would do is apply any heat to the stuff.

My rule of thumb is to cold bend the 6061 -T6 around a radius equal to the material thickness. To arrive at a former it is a relatively quick and easy job to file the required radius on the edge of a piece of scrap material of the same thickness.

Support the item to be bent firmly in the vise and clamp a solid piece of steel or similar on the leg to be bent to prevent unsightly dents that will occur if you beat the material direct.

If you try and bend it around a sharp edge you will break it for sure. Maybe not the first bend - more lilkely the last one! Sods law.

This bending system still applies using material up to 1/4" thick. It just needs a super heavy vise and a big hammer!

Good Luck

Alan W

Hey, do what YOU want, but you cant pound the crap out of aluminum without causing damage. Heating on the other hand, especially a good alloy like 6061-T6 will allow bending easily without fracturing, and still gives the originals' strength and elasticity. I have done it many times and it works so what can I say? I got this tip from a fellow that makes gear for sale, many many gears later it works.

If you have not tried it, dont knock it. I have tried using the "force" method and bending a 4" wide 1/4" plate of alloy is a job needing a 20 lb sledge, not exactly what I would call easy, and you will fracture the metal.

Andrew Coholic

I bend mine from a brake made from a large hinge easily purchased from a hardware store and a few pieces of alluminum to fabricate the other parts for a home made brake. I ALWAYS HEAT THE ALUMINUM with a propane torch and it hasnt hurt any of the gears yet! Try this method and see for yourselves.

Hi dickj and all, I have a propane torch on my shopping list but I am not sure what type to get. Which would you recommend ? Is it possible to post a pic so that I can get a better idea ? Thanks a zillion............

just buy the 4 dollar propane bottle and the cheapest torch at Home Depot thats all you need. They also make a automatic lighter kind for around 28 dollars. Dont heat the material too hot. Just heat enough to where pressure on the metal bends it quite easily and then let it cool. IT works great.