My frame plan

[rasp]

i plan on using aluminum 6061, all parts 2" square tube 1/4" wall and the tounge would be 3" square 1/4" wall. this would be a 5 wide tear. what do you all think.

[Nitetimes]

I think that's gonna be Expensive but otherwise I see no reason it won't work if that's what you really want. I am not a big fan of aluminum frames, too much drilling and bolting to attach all the steel parts that normally get welded on. Generally the weight savings is not enough to justify the cost difference if you build it as strong as steel is in much thinner material. Then again if ya already have the material or access to it cheap ya might as well use it. Do what you wanna not what someone else tells you to do.


BTW - as far as the frame layout goes, it looks fine!

[angib]

rasp,

6061 is a strong grade of loomium - tensile yield is about the same as mild steel - but I still think I'm gonna apply my usual rule of thumb for aluminum, to assume it's a third as strong as mild steel. Luckily for my theory, this also exactly matches the fracture strength given for this alloy over 500 million cycles - so even if you drive it over washboard roads like Dave N, you shouldn't get cracking at the welds.

An easy way to equate your aluminum sections to steel is to divide the thickness by 3, so this would give you a 2" x 2" x 16g frame and a 3" x 3" x 16g tongue. Sticking those sizes in the Aussie rules gets you a GVWR of 1700 lb, which sounds a lot more than your trailer will weigh.

So I'd say you were bulletproof and well away from the stress levels where you would get fatigue.

Andrew

[rasp]

thanx guys.

i'm seeing the same price for 1/8' steel as for 1/4" aluminum for these sizes and shapes and 1/2 the weight.

[Jiminsav]

Rasp, 2 months ago, I went to the local metal distributor and they had 1 stick of 2x2 ¼ inch aluminum. 24 foot long..they wanted 200 dollars for it..I got a 2x3 1/8 , 24 foot long galvinized stick of steel for 90 bucks.

[rasp]

i guess i should have mentioned corrosion resistant steel. this is the place i was got my info from http://www.championtrailers.com/CORROSION_RESISTANT_METALS.htm#AL_BOX_TUBE

living in michigan one need the protection. i have seen lots of steel on the road that rusts in a year. ever the powder coated stuff never stays rust free for more than 2 years.
i have a metal fab place near me and i should get a good deal from there. on the metal and the fab.