Axle placement and frame design question

[Forrest747]

I think u would be ok with 1/8th inch. Your doing two beams and your lateral support looks good. Just 1/4 inch gusset thicker front lateral be thicker to have more of a weld maybe use the same 3x2 for the front

[Forrest747]

ok in talking with a couple of teh guys over the weekend and looking at another drawing you did where you had teh center tongue go back further that would be the way to go. going over the calculations on my ipod (there is an app for this) you can get away with 1/8th inch siderailes and lateral crossmembers. i would do a 1/4 inch front and tongue. one person suggested notching the front crossmember and teh tongue. i would also then do a 1/4 inch thick gusset on the bottom. with the math your looking at a 5000 pound frame. good luck

[unicknn]

5000 lbs???? That seems a WAY WAY too heavy for a teardrop frame thats gonna be all plywood. Most of the info Ive found says these things way 1500 to 2000 lbs max. Why would I need a trailer that weighs 2 times the weight of most completed trailers?

[bobhenry]

I am gonna go out on a limb here and say Impact design has just entered the frame design topic. The 5000 pounds is a rating given to the force that would be needed to degrade (read rip apart of fatigue) the collective parts in some manner that will ultimatly lead to failure.

You may be surprised to know your 4000 pound rated hitch will not fail at 4001 pounds. Drawtite designs their hitches to just over a factor of two. So a 4000 pound hitch will start to fail at well over 4 ton. (8000#)

No your 4000 pound hitch doesn't weigh 4000 pounds this is the warning rating given with a hugh safety factor built in above that.

So I think in laymans terms your 5000 pound rated trailer is all about where you will start to stress the welds and materials in some manner that may lead to a potential failure. Much like the hitch above you now have a 1800 to 2000 pound tiny trailer on a frame that will withstand just over twice that rating in road impact and geometric forces without complaint flex or risk of failure.

[Forrest747]

+1 Bob Henry

Actual frame weight should be less than 300 pounds

[unicknn]

Ahh ok lol I was like WTF haha. Thanks for clearing that up.

[CarlLaFong]

Just thinking slightly outside of the box here. If you were to use a torsion type axle and rig it so your rams or actuators pivot the entire axle, you wouldn't need to build a notched frame. In the down position, the trailing arms would be straight up

[unicknn]

I had thought about something like that but the problem would be where to put the airbags. They need to be under the frame. If I could do it without a notch that would be awesome too. As it is Im having to use a 6" drop axle to lay the frame on the ground even with the notch.

I honestly dont really know anything about torsion axles though.

[Forrest747]

That is my issue as well is that I just do not know much about axles in general and torsion axles no clue