strongest way to build a frame

[matt987106]

hi again

after looking for a trailer to buy and covert in the UK, it looks like the best way is to build my own

the plan is for a 6ft 6 " X 4ft teardrop style, lightweight is the key here, must be as light as possible

loads of options, i was going to go with the A frame style, but as i want the cabin to be light, i was going to build it out of 12mm ply, i would worry that the sides would flop over the pointy bit of the A

so then came the square frame work, its not going to be that much heavier, we are only talking 1 more 4ft length

so then comes the tongue, after reading the guide, i still cannot work out thats the strongest /? ? /




then its the section to use, so whats better, L or box section ? ? ? ?

2 " big enough ? ? ? ?

if i used ali it would be rust proof, then again i could just hammerite ( or POR 15 ) some mild steel

any feedback advise

thanks
matt

[john]

Strongest to weakest.



A-frame

Composite

Single




The frame for my standy turned out perfectly serviceable, but I could have simplified it by not running the drop floor so far back and using a full length axle.

[wannabefree]

I would start with titanium.

[bobhenry]

This on is Planovets frame. What intriques me is the use of "c" channel as the "A" point. Running it back under the frame adds unbelievable strength. I put it in my album when I found it as a model for a custom frame if I am ever lucky enough to afford to have one built.

[len19070]

Here's how I did an "over the wheel build"







Happy Trails

Len

[matt987106]

thanks all

so box steel seems to be the choice

how big ? ? ?? 2" square ? ? ? or bigger ? ? ? ?

[doug hodder]

If you want an ultralight trailer and that sounds like what a 6'6" x 4 would be...here's a frame design by Andrew that would serve your needs. My builds are larger than what you are planning, but build in 2" tube, some as light as 16ga. Doug

http://www.angib.pwp.blueyonder.co.uk/t ... tear57.htm

[john]

I missed the part of your question regarding the size of your intended build.

Doug's right. I would go with Andrew's frame design for that size build.

BTW, my frame was done mostly in C channel, 1/4" along the sides and tongue, and 1/8" elsewhere. I did put the c-channel together to make a box to strengthen the area where the suspension mounted.

[matt987106]

If you want an ultralight trailer and that sounds like what a 6'6" x 4 would be...here's a frame design by Andrew that would serve your needs. My builds are larger than what you are planning, but build in 2" tube, some as light as 16ga. Doug

http://www.angib.pwp.blueyonder.co.uk/t ... tear57.htm

that was my initial plan

but i was concerned the 1/2" ply would flop down ( the solution to that is 2 X 2" wooden bearers , which i am not sure would weigh more than the sqaure metal frame )

[john]

If you are truly going light-weight, the box shape of the tear will give the strength you need.

Remember, the sides of the camper will carry the majority of the camper's weight to the axle, not the floor. The floor only has to support the occupant and complete the "rigid box" shape of the camper. A vertical piece of ply has a great deal of strength.

[angib]

Remember, the sides of the camper will carry the majority of the camper's weight to the axle, not the floor. The floor only has to support the occupant and complete the "rigid box" shape of the camper. A vertical piece of ply has a great deal of strength.

That is the absolute truth.

Andrew

[gullywompr]

If you want an ultralight trailer and that sounds like what a 6'6" x 4 would be...here's a frame design by Andrew that would serve your needs.

I was considering a clamshell design of about those dimensions (slightly longer). But because the design is split into a hinged lid and lower shell, it is not as torsionally rigid as a single box. Would this frame still be good, or would a more rigid frame be appropriate?

[doug hodder]

I'll go out on a limb and say yes. While I'm no engineer as Andrew is, I'd think that if it were hinged properly and when all buttoned up was tight, it should become a rigid box. I could be completely wrong however. Andrew might be your best resource for the correct answer. Doug

[Lgboro]

Could Andrews ultra light frame be built safely with aluminum? If so what size and kind of aluminum stock would be the best? I would love to build an aluminum frame ultra light in the 7 x 4 1/2 foot range to allow a just a little more interior room and take advantage of the lower weight and maintenance required by aluminum.

[angib]

Could Andrews ultra light frame be built safely with aluminum? If so what size and kind of aluminum stock would be the best?

Just roughly, for a lightweight trailer, either 1"x3"x1/8" or 1.5"x2.5"x1/8" rectangular aluminium tube would be good choices. I don't think 1"x2" is quite enough, though it's close.

Andrew