How strong does the frame need to be?

[MoparCzy]

I apologize if there is already an answer to this question on the forum, maybe I am just not searching with the correct terms. If I am building a 5' x 10' teardrop, just how strong does the frame need to be? 2" square tubing all around the perimeter of what thickeness? Plus a 2" square tube to attach the split torsions axles to? Floor will most likely be 1/2" ply with insulation and 1/8" ply on the bottom. If I build the floor with dimesional 2x2 lumber and put that on top of the steel frame, do I need to add any more cross braces or will just the one under the axle be enough? The reason I am insulating the bottom is that we would like to camp longer into the year and want the trailer to not lose heat from the bottom.

[madjack]

...the short answer is..."not very"...a properly constructed TD forms a torsion box which is stronger than most reasonable frame can be...take a look here http://www.angib.pwp.blueyonder.co.uk/t ... tear57.htm a 2x1/8 tube perimeter frame is fine...care needs to be taken with the tongue...an "A" or "Y" frame tongue is MUCH better than a single tube tongue...............
madjack

[MoparCzy]

Okay, so in that case, if I do want a full frame under the perimeter of the trailer, and using the assumption I made in my first post of a 2"x2" lumber floor with 1/2" ply on top and 1/8" below to sandwich the insulation, then I could use thin wall 2" square tubing and know it is strong enough to handle the load of the completed trailer and possibly need to use much thicker 2" square tubing for the tongue? I had planned on running the cross members every 24" inside the floor to support us.

Thanks for the information. I need it to explain to my friend who welds that we don't have to build the frame super strong. As others have posted, he is used to building utility trailers for hauling stuff up to and including cars.

[madjack]

...explaining to the "pro" trailer builder what you are wanting and getting him to doit is always a problem...my present frame is 1x2x3/16 "C" channel with 2x1/8 angle crossmembers...the tongue is a "Y" design with a 2x1/4 center tube and the "C" for the side braces and is MORE than sufficient for a teardrop...with the composite floors, you could probably do away with the crossmembers except for the the first one back to connect the center tube of the tongue to...which could be run all the way back to the axle connecting crossmember, eliminating that one as well...keep in mind, with a composite floor and the torsion box construction of the tear, all the framing you need for the trailer is to connect the coupler to the axle...
madjack

[aggie79]

+1 on what MJ said.

I used 2x2x1/8 tubing for the trailer perimeter and 2x2x3/16 for the a-frame tongue. I have an insulated floor (1/4" ply, 3/4" framing, 1/4" ply). The only two cross members I have are just behind the a-frame and one at the rear as an inboard mounting point for a receiver and two stabilizers. My trailer is 56" wide. The composite floor has been loaded to 400 plus pounds and doesn't flex.

I do have a torsion axle that also serves a crossmember.

Tom

[doug hodder]

I've built using 16Ga. ~.060 thick 2x2 tubing and .125" thick 2x3 tongue....you can really save a lot of weight on the frame. Doug

[Arne]

i modified a h/f frame to a perimeter frame.... works very well and got rid of a bunch of weight..

go to link below and look at first pic.... in a frame, height is much more important than width.

[MoparCzy]

I saw on your construction pages that you planned on weighing the frame when you finished it, what did you end up with? Also what did your finished trailer end up weighing? Thanks.

i modified a h/f frame to a perimeter frame.... works very well and go rid of a bunch of weight..

go to link below and look at first pic.... in a frame, height is much more important than width.

[bve]

When I first started looking to build a TD I found a used pop-up frame for free and intended to use it after narrowing it, however although I got the dimensions I was after I still felt it was way too heavy http://tnttt.com/album_ ... c_id=38355 so I turned it into a utility trailer http://tnttt.com/album_ ... c_id=58206

I had a frame from my parents' first camper (basically a tent on a box) which I was using as a utility trailer, I have since modified it and feel it is much better suited. It is much lighter - for the record the modifications are just tacked together in these photos as I am still in the planning stages. http://tnttt.com/album_ ... c_id=58207 http://tnttt.com/album_ ... c_id=58209

The smaller frame is essentially the same as Arne's modified HF frame, a wishbone with a few cross members to attach the camper shell.

[Russ in California]

.....care needs to be taken with the tongue...an "A" or "Y" frame tongue is MUCH better than a single tube tongue...............
madjack

Not always. (read: see Larry Sorensen)
I plan to use a 3x3 single tube tongue, as Larry did, which will, among other things, allow for much tighter turns. Even 90 degrees.
"Depending on your usage", this could be more advantageous than an 'A' or 'Y' frame tongue and properly gussetted, just as or stronger than the A or Y frame though they seem to be more 'the' standard design.
JMTC (read: just ask Grant Whipp),

[Arne]

The frame alone weighed in at just under 100#... not including spring/axle. I weighed the nuts/bolts/washers I got rid of by welding... 15#...

t/d was built with 1.5" studding/insul all around, sandwich floor, and fully loaded, ready to go, with spare and torsion axle, full galley, mattress, etc., came in at 1,100#...

-----------

regarding turns, I've never seen the need for a 90 degree turn on my t/d, but have on my utility trailer.

With the t/d, I can turn as tight as possible going forward, hit about 45 degrees, and still have 8" of clearance with a 24" tongue... with the t/d, and backing up, if I get to 45 degrees, I've already lost it.... and have to pull out and start over.....

[madjack]

...you are correct...if engineered properly, a single tube tongue can work just fine but IIRC, Larry had his original tongue break and had to re-engineer it...I still like a modified "Y" the best, a long center tube braced a 1/3 to 1/2 way from the body will work pretty well in those tight areas and help eliminate some of the "harmonic" problems that have been reported using just a single tongue...it also gives a nice spot to mount tongue boxes and other accessories............
madjack

[Arne]

The Y gives a more rigid mount because it is triangulated. The straight tongue has to be made a lot heavier because it the side walls have to be beefy enough to handle the side to side wiggles that can not occur with the Y...

[Lou Park]

I made in my first post of a 2"x2" lumber floor with 1/2" ply on top and 1/8" below to sandwich the insulation, then I could use thin wall 2" square tubing and know it is strong enough to handle the load of the completed trailer and possibly need to use much thicker 2" square tubing for the tongue? I had planned on running the cross members every 24" inside the floor to support us.

Just my opinion but, If you're going to space supports at 24" centers, I would go to 5/8" or 3/4" ply floor. If you're using thin wall 2x2 tubing, definitely consider the "Y" set up for the tongue. If not, 2 things might happen. You create a leverage from the single tongue that will bend the first support up and the second support that it's attached to down. I would also change the tongue to a 2x3, it's much easier to find a hookup that will fit the 2" tongue, but still have the strength of the 3".
Lou

[Billy Onions]

I agree with Lou.

I would me more tempted to go for a thicker wall tubing.

That said, spacer tubes at 24" in my opinion is way way overkill. An 'A' shaped drawbar/tongue under the 10 x 5 frame from 2 x 2 x 12 guage and I would put a couple of 1/8" thick 2 x 1 'C' channel to brace and to fasten the floor to. I would be happy with that on my trailer.

Your build will be heavier when finished than you estimate at the start of your build, when looking back at the end where you could have saved weight it's going to be a bummer to think you need to start chopping the chassis around.

Here is a link to the Kit frame from another thread on here recently, not a lot to it at all and something to think about maybe.

http://tnttt.com/viewto ... hlight=kit