Way too heavy on frame; hints for light upper construction??

[working on it]

I've started (finally) building my dream weekender/minihopper variant. I've only been on this website for awhile (2 weeks), after wanting to build for 2 years. I had a 50"x60" (220 lb.) frame on 8" wheels with an overall length of 102" to start with. Now, 2 weeks later, I've reinforced all areas, boxed in a 50"x96" area with 1.5"x3" tube, and lengthened and strengthened the tongue with new 3"x3"x.188 square tube (to a new total length of 140"). Plus, I've installed new 5 on 4.5" hubs, and gone to 14" wheels. I haven't put the new fenders on yet, but I estimate that the new rolling weight at a frog's hair under 500 lbs. My goal at coming in at under 1000 lbs/100 lbs tongue weight seems very iffy right now. I was going to use a frp-1/2" ply-foam board-luan sandwich skin. Now I need input on some strong but lightweight walls that have been pioneered by others. Living in Texas. but camping in Northern states as well, dictates some insulation...but I've gotta go as light as structurally feasible. Nobody has listed the weights of the materials they used, nor the actual bare rolling weight of the frame (as far as I can tell). Can anyone help me here, I'm a bit undecided what to do now !!??

[asianflava]

Get out the cutting torch, plasma cutter, grinder. You don't need all that "reinforcement" this isn't a utility trailer. The box on top is where most of the rigidity comes from. The shelves in the galley and inside act as gussets for the box. All the frame does is provide a rigid place for the coupler and axle. Some have bolted their axle directly to the cabin, but I'm not a fan of this. Steel won't wallow out as quickly ad wood.

This is the frame for my 5X10, the entire thing is made from 2x2x1/8. I did change the tongue to 2x4 rectangular tubing, I wanted 2x3 but the place didn't have it.

[Oldragbaggers]

Wow, 500 pounds huh? I can't even imagine how you would get such a small trailer to weigh that much. My frame has plenty of reinforcement and my husband and I were able to lift it and turn it over. (We're not spring chickens anymore.) I don't know exactly what ours weighs, but probably less than 1/2 that.

I am sure the others are correct in saying you have way more metal there than you need. Go up to the Design Library and take a look at the frame for the Pico Light and you will get an idea of just how little metal one can get away with if the frame is well thought out.

Becky

[Lgboro]

I am using all cedar framing and have a cedar stripped the interior. I also have yet to use a metal fastener instead using biscuit joints and dowel pins to join all wood unions. Mine will be overbuilt as light as possible . I used a Tractor Supply platform (CarryOn) but with mods could have built a trailer the same or less weight and expense. I'm amazed at how strong the box has become as it nears completion. I could have used even less wood if I had known how strong a torsion box becomes.

[working on it]

Perhaps I didn't fully explain my vision. This build was always intended to be a dual purpose trailer; enclosed camping or enclosed utility. We have a full size (sorta) 24 ft tag a long for business purposes (where long term stay in a motel is either too expensive or unavailable) and two trucks to choose from for towing. And we have a heavy duty car hauler/utility trailer for real hauling, with the same tow vehicles available. However, gas prices being what they are, I wanted a lighter trailer able to be towed by either my HHR or the wife's Cobalt (i.e. around 1k lbs), and able to be used as a utility to haul my wife's business gear on short stay business trips -or- to replace her tent on her Cryptozoological expeditions (don't ask!!). I've always wanted a small TD type trailer, moreso than a full size, so I am trying to combine all in one. And I want to have the small trailer available when I finally get the time to visit the great outdoors again (haven't hunted or fished or camped out since 1978). So, though a bit heavy, this frame is as I wished, but now I'll have to cut corners the rest of the way to get close (good bye modular removable galley). Thanks for your responses so far, but short of deconstructing what I've got now, can anyone help me with the choice of materials going forward? I intend to start taking pictures of the frame and build as I go, but haven't had the opportunity or camera yet. p.s. the 500 lb weight is based on probable steel weights, tire and wheel shipping weights, a presumed 220 lb base frame, and little more. I lifted it on its' side yesterday, and guessed it weighs double what it did. However, at 61, I probably can't lift the guesstimated 500 lbs!! Only a scale will tell.

[wagondude]

Well, if your frame is what it is going to be, and your not willing to shed some steel, check out the foamie section for light weight builds. I think Eagles entire foamie weighs less than your frame.

http://tnttt.com/viewforum.php?f=55

Eagle's journal:
http://tnttt.com/viewtopic.php?t=43647

The thread that started it all (not for the weak)
http://tnttt.com/viewtopic.php?t=39373

Bill

[gww25]

I think that you can meet your goal of a total 1000# package with conventional stick and skin construction so long as you keep the surface areas small. You haven't posted a profile picture of the cabin yet so it's hard to say at this point.

[atahoekid]

Read the section on Foamies... A lot of us are building Foamies and some have come in about 650# total estimated weight. There are also those building a shell on top that can be removed so that the frame can be used for other purposes (utility). I think this is exactly what you're looking for....

COME, COME MY SON, COME TO THE FOAMIE SIDE!!!! (insert appropriate creepy, futuristic background music here) . It's worth reading the entire almost 180 page mega-post just to give you a good sense of the things we've tried, and discussed. Some ideas were dismissed, some worked well, others not. But it's all good and we love giving advice and we're nice people too!

[working on it]

I've since done more accurate assessments of the steel added, and of the other parts, per manufacturers websites...looks closer to 400 now. But the Foamie concept is not far from my sandwich skin idea> strong,light, and insulated. My plan was to go as light as possible , minimal bracing, yet able to withstand 70+ mph on the road (dragracer, you know). The basic shape is like my HHR Panel...a box with a 35 degree sloped angle forward, terminating in a 4x4 rear hatch. The slope will begin 21 inches above the frame, to match the height of the Cobalt's tail height, to stay in the wind shadow of either vehicle. After that, the rest is a rigid cubistic form. The sidewall may end up having an intermediate angle before the hatch, but that will be determined after a full size cardboard mockup comparison. I know the frame will withstand the road, but the challenge is to keep the cabin from flying off at speed. I wish I could afford Aluminum honeycomb on plywood, but a foam sandwich (if strong enough) would satisfy my appetite, so to speak.

[working on it]

Rolling trailer now has fenders and removeable,swivelling jack on tongue. I'm going to attach a plywood floor tomorrow. Either birch or oak 1/2" thick. Attachment by 12 (3/8") carriage bolts to original frame (50"x60"), and either Loctite PL or Liquid Nails w/ self-tapping screws to frame extensions. Underside to be sealed with auto undercoating spray (I'm a long time shadetree mechanic, this stuff is one item I know and trust). The top surface and sides of the floor will be polyurethaned. As for the future sidewalls and rooftop, I've got feelers out thru some contacts for filon/ply/filon panels, and maybe a EPDM roof. Until I finalize these on items, the roller w/floor will be stored in a shop out of the weather. p.s....While welding on the fenders, I lifted the rear of the trailer off the ground, just balancing on the jack momentarily. Now I'm thinking it weighs under 400lbs. Or maybe I'm just pysched up over building it! Took some pics on my phone's camera, but haven't figured how to download them.

[bobhenry]

If you want to take some of the ???? out of the weight question drag out the bathroom scales. If you don't own any ask the neighbors. Block under the non scale tire so the trailer is dead level with the other wheel on the scale already. Multiply by 2 and now measure the tongue weight and add all together. You won't be dead accurate but you will be a hell of a lot closer than you are now. If you bench pressed all the weight but what was tipped to the tongue it is no where near as heavy as you think.

[working on it]

Finally weighed it today on truck/freight scales.. With lights and finished floor = exactly 400 lbs. Battery and box and spare tire w/mount this weekend should add 80lbs. Already have a 75lb. generator ready to mount as well. 1000 lb goal-555 lbs=445 lbs left for actual structure. Gonna be tight...no cement blocks or boiler plate.