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Weight of Teardrop Shell + flatbed trailer??

PostPosted: Thu Feb 18, 2010 12:51 pm
by okorokor
How much does a typical teardrop shell + flatbed trailer weigh? My design has a 6' x 8' floor, and will be mounted on a Harbor Freight, heavy duty 4' x 8' flatbed trailer. The teardrop shell can be removed from the flatbed trailer, as it has 4" x 4" and 2" x 4" floor joists. The weight of the teardrop is 750 lbs and the weight of the Harbor Freight Trailer is 250 lbs. So, the total weight to be pulled is 1000 lbs (the sum of the teardrop + the Harbor Freight flatbed trailer). Is this weight reasonable? Thanks very much, Okorokor :o

PostPosted: Thu Feb 18, 2010 1:08 pm
by synaps3
That's a bit high for a tear, but that's to be expected since you used 4x4's! :o

Most weigh in anywhere from 600-1000..

PostPosted: Thu Feb 18, 2010 1:16 pm
by Ageless
2x4, 4x4? Hey, you gonna hold a party for 12 in that thing? Way . . .way . . .way over-kill!

thanks for your feedback

PostPosted: Thu Feb 18, 2010 2:14 pm
by okorokor
Thanks for the two posts! Sounds like I am in the ballpark. Note that two 4x4 joists will extend 8 ft on each side, and 2 x 4 joists (6 ft long) will extend between the two 4x4s. Unfortunately the floor joists are necessary to be able to remove the teardrop shell from the flatbed trailer. I am using the two 8 ft. 4x4s, because I don't think 2 x 4s will be strong enough for an 8 ft. span, when the teardrop shell is propped up on cement blocks, at each corner. :)

PostPosted: Thu Feb 18, 2010 2:26 pm
by S. Heisley
This thread may help you:

http://tnttt.com/viewto ... ht=#606106

Look about halfway down the page that the above will take you to, for a summary of weights. Most use 1x2's; so, you'll need to add extra for your outsized pieces. For your 4x4's and 2x4's, perhaps you can stand on a bathroom scale, holding one of each, subtract your weight and double the resulting figure to equal 2 of each. Then add that to the average total weight given for your size in the above thread. That may give you a ballpark figure to work with; or, at least a warm idea.

Best Wishes!

PostPosted: Thu Feb 18, 2010 2:56 pm
by Ageless
Stop thinking about how houses are built! You are not going to have tons of structure being supported by the floor. The trick here is creating a laminated (read 'adhesives') that are stronger together than by themselves.

Take (3) 1X2 and create a screwd and glued I-beam. Then place it over sawhorses and walk on it. It's much stronger than the (3) individual 1X3 would be but weigh much less than your 4x4.

Re: thanks for your feedback

PostPosted: Thu Feb 18, 2010 3:03 pm
by aggie79
okorokor wrote:Thanks for the two posts! Sounds like I am in the ballpark. Note that two 4x4 joists will extend 8 ft on each side, and 2 x 4 joists (6 ft long) will extend between the two 4x4s. Unfortunately the floor joists are necessary to be able to remove the teardrop shell from the flatbed trailer. I am using the two 8 ft. 4x4s, because I don't think 2 x 4s will be strong enough for an 8 ft. span, when the teardrop shell is propped up on cement blocks, at each corner. :)


You may want to rethink about the lumber you plan to use.

In the picture below, my 10' long teardrop shell is supported at three points - once in the middle front by a hydraulic jack and twice at the rear corners on jack stands. My floor is 1x2s laid on edge with 1/4" plywood top and bottom.

Image

I didn't weigh the shell but would guess it was around 350-400# at that point (no hatch and no exterior plywood on the walls and roof.) BTW, I sat inside of the teardrop as is was shown and my 200# barely flexed the floor at all.

Tom

PostPosted: Thu Feb 18, 2010 3:45 pm
by Rock
My camper has no frame at all. The floor rests on only the spring brackets from the HF 1175# trailer.

Needless to say I can lift the whole camper right off the axle and it doesn't break in half. As shown this whole rig weighs 400 lb.

Image

Eric

Thanks for these great inputs - lighter is better!

PostPosted: Thu Feb 18, 2010 5:57 pm
by okorokor
Thank you'all very much for these great inputs! I am beginning to see, that lighter is better. :)

PostPosted: Thu Feb 18, 2010 7:12 pm
by mikeschn
Rock wrote:My camper has no frame at all. The floor rests on only the spring brackets from the HF 1175# trailer.

Needless to say I can lift the whole camper right off the axle and it doesn't break in half. As shown this whole rig weighs 400 lb.

Image

Eric


Eric,

That's pretty impressive.

My lightest build so far was 700#...

Image

but you need to paint your piece of the HF trailer black, and hang an fender above your wheel...

Can you tell me how you connected your tongue to the axle?

Mike...

PostPosted: Thu Feb 18, 2010 8:31 pm
by Rock
Mike,

That's your Ultralight design almost to a "T". The only deviations are plywood inside and out, fully insulated and covered in epoxy and fiberglass cloth.

For the tongue I took the 2 "A" frame components from the HF trailer and welded them into a single "box" beam. I think your PDF may have had them back to back creating a "H" section. Then I welded 1/4" tabs on top (again per your design) and bolted to the floor through framing in the sandwich floor.

I did put epoxy and fiberglass cloth on the bottom and top of the floor, otherwise I'm not sure I would have been comfortable doing this. It doesn't have a lot of miles but I'm highly confident it will hold together a long time.

I can only guess what the additional plywood, insulation, epoxy and fiberglass weighs, but I imagine that I could have come in at nearly 350 lb without them.

Yeah - I need to paint the trailer components and find some fenders. I can't find smooth aluminum fenders small enough for these wheels and I can't stomach diamond plate. I may try to fab my own to look just like Halfdome Danny's only smaller.

Eric

PostPosted: Thu Feb 18, 2010 8:45 pm
by mikeschn
Eric,

You did a good job on that. I am really impressed.

Mike...

Re: thanks for your feedback

PostPosted: Thu Feb 18, 2010 10:09 pm
by bve
okorokor wrote:I am using the two 8 ft. 4x4s, because I don't think 2 x 4s will be strong enough for an 8 ft. span, when the teardrop shell is propped up on cement blocks, at each corner. :)

Even if the floor isn't strong enough (which it should be) I wouldn't want to include all the 2x4 and 4x4 lumber in the TD - you could however use that lumber as a frame to sit on the cinder blocks and then set the tear on it - if it makes you more comfortable. Or build something like Amy used for a build table - it collapses - same idea just shorter legs - or no legs at all.
Image

BTW in this picture all that is under me is 1/8" ply and 3/4" insulation.
Image

Burke

How about this approach - Keep in mind it's a 6 x 8 teardrop

PostPosted: Thu Feb 18, 2010 10:58 pm
by okorokor
How about this?
You'all have given me some great ideas. The flatbed trailer is a 4 x 8, but the tear is a 6 x 8. This allows me to scizzor jack the tear's corners and pull the trailer out from under the tear, allowing me to use the trailer for other tasks.

I could use Tom's design, which is a 3/4" ply, hollowed out, and sandwiched between two 1/4 inch ply skins, I think. Insulation would be 3/4" rigid foam, I guess. I could try 1x 4 popular joists for the floor, the two 8 ft long, rim joists would be on each side of the tear, screwed and lamindated to the sides' 1/4", 3/4", 1/4" play sandwich providing pretty strong rim joists, I guess. Then, 1x4 6 ft. popular cross joists could extend across the floor, say spaced at 10 inch centers (maybe 12 inch).

I like Burke's idea of building a permanent mounting platform, for the tear to be parked on, but I'd like to have the extra floor insulation, anyway. So, I favor a ;) lighter floor joist system. I am hoping that poplar is quite strong, so that I could only go with 1 x 4s. Dick

PostPosted: Thu Feb 18, 2010 11:28 pm
by bve
You can probably get away with 24" centers on the floor joists, you won't be standing on it - when the 1/4 + 3/4 + 1/4 is all glued up it will be solid.

In Roly's 1/2 Nelson he used two hollow core doors which usually have nothing but perimeter framing.

http://www.gages-56.com/roly.html


Burke