Questions about design for ultralight bed-on-wheels (codename: Siesta)

[Betonhaus]

Do you mean .125" 2" x 2" tubing? That would be much better than your channel.

As far as cross members, you need one at the axle. You should have a second one a couple of feet from the front of your frame for the tongue to tie to.

You don't need cross members to support a 1/2" floor. You're not walking on it, you're distributing your weight while laying flat.

Here's a well-designed trailer frame. For your little trailer, you don't need the A-frame but you do need the box at the front to tie the tongue to.

Tony

yeah they are all 2x2x.125" tube except for the little guy in the back which is 1x1x.125", but maybe it needs to be 2" also.
true i can reduce the frame a little. considering the trailer is fairly short and the tongue uses a straight bar I can extend it to the axle beam, if I have only one 2x2x.125 bar that the torsion axles attack to I'm a little worried about twisting, but the bar is supported by the long bars right there so it should be fine?

And with bolting aluminum is it fine to use longer bolts that go through the whole thing or should I cut access holes so that short bolts can connect the two faces that actually touch each other? or would the plywood be not enough to give it enough twisting strength and I'll need to use brackets and such to reinforce the connections?

 

[NatersXJ6]

How are you framing the upper portion of the trailer? With a light duty lower frame, the wall frame can help provide a significant portion of the overall trailer rigidity, which should help tremendously with twisting.

 

[Betonhaus]

How are you framing the upper portion of the trailer? With a light duty lower frame, the wall frame can help provide a significant portion of the overall trailer rigidity, which should help tremendously with twisting.

1.5" ridged insulation foam and a fibreglass-alternate skin using truck liner reinforced with canvas fibers. I might glue 1/16" wall panels to the inside of the insulation for more reinforcement and to give the inside a stronger surface so random bumps doesn't dent it.
When applying the canvas and truck liner I intend to wrap the canvas around under then make a 1" stapled perimeter, which should better adhere the top shell to the frame.

At this point my cost and weight estimate is $2,000CAD/$1,600USD and 300lbs for the entire trailer excluding cargo.

 

[1000arms]

Hi I wanted to get a sanity check and part sourcing recommendations for a trailer I'm planning to build to tow behind my Fiesta. ...

+4 or 5 whatever the count is on nixing the MDF. It won't last. It won't hold screws. Use 1/2" exterior plywood.

I don't understand all of the channel you've got running lengthwise. If that's to support the floor, it's not needed.

I think you should reconsider using the channel for the chassis. Square or rectangular tubing is much stronger by weight and you can butt weld it without fancy fitting.

Tony

Are you aware that Teardropper has written a book "Building a Teardrop Trailer: Plans and Methods for Crafting an Heirloom Trailer"?

Eighteen months in the making... here's the book: Building a Teardrop Trailer: Plans and Methods for Crafting an Heirloom Camper

A long-term project that I'm quite pleased with. I have watched so many teardrop builders struggle (which is probably just part of the process). I hope this takes some of the angst out of creating one of these remarkable campers. 192 pages, 221 photos and 31 pencil biting chapters...

expeditionportal.com

 

[Ducstrom]

Anytime I towed a really light trailer, they bounce all over the place on bumps. The trailer tires would get airborne sometimes.
I don't know if you could dial that out of them with custom suspension. It would suck to build something awesome and have it get torn apart on the roads.

 

[NatersXJ6]

1.5" ridged insulation foam and a fibreglass-alternate skin using truck liner reinforced with canvas fibers. I might glue 1/16" wall panels to the inside of the insulation for more reinforcement and to give the inside a stronger surface so random bumps doesn't dent it.
When applying the canvas and truck liner I intend to wrap the canvas around under then make a 1" stapled perimeter, which should better adhere the top shell to the frame.

At this point my cost and weight estimate is $2,000CAD/$1,600USD and 300lbs for the entire trailer excluding cargo.

Aside from staples, what will bond the canvas to the foam And then bond that to the flat floor/frame? The foam alone can make a very rigid box if you can essentially weld the seams. I’ve never worked with it, so I don’t know what products can bond it well. If it was firm enough, and you had a good hot knife, you could probably finger joint it like a wood box. Will there be wiring? Where will that go? Getting that foam to bond strongly to your deck will be key to success in this endeavor.

 

[Betonhaus]

Anytime I towed a really light trailer, they bounce all over the place on bumps. The trailer tires would get airborne sometimes.
I don't know if you could dial that out of them with custom suspension. It would suck to build something awesome and have it get torn apart on the roads.

that's partially why i want the torsion axles. if you use a traditional axle what one wheel does effects the other, while split axles are completely independent. And I can get torsion axles dialed down to a 700lbs load capacity, which should reduce the bouncing as I'm not using axles rated for a much heavier load and are out of their nominal load range. After that it's hoping for the best.

Are you aware that Teardropper has written a book "Building a Teardrop Trailer: Plans and Methods for Crafting an Heirloom Trailer"?

Eighteen months in the making... here's the book: Building a Teardrop Trailer: Plans and Methods for Crafting an Heirloom Camper

A long-term project that I'm quite pleased with. I have watched so many teardrop builders struggle (which is probably just part of the process). I hope this takes some of the angst out of creating one of these remarkable campers. 192 pages, 221 photos and 31 pencil biting chapters...

expeditionportal.com

I did start this design before I knew about the book, I'll take a look later see if i can grab a copy.

Aside from staples, what will bond the canvas to the foam And then bond that to the flat floor/frame? The foam alone can make a very rigid box if you can essentially weld the seams. I’ve never worked with it, so I don’t know what products can bond it well. If it was firm enough, and you had a good hot knife, you could probably finger joint it like a wood box. Will there be wiring? Where will that go? Getting that foam to bond strongly to your deck will be key to success in this endeavor.

I was planning to use the proper glues for the foam, if there is a way to make them react and weld together that's even better. The canvas will be soaked with likely a urethan-based truck liner which should adhere to the foam fine. the wiring I was planning to stick in between the foam and the canvas/urethan shell and have them poke out where the lights go

 

[1000arms]

Are you aware that Teardropper has written a book "Building a Teardrop Trailer: Plans and Methods for Crafting an Heirloom Trailer"?

Eighteen months in the making... here's the book: Building a Teardrop Trailer: Plans and Methods for Crafting an Heirloom Camper

A long-term project that I'm quite pleased with. I have watched so many teardrop builders struggle (which is probably just part of the process). I hope this takes some of the angst out of creating one of these remarkable campers. 192 pages, 221 photos and 31 pencil biting chapters...

expeditionportal.com

... I did start this design before I knew about the book, I'll take a look later see if i can grab a copy. ...

I picked up a copy even though I don't have any plans to build a teardrop camper. I think there is a lot of good information in there to consider. For example, Tony's suggestion to have two doors if there will be two occupants makes a lot of sense for such a small camper.

Although I think it would be too big for your Fiesta, I'll mention the camping pod idea for anyone thinking of something very small, but with a greater hitch-weight-capable vehicle. No registration needed:

No Wheels Needed: Expandable Camping Pod Attaches To Your Hitch

It's like a teardrop trailer—with no wheels!

www.doityourselfrv.com

 

[Betonhaus]

I picked up a copy even though I don't have any plans to build a teardrop camper. I think there is a lot of good information in there to consider. For example, Tony's suggestion to have two doors if there will be two occupants makes a lot of sense for such a small camper.

Although I think it would be too big for your Fiesta, I'll mention the camping pod idea for anyone thinking of something very small, but with a greater hitch-weight-capable vehicle. No registration needed:

No Wheels Needed: Expandable Camping Pod Attaches To Your Hitch

It's like a teardrop trailer—with no wheels!

www.doityourselfrv.com

that is very cute actually. Won't work on my class II hitch with a 150lbs max tongue weight but it's still cool

 

[1000arms]

... Although I think it would be too big for your Fiesta, I'll mention the camping pod idea for anyone thinking of something very small, but with a greater hitch-weight-capable vehicle. No registration needed:

No Wheels Needed: Expandable Camping Pod Attaches To Your Hitch

It's like a teardrop trailer—with no wheels!

www.doityourselfrv.com

that is very cute actually. Won't work on my class II hitch with a 150lbs max tongue weight but it's still cool

Probably not, unless you make a HTT (Hitch Top Tent ) with legs that extend to the ground for full-support when in use.

Some houses/apartments/condos/etc have restrictions on parking trailers/campers/etc, but, the camping pod idea is just a glorified receiver rack, and might work well for anyone with the right hitch capacity.

 

[opp]

as this past 1950 fiberglass/foam will make the lightest pod. Plywood high cost can rot and heavy . we use this frame for trailers under 1200 . The lightest window is a willy window. Don't buy the lie that poly resin will eat foam. Just need the right home depot foam this trailer is 4.5 wide 4.5' height 7'11'' long and is 525 lbs with fat 13'' tires Glass/foam floor at this link a few light frames https://web.archive.org/web/20151114223707/http://www.angib.pwp.blueyonder.co.uk/teardrop/tear00.htm

 

[Betonhaus]

as this past 1950 fiberglass/foam will make the lightest pod. Plywood highView attachment 650961View attachment 650962View attachment 650963 cost can rot and heavy . we use this frame for trailers under 1200 . The lightest window is a willy window. Don't buy the lie that poly resin will eat foam. Just need the right home depot foam this trailer is 4.5 wide 4.5' height 7'11'' long and is 525 lbs with fat 13'' tires Glass/foam floor at this link a few light frames https://web.archive.org/web/20151114223707/http://www.angib.pwp.blueyonder.co.uk/teardrop/tear00.htm

I'm just using plywood for the floor, I haven't found a good substitute that isn't really expensive or impossible to find. I did get my wires crossed and somehow thought mdf would be suitable but I'm past that. I'm looking at Reinforced Polyurethane Foam but there's nothing nearby that sells it, but I think i can track it down eventually.
it's the same problem i'm having tracking down marine grade plywood, one of the downsides of living in a landlocked province. i might as well use normal plywood then seal it myself

 

[opp]

we do the floor with the foam has seam to work out great

 

[Betonhaus]

Door placement is critical. Put this book down for a moment and go lay on your bed. Now sit up and swing your legs off as if you’re getting up -–but sit there for a moment. Note that this is the same place that you sat on the edge of the bed before you laid down. Your pelvis will be about 30 - 33” from the headboard. This is where the doors need to be–- right next to where your hips rest when laying down and where you normally sit on your bed.

finally stumbled across this gem which makes perfect sense and... ********. I'll have to redesign and figure out how to work around the wheel locations

 

[Teardropper]

finally stumbled across this gem which makes perfect sense

Who in the world wrote that?

Tony