"Standy" frame questions

[MatthewWorks]

Xanthoman -

Singcore.com is the site.

Thanks - damn those panels look amazing. The ones I saw one their site were essentially insulated torsion boxes. Looks like they sell through Lowes nationally, will have to look into it. Trailer will certainly be insulated, might be less $$ to self make the SIP panels, I should double check that.
I wish I didn't want it covered in aluminum as much as I do. It'd be easier. I'm a metalsmith, I can't help it... Anyone ever start with just sealing the wood, and adding metal later?

CurryR-

Give good thought to your tow vehicle.

Yep, both tow vehicles are appropriate, thanks. Trailer will be switched back and forth between them. I think I mentioned in the original post that not everything will fit in each vehicle. This is my best-use case scenario, or else I'd just build standard camper/teardrop. As is, even loaded with my cargo, it'll weigh less than a heck of a lot of campers out there.
edit: just to note, I'm definitely putting electric brakes on the trailer. Legally not necessary, but driving in the mountains can be enough stress on a loaded cargo van's brakes. Just nice for driving overall.


I keep wanting to call the yet-unbuilt camper the "The Can-Do", since it's a Canned Ham that does more...
(but that's even cheesier than my usual self... it could happen)

[MatthewWorks]

Huh. Just came across a local Craigslist add for a 22' tri-hull boat trailer. Those boats usually weigh around 3K lbs... might be the needed affordable start. Couldn't buy the steel for the price, if the width is right (and it looks close...)

[M C Toyer]

Some good potential there. I've used several boat trailers in builds and they are usually cheaper than a comparable sized utility trailer.

The small wheels look to be 4 lug but the hubs could be changed to 5 lug to give you a wider choice of wheels and tires if you wanted to go larger.

With boat trailers that have been submerged be sure to check / clean / repack the axle bearings. If the frame members are boxed check carefully for heavy rust where water might have been trapped.

Lot easier to shorten the tongue than extend one but as it is now would allow you extra length on the cabin plus some room for a tongue box, etc. The axles are normally set farther back on boat trailers so you might have to reposition to maintain the proper tongue weight.

[MatthewWorks]

Some good potential there. I've used several boat trailers in builds and they are usually cheaper than a comparable sized utility trailer.

The small wheels look to be 4 lug but the hubs could be changed to 5 lug to give you a wider choice of wheels and tires if you wanted to go larger.

With boat trailers that have been submerged be sure to check / clean / repack the axle bearings. If the frame members are boxed check carefully for heavy rust where water might have been trapped.

Lot easier to shorten the tongue than extend one but as it is now would allow you extra length on the cabin plus some room for a tongue box, etc. The axles are normally set farther back on boat trailers so you might have to reposition to maintain the proper tongue weight.

Great tips, thanks. I was looking at the Aluminati build thread: viewtopic.php?f=50&t=60405 and this trailer came up on CL not long after. Looks to be a lot less frame rebuilding this way, if it works.

If the axle is decent, I'll use it (moved) for a bit, replace with a torsion axle later as the $$ allows. The more I keep the initial budget down, the more likely it is that I can get it done this winter.

Also, I won't post about every trailer I see... just got excited when I realized this is still possible. Boat trailers are around quite a bit.

[MatthewWorks]

No luck on finding a used trailer yet, might need to build it, but still looking. I suspect that if I'm building the trailer = not getting it done enough in time + more initial expense.

Some updates on the design:
5' trailer, 6' wide body.


Space for small suitcases left of door, small cabinet by the head of the bed on passenger side. (all adding support for structure, as well. 2' x 4' bathroom (shower later) front driver's side, room for fresh and grey water tanks. Other cabinet at front will be kitchen area.

The windows as shown would be great... but it might not happen as such. They're vintage windows, which would add problems along with style. We'll see.

Plenty to go yet: Fenders aren't right yet in drawing, not showing hatches at rear. Still lots to plan.
Due to support needed, and needing to lessen the amount of experimentation, I think I'm going with the plywood skeleton with interior and exterior faces of plywood method. Looking at 1/4" | 1/2" |1/8" (exterior to interior) method, as per Grant Whipp. Still hoping to cover it in aluminum if money and time allows.

Y'all are great. Thanks for all the info out there. Putting this out there, in case it helps anyone later. Hope to edit/comment if what I do causes disaster.

[swoody126]

Huh. Just came across a local Craigslist add for a 22' tri-hull boat trailer. Those boats usually weigh around 3K lbs... might be the needed affordable start. Couldn't buy the steel for the price, if the width is right (and it looks close...)

THIS^^^

a bit of patience should produce several options that will make your build less expensive, though may require a bit of labour to make the results warm n fuzzy

i just picked up a galvanized boat trailer in a size range similar to your needs w/ 3500# capacity for $280 and 60 miles each way to get it

came w/ LED lighting system that us fully functional, full fenders(not the dinky skull cap style), 2" hitch coupler & 15" tires that are less than 2 years old & have plenty life left on them

I WILL go completely thru the syuspension system addressing every moving part and servicing/replacing as needed

your post is telling me you need a 5' x 10' frame(rectanguar portion, before the frame bends to form the tongue) w/ a 3500# capacity which is frequently available in my market

you may have to shorten the tongue which is a no-brainer

they're out there

GOOD LUCK W/ YOUR QUEST/BUILD

sw

[MatthewWorks]

a bit of patience should produce several options that will make your build less expensive, though may require a bit of labour to make the results warm n fuzzy

i just picked up a galvanized boat trailer in a size range similar to your needs w/ 3500# capacity for $280 and 60 miles each way to get it

came w/ LED lighting system that us fully functional, full fenders(not the dinky skull cap style), 2" hitch coupler & 15" tires that are less than 2 years old & have plenty life left on them

I WILL go completely thru the syuspension system addressing every moving part and servicing/replacing as needed

your post is telling me you need a 5' x 10' frame(rectanguar portion, before the frame bends to form the tongue) w/ a 3500# capacity which is frequently available in my market

you may have to shorten the tongue which is a no-brainer

they're out there

GOOD LUCK W/ YOUR QUEST/BUILD

sw

Thanks, SWoody. Hoping for the patience, and the luck. Sounds like you nailed it. I think you're exactly right about what I need, and then shortening it to a 5 x 9 trailer.

(the pic above with the cute kid was only a 4' wide trailer.)

Have to mention, after sitting here, figuring out a few details, I realized instead of re-inventing the wheel I could give Steve Frederick some money and buy his write-ups. Been a nice read. While I don't think I'll be following his shop-manual step by step, it's given me some seriously good info. Saved me some time, and I can devote my three neurons to some other aspects.

cheers, all. Wish the Craiglist gods to be in my favor.

[rowerwet]

old camper trailers could give you a useable frame for a little demolition work.

[MatthewWorks]

old camper trailers could give you a useable frame for a little demolition work.

I've seen a a good number of pop-tops, but been unsure of weight rating. (I know I'm not building THAT big of a trailer, so I may be worrying needlessly.)

We live in the city, with a backyard that's about 14' x 25'. So I have to be a bit careful about demo projects, but I'm watching.

EDIT: Also, most of the pop-ups have the small (10"?) tires... and I'm hoping for a frame with an axle that's good for a season. A normal camper frame would be better in that case. But I do wonder if I'm steering myself wrong about not using the popups.

Sent from my SM-N900V using Tapatalk

[MatthewWorks]

If I do end up building the frame, any thoughts on this design?

notes: All frame members are 2 x 2 x 1/8" steel tube, with the exception of the tongue which is 2 x 2 x 1/4" steel tube. Tongue assembly is sitting under the rest of the frame. Crossmemembers might not really be in quite the right spots. Need to add in spots to bolt down deck, and corner braces for leveling jacks.

Dimension on the overhang is 9"... could those be skipped and the deck built to overhang that much? (as I re-read this post, I wonder about making the extensions about 4", and using them for the bolt-down spots...)





Much thanks to DMcCam who put so much info out there, I found your info a great place to start.

EDIT: Search more extensively on the subject of overhangs, I see that I'd be okay. Gives me some ideas.

[MatthewWorks]

Alright, y'all. Any problems with this frame plan? All steel shown as 2x2", 1/8" walls. Remember, it's for a trailer that needs to carry around 2500 lbs. I'm hoping to order steel next week. Please fire away with any problems.





All steel is 1/8" thickness, 2" x 2". The sides are 1 x 2 x 1/8".

Simplified a fair bit from the last version,removed center support/extended tongue...

[swoody126]

hey Mathew, if i were doing it i would consider the dimensions of sheet plywood when placing my cross members. using spacing that allows for the natural/straight/parallel sheet edges to fall on the center of a cross member reduces your seams and therefore reduces the number of screws and work instaling them. it also eliminates some of the ripping of the large sheets, which can be a bit unwieldy for a solo builder(like me). since my computer doesn't have the best resolution i could be in err butt the way you have your cross members spaced makes me think you will have to rip 4 full sheets of plywood to build your floor when by considering re-positioning your cross members you could use 2-full widths and just a 1' strip to floor the deck whch would reduce the number of seams to deal with.

all just the musings of a LAZY OLD MAN

sw

[MatthewWorks]

Hey all, a bit of rework on on frame design. Frankly, I'm (currently) more intimidated by making sure that I design it well, than I am about welding it well. I'd really love some serious critique.

Now that I've found the spreadsheet that angib created for tongue design http://tnttt.com/Design_Library/tear84.htm, I've looked at what that calls for. Holy toledo... because of the weight I expect to carry (2500lbs, as a combo cargo/camper) it calls for some serious steel. Copied from my spreadsheet:

TONGUE STRENGTH, A-FRAME Input your data in yellow boxes, read result(s) in blue box(es)


User Inputs
Trailer use/type Braked road

Trailer loaded weight, pounds 2500

Tongue length, L, inches 52

Tongue eccentricity, e, inches 2

Steel type Mild steel
Yield stress, psi (lb/in2) * not required *
Ultimate stress, psi (lb/in2) * not required *

Tongue fabrication method Welded



Results
Minimum section modulus, each side, Z, in3 1.059

Now look in table below for section with suitable Z value - % req'd above 100%
Bigger dimensions (width, depth) are better for weight and stiffness than thicker steel



Section Properties Z, in3 % of req'd weight, lb/ft
Angle
2" x 2" x 1/8" 0.129 12% 1.65
2" x 2" x 3/16" 0.188 18% 2.44
2" x 2" x 1/4" 0.244 23% 3.19
2.5" x 2.5" x 3/16" 0.280 26% 3.07
2.5" x 2.5" x 1/4" 0.364 34% 4.10
3" x 3" x 3/16" 0.414 39% 3.71
3" x 3" x 1/4" 0.569 54% 4.90

Channel Channel is with web vertical, so flanges at top and bottom
3" x 4.1 lb/ft (0.17" web) 1.10 104% 4.10
3" x 5 lb/ft (0.258" web) 1.23 116% 5.00
3" x 6 lb/ft (0.356" web) 1.38 130% 6.00
4" x 5.4 lb/ft (0.184" web) 1.92 181% 5.40
4" x 7.25 lb/ft (0.321" web) 2.29 216% 7.25
5" x 6.7 lb/ft (0.19" web) 2.99 282% 6.70
5" x 9 lb/ft (0.325" web) 3.56 336% 9.00

Square Tube
2" x 2" x 1/8" (11ga) 0.486 46% 3.05
2" x 2" x 3/16" 0.641 61% 4.32
2" x 2" x 1/4" 0.964 91% 5.41
2.5" x 2.5" x 1/8" (11ga) 0.799 75% 3.90
2.5" x 2.5" x 3/16" 1.08 102% 5.59
2.5" x 2.5" x 1/4" 1.30 123% 7.11
3" x 3" x 1/8" (11ga) 1.19 112% 4.75
3" x 3" x 3/16" 1.64 155% 6.87
3" x 3" x 1/4" 2.01 190% 8.81
4" x 4" x 1/8" (11ga) 2.20 208% 6.46
4" x 4" x 3/16" 3.10 293% 9.42
4" x 4" x 1/4" 3.90 368% 12.21

Rectangular tube
2" x 1" x 1/8" (11ga) 0.280 26% 2.20
2" x 1" x 3/16" 0.350 33% 3.04
2.5" x 1.5" x 1/8" (11ga) 0.535 51% 3.05
2.5" x 1.5" x 3/16" 0.705 67% 4.32
3" x 1" x 1/8" (11ga) 0.545 51% 3.05
3" x 1" x 3/16" 0.713 67% 4.32
3" x 2" x 1/8" (11ga) 0.867 82% 3.90
3" x 2" x 3/16" 1.18 111% 5.59
3" x 2" x 1/4" 1.42 134% 7.11
4" x 2" x 1/8" (11ga) 1.32 125% 4.75
4" x 2" x 3/16" 1.83 173% 6.87
4" x 2" x 1/4" 2.25 213% 8.81
4" x 3" x 1/8" (11ga) 1.76 166% 5.61
4" x 3" x 3/16" 2.47 233% 8.15
4" x 3" x 1/4" 3.07 290% 10.51

Round tube
2.5" x 1/8" 0.495 47% 3.17
2.5" x 3/16" 0.692 65% 4.65
2.5" x 1/4" 0.862 81% 6.01
3" x 1/8" 0.730 69% 3.69
3" x 3/16" 1.03 97% 5.65
3" x 1/4" 1.30 123% 7.35
4" x 1/8" 1.34 127% 5.18
4" x 3/16" 1.92 181% 7.66
4" x 1/4" 2.45 231% 10.02

So: For the tongue, I'm thinking 2x3" steel tube, 3/16" walls. (Really? So heavy????)
For all else, 2x2 1/8" walls. Drawing doesn't show it yet, but lots of gussets at the corners for additional strength and attachment points.
But again - is this serious overbuild? I don't see any cargo trailers at the 2990 rating being built this well. Maybe that's okay.




(image seems really small, here's a link to a larger version... https://goo.gl/photos/nNZnW9uP9hBNa5MA6 )


The design reworked is as above. A few notes:
* I might reduce the overall width back to 6'.
* I'm thinking about torsion half axles... I like the idea that if needed I could change the spindle height to get into my garage, plus reduce the weight.
* The area cut in for the wheels an axle is a bit over large... because I'm terrified I'll weld the entire thing together, build the shell, and then realize I was completely off on the axle placement. I think it's worth having a bit of extra fudge space.

I'd seriously love some input, please tear the problems apart! The plan is to order steel in about two weeks and get to welding...
cheers!

[MatthewWorks]

Any thoughts on the post above, anyone? I've dug around quite a bit, not sure how much more homework I can do before asking. Perhaps, if anything, I wonder if I should increase the wall thickness on the non-tongue portion up to 3/16 as well. I'd love not to, but if the general thought is that I should, I'm game.


Also, I'm lucky. I've been babbling about this at home for a good month now. My better half is game on the entire project, and doesn't want me to take shortcuts if I don't have to. It'll be a question on funding through the winter, but I still would love to get this started, and see how far I can get it rolling, even if I cant get it "campable" by spring.

cheers, and thanks for any input.

[MadMango]

I think 2x2x.125" tubing is really heavy and overbuilt for your trailer. I suspect that you could go with 2x2x.083" tubing and be just fine, .060" might be too thin. I would say .125" for the tongue extension.

.060" yield is ~30,000psi, and weighs about 1.6 lb per foot.
.083" yield is ~32,000psi, and weighs about 2.1 lb per foot.
.125" yield is ~46,000psi, and weighs about 3.1 lb per foot.

Your trailer isn't going to weigh over 1,800lb, and you're not going offroad rock climbing with it, right? I'm a noob here when it comes to teardrops, but have worked with metal most of my working career.