Can this be done? Trailer building question(s)

[chumly2071]

This book and it's sequels give some good info on trailers. There are no specific designs contained in it, but a lot of examples of what to do, and what not to do. Might be of some use to you. I have vols. 1 and 2. There was rumored to be a three, but I never saw it.

 

[easygo]

Well I decided to go ahead and buy the steel because it was only $45 for eight pieces ranging in length from 17'-19'.
Blagadan: Since people here mostly suggest I should go with the heavier material I decided that I will do farther research weather I could get sufficient strength out of the 1/8" box stuff. I will see if I can contact a local engineer and ask their opinion on how to get the most out of the given material. I know what you mean about having to load the trailer tongue heavy. That is the way of life for me and I thought they are all supposed to be loaded like that.

chumly2071:
It is on my list to visit a book store or library and check out that book before I decide to buy it. I read some bad reviews on it recently.

Thanks for all your advice
Easygo

 

[bjcsc]

Most single axle boat trailers are made from .125 wall tubing...

 

[RobJ]

I think you'd be fine with the 1/8". Carrying your tractor with an implement, FEL and all might be a bit much for a long haul. Short haul no problem. Your axle mounts are going to be 3+ feet apart to spread out the load. Plus if you use 2x6 or 2x8 to deck it you'll get those to spread out the load. Also what many forget is if you weld on the side rail you've now got a quasia truss type support on both sides. $45 is dirt cheep for that metal.

Here is a 5x12 I built about 10 years ago.

Good Luck,
Rob

 

[easygo]

RobJ, Thanks for the good word. That trailer looks good. I do plan on using 2x6 or 2x8 decking and build a 12" or so high side rail as you mentioned. I plan to copy the pattern of that from an engineer designed truss from a bridge or a trailer. Could you tell me how many cross braces you used under the deck and what was the load capacity you ended up with? I understand why people shy away from giving advice on something that may be a questionable project, but trust me I don't intend to do a half apple job.

 

[bobodu]

Just put your cross braces ("joists" if you will) on 20-24" centers. I put them 30"OC on my dump truck,overlaid with 3/4" subfloor plywood and 1/8" steel sheet...nothing has broken though yet. It ain't like you're gonna load a 2 ton steel wheeled tractor on this thing.


I did end up rebuilding the hoist on this truck though...not because my design was bad,the neighbor wasn't paying attention and pushed the rams off the hinge.









This pukey little trailer has been hauling and dumping one ton loads for five years now.

 

[rdln]

You will be fine with that material, build a ladder type side rail over the spring mounts as mentioned, 2 foot o.c. crossmembers. Most spring hanger brackets are made for 2" wide frames, I would find some .25" plate, cut out right triangles about 6 inches high, drill for bolts assemble to springs, clamp to frame and adjust for squareness and tack them on, disassemble and weld them up.

1/4" to 1/8" thickness welding aint no problem.

Now for the tongue, if you dont want a 50degree job you should pick up 2x2 .25 wall

 

[Renze]

Here is the thread i made, of converting a 2 ton 2 axle trailer, to a 6 ton tandem for agricultural use:

http://www.tractorbynet.com/forums/build-yourself/118921-home-made-bale-trailer.html

I fabriced a frame out of 80x50x4mm tubes, which is 3 1/8 x 2 inch tubes, i dont know what the wall thickness of 4mm is in fractures of an inch.

This is lightweight material, but because of the main frame rails being spaced wide, with lots of braces, it is a light but very strong frame. I calculated it to a safety margin of 2, which is the same as i use when calculating and designing trailer frames at work.

What you are talking about, roughly converts to 76x38x3mm, which is very useful to fabricate a frame rail from.
For the 3500 kg mid axle deck-over trailers (7000 pound), we regularly use 60x60x3mm tubes spaced about a foot apart and gusseted with smaller 1x2" tubes. And everybody knows Doornwaard trailers arent cheap, but built to last

If you want to build it with the deck inbetween the wheels, and not have enough height to space the frame rails enough, i'd go with heavier walled tubes, or weld a piece of flatbar on top and below it, to add material where it matters most.

How are regulations in your state, regarding trailer brakes, rear underride protection and towbar test certificates ?
We normally use 2x4" square tubes as V towbar, with a wall thickness of 4mm (1 inch is 25.4 mm)



I am an engineer at a trailer builder in Holland, building from 3 to 30 ton, so i could give you some advice... now only if you could talk metric....

 

[RobJ]

RobJ, Thanks for the good word. That trailer looks good. I do plan on using 2x6 or 2x8 decking and build a 12" or so high side rail as you mentioned. I plan to copy the pattern of that from an engineer designed truss from a bridge or a trailer. Could you tell me how many cross braces you used under the deck and what was the load capacity you ended up with? I understand why people shy away from giving advice on something that may be a questionable project, but trust me I don't intend to do a half apple job.

Here is a few more pics for you. I don't know what it's exactly "rated" for. I build it to haul what I need. Specs were the same as bought trailers. The place where I bought the parts (Husky) said to take my time and take all the measurements I wanted from their trailers on the lot. Not a problem. Key is the axle is 60/40 split. 40% of the lenght behind the axle. I did mess up the rail height. Can recall why I designed it that way but as you can see I had to go back and add a middle strap. A standard Igloo cooler would slip under it!! I also built the ramp and all. If you have extra steel, just toss it in the supports, instead of 24"oc, go 16"oc, etc. I think I ended up with more around the axles, the front hitch V will add more support up there.

When I got the tractor I sold that one and build one a little bigger. 7'.5'x14' sled style. In hindsight 16' would have been nice (and I had the steel), but in reality the RC hangs out the back if needed.

The pics..

 

[easygo]

Great Ideas and photos thank you guys.

rdln: Thanks for the spring hanger idea. That was one of the things on the list of unsolved problems. I haven't quiet decided on weather I will make it a tilt trailer or a heavy tailgate, but I'm leaning towards making the "V" towbar and tailgate .

Renze: Thank you for the offer on helping out. I will draw up a blue print and will send you a file if that is all right. I will convert the measurements into metric I like working with that anyway.

RobJ: Thanks for the pictures. I'm hoping to build something similar to the red trailer you have/had. Thanks for the detail shots too. They are very useful.

I want to let you guys know that I don't plan on starting the project until the fall. may be in October when the weather turns a bit cooler. Until then I will enjoy the short summer here. But it looks like when I'm ready to make the first cuts and weld I should be ready for most of the challenges.

Thanks again
Easygo