Trailer frame sizing

[milkie62]

Does anybody know of a site where I can get frame sizing of metal ? I was thinking of making a 5x8 hyd dump with a 16" wheel for hauling firewood.

 

[Renze]

its not that easy. forces depend on weight size and position of the tipping cylinder, towbar and axle. I dont think you'll get the straight answer you're looking for.

 

[rdbrumfield]

Building a hyd dump on a trailer with a single axle is a risky thing to do. The hinge has to be as near to the axle as possible. If you hinge it at the rear it will put a lot of lift on the rear of your pulling rig, possibly picking it off the ground.

The tongue and main frame of the trailer has to be overbuilt a bit to withstand the lifting and changing center of gravity as the load is picked. I would tend to make it a bit tongue heavy. The farther back you can put the axle within reason, the better it will make it for dumping, and will be easier for backing too.

 

[wushaw]

I used 4" channel for my 4X8 single axle dump trailer. It works fine.
All I did was ask my steel supplier and that is what the trailer builders use for that size trailer.
Your 5X8 may need 5" but it's hard to say. Ya may want to stroll over to a trailer lot and measure a frame or two to get a good idea as to what the manufactured trailers are using or ask your steel supplier as I did.

 

[77bronco]

If you go to the Big Tex trailer web site, they give the steel size they use and the measurements of each of their trailers. That would give you almost all the info you might need to start on your own trailer.

Utility Trailers, Dump Trailers

 

[bobodu]

This sure looks rickety, but hauled many many loads of wood,manure and black dirt (one cubic yard at a time) before I built my dump truck. Since you're not planning on hauling 30 ton of limestone, a nice heavy wall 4 inch C channel would probably be okay. This trailer was made from THIN wall 2 x 4 box and held up. Not the choice I would make today....

 

[bx24]

I used 4" channel for my 4X8 single axle dump trailer. It works fine.
All I did was ask my steel supplier and that is what the trailer builders use for that size trailer.
Your 5X8 may need 5" but it's hard to say. Ya may want to stroll over to a trailer lot and measure a frame or two to get a good idea as to what the manufactured trailers are using or ask your steel supplier as I did.

Along those same lines of going to a trailer lot (where they may or may not be happy that you are there with a measuring tape), I was able to go over to the local Lowes and check out some of the rental trailers they had parked (and chain locked up) in the parking lot. No one said anything as I took lots of measurements and pictures all the while raising and lowering the mechanism with the on-board batteries.

 

[wushaw]

I'm sure Lowes wouldn't care since they ain't sellin them and the employees there wouldn't care one way or the other.

The lot I took many pictures of was were I had a coupler put on my 4x8 utility ( before I had a welder) and I will probably be purchasing a trailer from them in the near future, they never said a word to me for taking pictures.

Which type of dumping mechanism are you thinking of going with...scissor, single actuator or dual actuator.

 

[Hookblock]

I made my 5'x8' out of 5" channel, it held up well hauling and dumping wood. Never built a trailer before, got a lot of good ideas from the site.

 

[tatra805]

my 2 cents

if you go look at commercial car pulled trailers you'll end up with a too light construction. Go to agricultural machine stores or measure up an old military trailer.

On road hauling is whole other thing as offroad hauling.

And i saw a lot of trailers made, wondering how they ever will hold up if in my hands. The main motivator for the constructor being able to keep it light so he has a bigger payload on offer for less cost.


I agree on the tipping center being close to the tipping point. You can trick it a bit by doing what i did . See pic.
Drawback is ground clearance when tipping but i didnt have too much trouble in reality with it till now.

benefit is that you can hand-handle the trailer even when loaded. With a tongue heavy trailer that is not the case.

I'll leave some dimensions although metric. millimeters

Bottom frame: U channel 100x50x5
top frame 60x60x3 box channel, all others 40x40x3

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