Trailer build question

[handirifle]

There is a local steel supply shop that sells used steel round pipe in various diameters. It is usually dirt cheap compared to new steel. I got this idea of using stacked tubing (3" or larger) for the frame with gussets welded to make them as one piece or close.

I am thinking of something along the lines of a 7x12 flat bed capable of 4,000lbs or less. Use it to haul my Massey Furgeson 1010 or riding mower or lumber or firewood. I have a 4x8 utility that is very heavily built, that I mostly use for hauling fresh cut firewood, but it has 16" sides and a flat bed would be a nice addition. I have hauled 2 complete pallets of used brick on the 4x8 with zero issues. Tires are rated for 3500lbs combined.

Is this a lame idea or decent? I am not sure what wall diameter of the pipes are but I can easily find out tomorrow with a phone call. What thickness should I look for?

 

[oosik]

I built a ten ton farm wagon that used 3" round pipe. The running gear is manufactured by Horst. Its not quite what you have in mind but the pic may give you added ideas. The pipe in this pic has 1/8" wall thickness. I do not have a welder so I had to purchase the entire running gear kit. The two pipes are the total support for the wagon while the front & rear axles carry the load.

View attachment 453298

 

[Travelover]

Tubing makes a great frame, look at any race car. It just takes more work than flat pieces. Tubing has exceptional torsional strength and this is why modern truck frames are a closed box section vs the old C section. A flat piece welded between each end of the tubes will capture this stiffness.

 

[LD1]

Two 3" tubes stacked together provided they arent really thin wall, and gusseted well, should have at least as much if not more strength than 6" channel iron. And getting close to strength of 6x3 box tube of equal wall thickness.

But sounds like alot of extra work and welding.

 

[Mysfyt]

If you do go ahead with this, I would recommend tack welding everything first and fitting as much up as you can before welding. Reason for this is the warpage you'll be dealing with by welding pipe sections in parallel.

 

[Diamondpilot]

Weight will be a issue.

Chris

 

[handirifle]

Thanks for the replies. Better than I thought they might be. I still need to price the tubing and see if it's feasible dollar wise. For connecting the two tubes, I was considering something along the lines of 1.5x1.5 angle iron, but flat might make better sense.

Yea I would definitely "tack" it up before doing big welds and even then I'd skip around to try to control warping.

Would I be able to get away with smaller, say 2" or 2.5" in keeping it under 4ooolbs carry weight, to reduce the trailer weight as Chris mentioned?

 

[Travelover]

............
Would I be able to get away with smaller, say 2" or 2.5" in keeping it under 4000lbs carry weight, to reduce the trailer weight as Chris mentioned?

If you use two pipes per side and separate them vertically, it will be like a small truss and a lot stronger.

 

[handirifle]

How would I do that?

 

[handirifle]

I built a ten ton farm wagon that used 3" round pipe. The running gear is manufactured by Horst. Its not quite what you have in mind but the pic may give you added ideas. The pipe in this pic has 1/8" wall thickness. I do not have a welder so I had to purchase the entire running gear kit. The two pipes are the total support for the wagon while the front & rear axles carry the load.

View attachment 453298

I am no engineer by any stretch, but it looks like those vertical beams running front to back are carrying the main load, with those sitting on the axles. Or is there something there I do not see.

For mine I would have the rectangular box frame, with cross bracing welded about every 4 feet or less to support the 2x floor, and the load on them.