Utility Trailer

Seems like forever since I've posted, So I believe its about time, right?
So, I've gotten the idea that I'll just build a bulletproof mower, bumpers, guards, big tires, you guys know the drill by now.. Only thing I wont be doing, is speeding it up. I dont really wanna lose any pulling power and plus, If thing is towing a couple hundred pounds at lets say...20(?) Thinks are gonna get hairy real quick if that trailer turns over.

So, my Question to you guys are.. if the settled trailer dimensions are 6x4x1 (Length Width Height)

What could I build this thing out of? I have two old bed frames laying around, can I use those? I've read these things are brittle, not easy to weld, and just make beads crack easier(?)

I have both a 1in axle and bearings laying around, and a 3/4 in in my shed. the 1 inch has bearing that are stand alone, kinda like FearlessFront's Gokart build. the 3/4 has a housing where the ends taper up to house the bearings, plus I have huge tires for 3/4 axles since it's standard mower diameter.

Both axles are pretty short. The 1in is about 38, and the 3/4 is 37 (The housing its self is 28.5) Could I possibly lengthen these? Sleeving them, of course.

If I was sparce on material, could I put the center bars every two feet? (three center bars for 6 feet)?

I have a murray widebody that has those C (or U) frame rails, could I possibly use one of these as a tongue? My Utility cart thing (bought from Lowes) has one with that same general shape. I would of course, brace it a bit to reduce the flex.

Let me know your opinions, or maybe something to add to this thing!

Cant wait to see it come along. A trailer or anything is as strong as you build it. I checked local steel supplyer and 1 x 1 x 20 feet steel tubin was 15 dollers or so.

I should snap a few pics of my homemade trailer, it's about 2.5'x5'x2' in size, it will give you some ideas the frame is 2" square tubing and there is one inch steel tubing for sides, that the plywood is bolted to, I used the fleet supply store 4 bolt trailer hubs and weld on spindles (used but same thing) the tongue is also 2" square and the hitch is a pin style that is too flimsy it already bent once when the trailer came unhooked.

Only complaint I have is it needs bigger tires.

If I bolted the plywood on mine as well, wood it be a big problem? ANy ideas on how thick? Im leaning towards the fact of the 1 in axle, since Its already a bit longer, and it's got good tires on it..