Wow Mustang.
Thats on of the nicer homemade trailers I've seen.

That's a thing of beauty, WS!! Well done.

Well lesseee.... most of it was done by-guess-and-by-golly.  But I started with dimensions from another trailer that I had seen and went from there.

The trailer is a 5' x 8' tilt-bed utility trailer.  I made sure to get one with a welded tube-steel frame instead of the typical angle-iron frames.  It cost a couple hundred bucks more, but is quite a bit stronger.

The cross trees are 60" long and spaced so that there is a clear 16" between the top of one rung and the bottom of the next.  At first this looked a bit too close, but I checked several canoes and found it has room to spare.  The first cross-tree member is ~18" from the bed of the trailer.  That gives plenty of room for ice chests, packs, paddles, food barrels, PFDs, etc.  The uprights are 6" apart on the inside edge (7.25" OC).

The uprights and cross trees are both 1.25x1.265x1/8" square tube steel.  I'm an engineer so I just *had* to calculate the stresses.  Turns out I could have used much lighter stuff and it would have been fine.  But none of the standard publications I used when designing it listed the properties for anything smaller.  I ordered the steel pre-cut, and when I went to pick it up I found out that they had 1"x1" tube steel too... would have lightened things up quite a bit!

Anyhow... the tongue is 2" x 2" x 1/8" tube steel.  I would have liked to used something a little deeper (2 x 3), but that would have messed up the connection point where the tongue crosses under the forward most frame member.  A removable pin there is what keeps the bed from tilting.  Any how... by adding that front diagonal brace, it's all rigid and good.

The uprights sit in 1.5 x 1.5 x 1/8" tube steel sockets welded to the frame, and all the connections are pinned with clevis pins with "hairpin" keepers.  Makes it easy to take apart and reconfigure.  I put another wiring connection harness at the point that the tongue connects to the frame (the pivot point).  That way I can swap out the long canoe-trailer tongue for the stock tongue.

Even though the Scoutmaster insisted that he would never need to haul more than 6 canoes on the trailer, I hedged my bet.  The top of the uprights extend far enough that I can plop another "add-on" cross member onto it in the future.  They typically take two groups into the BWCA on separate permits and separate routes... 2 x 4 = 8.  Gonna need another cross tree some day!

All hardware was from the local Fleet Farm store.  It's great being able to buy tractor parts just down the street 

WS

pghportager,

At the risk of being too prescriptive, I learned a few lessons:

1) Weld up the cross trees first.  Then slip the "sockets" on the uprights (use some tape to hold them in place), clamp the whole thing to the trailer frame, and tack the sockets to the frame.  Remove the cross trees to finish up welding the sockets to the frame.

2) No matter how careful you have been, the cross trees won't just slip into the sockets.  The heat distortion won't let 'em.  So take a scrap off-cut, put some light cutting oil on it, and then dust it with course lapping dust (if you have course lapping compound that should work fine).  Work the piece of scrap up and down in the sockets until it runs free.  You'll probably need a hammer and a couple of hours to get it really cleaned up.

3)  Use an angle grinder with a sanding disk to really clean up the lower part of the uprights to bright metal.  Then put some grease on 'em and see how they fit.  My guess is it will still need some wiggling... mine did!

I took a few photos of details and can provide them, but this board probably isn't the right place (they're half a meg each).   Send me a PM with your e-mail address and I can provide anything else you think may be helpful.

WS