Thanks Technico, I think I will try something like that. How thick of steel plate do you think I would need? 1/4 inch? I am now the proud owner of a very large chunk of cast iron. They will load it with a forklift at the other end. My driveway is a bit sloped, so this weekend I'll have to put an anchor in the back of the garage. Did the trailer angle up on its own when the mill went on?
@Maker Mike Happy to help out, I learn plenty here and it's fair return wherever I can find something give back!
Did we ever determine the weight of that beast? I sized my rig for the 2200lb of my First so if your machine is heavier then you'd need to see if the difference would need to be adjusted for.
The 4" angle I used was 1/4", the 2 x 2 square tubes were 1/8" wall. Those would be easy to beef up if needed just by changing the section thicknesses.
The wheels are rated at 720 lb (PA sourced).
If you look at the 3/8" flange plates on the ends of the 2 x 2 tubing where they bolt to the 4" angle you see one bolt at each bottom corner, there is a third bolt you don't see between them that passes through, just clearing the wall inside the tubing. I needed all 3 in my design for strength. I only needed one at the top since the joint is in compression there and all it would carry would be shear load. This is all bolted together to allow for it to be assembled in place around the machine while the it's up on blocks.
The 2 x 2 tubes are welded to the flange plates with as close to a complete joint penetration weld as I could achieve so they're not just fillet welds. The tubes were ground with a chamfer before welding. Same for all the welds actually.
I used 1/8" for the gussets that tie the (horizontal) castor positions to the verticals of the 1/4" angle. There are gussets both in front and behind the castors and both are needed. With them in place the castors fit into sort of a pocket but they make sure the load is well transferred from the castors to the dolly frame and the 2 x 2 tubes. If your machine is heavier you might need to make the gussets thicker but that's easy.
I recommend making only two of the wheels castoring and doing the steering.
OK, loading. I didn't notice the trailer moving while loading or unloading. To load I drove the back wheels of the truck up on blocks to raise the tongue. For unloading, there was no point in raising the tongue because my shop threshold is a little higher than the driveway so I just dropped the ramp on the floor and moved the machine off.
@Rauce mentioned the trailer ramp not being strong, I laid pieces of 1/8" plate on the mesh of the ramps to protect it. You will want to have a piece of plywood or metal plate in the bed of the trailer too so the castor wheels don't hang up in the corrugations of the bed. Once on board I set the dolly up on wood blocks to get it up off the wheels to discourage it from moving during the trip.
If you can get an anchor point installed in your garage you'll be one step up on me, I'm still thinking about how to retrofit my shop!
Congrats on your acquisition, I'm looking forward to hearing about the move and getting the machine up and running.
D