VBRAB
"Surprisingly the engineer advised not to fully weld, but to weld along edges, but not across the flanges. "
This is not surprising at all, welding across the flanges will induce failure quicker than you can blink.
Aluminium is very very very flexible unlike steel which is only very flexible. The trouble is Aluminium work hardens as it flexes. Hardening is compounded by the Heat Affected Zone of welds. If you weld across the flange at the transition those welds will crack quickly. By extending the decking 700mm onto the a frame you will be helping move the transition from a location of beam junctions to mid span of beams. Ensure that the front storage box is tied back rigidly to the main box.
Although you have lengths running from hitch to rear, there will still be a transition between the boxed section of trailer (very rigid due to triangulation of box) and the 180mm high chassis rail.
I can see that the A-frame and chassis are one unit but that does not preclude the differential in flexing between boxed in main section and drawbar section.
I would think you will find that transition your weakpoint and that the use of trussing may be advised.
If you use a 50mm hitch at a height of 450-460mm the trailer will not meet Australian Design Standards VSB1. They stipulate a hitch height of 270mm to 350mm for 50mm ball couplings. So either alter the height or DONT use a 50mm ball coupling.
S
'95 130 dual cab fender (gone to a better universe)
'10 130 dual cab fender (getting to know it's neurons)
Bookmarks