Well as I mentioned before, I acquired an axle to mount the splitter on. The top of the axle is 11.5" off the ground, so even taking the 4" deep beam into account the working height would be too low if I sat it straight on the axle. It's also not a great plan to dump a heavy splitter on the middle of a flimsy axle beam. I decided I wanted the top of the beam to be at least 2' high, so I scratched my head, consulted the metal pile and came up with a plan.
The axle beam is 3' wide, with torsion suspension units at each end. I wanted to space the splitter beam up by 8.5", and make sure the weight of the splitter is supported directly above the suspension units.
I dug out a few short lengths of thick wall tube about 1.75" dia, and some more 1/4" plate. My plan was to cut 4 lengths, and attach 2 pieces of pipe each side of the axle, one facing forward and one facing back, a bit like the image below. The tubes will be welded to flat plates that will in turn mount to the axle and splitter beam.
As you can see I had some help from CAD software to figure out the lengths and angles. I had to cut a 65 degree angle on each end of all four pieces of tube. I wasn't going to be able to achieve this angle on the power hacksaw, so I decided to cut the angle freehand with my 4.5 grinder and a slitting wheel.
While searching for tube mitring templates I came across this method,
HOW TO-Pipe Template .
There are lots of calculators on the net for tube coping (where you want one tube to join another), but this was the only one I found that dealt with joining to a flat surface.
I drew myself a template on CAD and printed out full size onto paper, wrapped it around the tube to be cut and drew around it with marker pen. I held the tube in the vice and freehand cut to the line. Since I needed the same angle on both ends of the tube some careful measurement and alignment was necessary to match both ends.
First my template construction geometry, and the cutout template.
The tube with the template, then wrapped around, and marked with a Sharpie.
And the end result. Obviously this would have been a whole lot easier if I could have done it in the saw!
The next challenge was to figure out how to stick all these pieces together in the correct position. I ended up creating a wooden jig using some old 3 fence posts.
I screwed the flat plates to the jigs, held the tubes in their required positions and tacked each piece in position.
Having got these tacked in position, I was impatient to try my new frame under the splitter for a trial fit. I'm pretty pleased with how this has worked out so far.
Next job is to fully weld the tubes to the flat plate. I think I'll clamp the plates to their respective components while welding to minimise heat distortion.
Along with the axle I also acquired a ball hitch. It's old and a little worn, but being of cast construction I'm sure it will far outlast any modern pressed steel type. Here it is, bolted to a length of 2 box section that will be welded the underside of the splitter beam. I've added crush tubes inside the box to prevent the bolts coming loose. Hitch height will end up around 20-21" to top of the ball, a little higher than the average ball hitch over here, but better suited to being dragged over rough ground.
More to follow...