Rear Support Groove
On the rear support measure and layout a groove to accept the axle rod. On the ends I marked the depth of this slot just shy the diameter of the rod. You want the axle to sit slightly high by about a sixteenth of an inch.
Set the table saw fence and run the rear support through the saw a few times. Adjusting the fence a blade width or so each time until the slot is cut.
I removed the excess wood with a half inch chisel. And test fitted the axle.
On the front support I laid out the beveled end and set the angle of my sliding miter saw to match. It’s a shallow angle so I cut it lengthwise with a small support block helping to hold it in place. You could opt to cut this it a 45 degree angle instead if that works better for you.
Once set, I cut the 4 ends of the supports.
Drill a hole in the center of the axle to accept another cotter pin. Cut a groove with the miter saw at that location. This will prevent the axle from sliding or rotating in the groove.
Secure the Axel
I used 6 inch long, 3/8″ galvanized carriage bolts to secure the supports to the base. I’ll use a one and a quarter inch forstner bit to allow the bolt’s washer and nut to recess into each support. You could use longer bolts and not have to do this step.
Layout the front base with the two holes marked on the center line.
Then drill with the forstner bit one and a quarter inch deep.
The same with the rear support but offset the holes on either side of the axle channel. Use the washer as a guide to layout the hole location.
Chuck the 3/8″s bit in the press and drill each hole.
This bit was not quite long enough in the press so I used a portable drill to finish.