I got a little more work done. First, I took the DOM tubing to a local machine shop, where they reamed it out to the proper size to receive the 1" pin. It cost $25, which is about as much as a reamer would have cost me, but I decided it was worth the cost to have it done right, versus me hacking away at it. All told, the DOM tubing has been the single most expensive part of this endeavor: $12 for the tubing, another $15 for the shipping, and another $25 to have it reamed out. I guess the factory bushings were also about $50, come to think of it.
I drilled the holes with a hole saw, then put the bandsaw in the vertical position and cut straight in to make the "cup" for the top. I have been drilling my holes 1/8" oversize to allow precise placement of the bushings, but for the top hole, I drilled it exactly to size, so that I could hit the 9-o'clock and 3-o'clock position exactly with the vertical parts of the "cup".
Cutting the DOM tubing in half lengthwise to make the bottom of the "cup" was difficult. I finally ended up just pushing it through the bandsaw in the vertical position. I did this before cutting it to length, to give me an extra few inches of tube to grip onto.
Next, I cut the top of the side plate down. We had previously discussed leaving the back of the bracket longer than the front, to allow pushing on the implement to line up the loader arms with the implement. After thinking about how the bracket will be used, I am thinking that it may make more sense to leave the front of the bracket long, to allow for reaching out and picking up the implement, versus pushing into it. For a three-point hitch, which was the original example, it seems like having the back of the bracket long makes sense, because you can't "reach out" with a three-point. You are just going to push into the implement and then lift. But with loader arms, you can reach out and pick up, and it seems that would give better visibility, since the QA adapter would be going underneath the bucket pins.
Next step is to tack weld the bushings in place and then get some flat plate made up to finish the vertical walls of the "cup". But I can't run the grinder while the kid is taking a nap, so I can't weld at the moment. More to come!
