Pipe hanging strap seems a very poor choice for durability and accuracy.
A better idea would be a real under-mount system. Like a half of a metal box, or a shelf that the trackball sits on and is screwed onto in place. Have to be able to take the thing out without too much trouble... as the thing may need cleaning, lubrication, or replacement parts, one day.
I agree that a box or brackets/shelf would be better.
IIRC the original guy had routed his CP down to 1/4" or so and used the strap as supplemental support, not a primary mount. I figured that if MM mounted the trackball to the plexi and added the straps for additional support, it would decrease the odds of the plexi cracking without the better, but more labor intensive, box/shelf.
Now that I think about it, some
angle iron might be easy to make into 4 shelves (one on each side), if the holes line up properly. The piece attached to the panel oriented like a "7", the piece supporting the trackball oriented like an "L" and held to it with 2 bolts/nuts. Bolt heads are next to the trackball, the bolts pass through the "7", then the "L", then the nuts. To disassemble, remove the nuts, then pull off the "L", leaving the "7" screwed to the panel.
Scott