HA!!!!
UHMW , otherwise known as Ultra High Molecular Weight, plastic. I know it VERY WELL. One of my overtime assignments in the San Diego Fire Department was outfitting brand new fire trucks, to prep them for service. We used MILES of UHMW for years and years in all sorts of shapes, sizes, thickness's and more. Yep, you can do all the drilling and tapping and all that but, one thing that we really wanted to do with it, YOU CAN'T. And that is, you cannot WELD IT. We learned that for about 1/2 the cost and about 3/4 or more of durability, strength, user friendliness and all that, you can get HDPE plastic. High Density Polyethylene. If you don't know about it, in appearance, it's identical. And, it can be WELDED. We made boxes and a whole lot more out of that HDPE. Anyway, glad you got your system working with the UHMW.
I retired 10 years ago and still have a small box of both UHMW and HDPE pieces. I use it quite often for all kinds of various little projects. It's so fun to work with and, so incredibly strong. The only problem with normal HDPE or, UHMW is, neither are UV resistant. Yes, they'll last for a while but, exposed to direct sunlight, they will both deteriorate over time to the point they'll crack. No biggie, it takes quite a while for that to happen. Good luck.
Scott