Yes. Im a machinist in a plastic factory and can easily make em myself, just need dimensions
Not so easy as you might think.....
....... The rubber beadlocks have a little squish to them, where a PVC or other hard plastic won't, so sizing will be a little more critical.
Exactly.
Plastic is also much less resilient than the stock rubber part. So in order to keep at least some pressure on the tire beads once everything is bolted in place you will have to be very precise with your WOA. It certainly has to be less than 6-3/4" (post #8 ) since your creation won't compress that much. (unless your material was soft enough, but then - after only a couple days - there would not remain any residual force to keep the tire beads firmly seated.)
Anyway, your base material would have to be a pipe with an ID of 16.0" and OD of minimum 17.25", better 17.5" As said, the exact width will have to be determined by trial and error. Keep in mind that the ends of that cylinder are not cut straight but slightly conical (decreasing towards the center). This is to follow the angle of the beads. Also the stock rubber RF bore is stepped. The outer side is slightly larger, at +/-16.2". That is because the outer wheel half is a bit larger than the inner half.
Having said all that, isn't this like trying to reinvent the wheel...? I really wonder why people (with access to a big lathe) don't simply modify their original runflats by cutting/grinding off the heavy donut portion and keeping just the inner rubber "band" for an (unaltered) beadlock function, just as from factory.
(I may have done a hundred of them, already. Easy enough, IMHO - and cheaper too, I guess...)