But the thread-mills I used worked out alright for me. Perhaps the people who market Acme-Thread-Mills should be prosecuted for fraud but I won't be joining the class action suit.
If you actually have one, measure it or something. I'd love to be proved wrong. I'd like to swing it and see. If its possible, I'd be happier than a pig in..... mud. At this point, I don't think it is.
I do appreciate the "it has to work". I'm a huge fan of that, and practice it when possible, unfortunately... sometimes.... to pay the bills.... you have to take jobs and sell them to people that actually care if its right. Doesn't have to work, just has to be to print. If I had a dollar for everytime it was to print and didn't work, I'd be rich.
Old biker dude:
Some of you guys would crap when you seen my ghetto fixtures,
I've had them, I still have them, I'll keep making them. I made a nylon surface plate for a job. I actually bolted a 20X40, 2 inch thick nylon surface plate to my machine.
Wood is fine, especially when it comes from a dry rotted busted pallet, those stupid door/window shims are fantastic for taking up a little play here and there, honestly far better
than a jack screw, and I love my jack screws, they can bend a casting or weldment back into shape real quick.
Here is a crappy one I built 8 years ago. The base plate is a scrap part and all the uprights are undersize material bought by a customer.
The guy who was running the shop at the time told me it looked like shit, and it does. Oddly I don't work there anymore and the customer actually bought that giant
mass of crap from my previous employer, along with the 2nd 3rd and 4th op fixtures, used them at least a dozen times in the past few years.
If you can threadmill an internal Acme, show me. I've showed you why I don't think it will work, at least correctly.