On Wednesday 17 June 2020 21:41:07 andy pugh wrote: > On Thu, 18 Jun 2020 at 02:23, Gene Heskett <[email protected]> wrote: > > There's a parametric gear thing I have but its a sample of many gear > > styles and I don't know how to cut it apart and use just the > > external spur piece of it. I need something that openscad can > > handle. > > You could take OpensCAD out of the loop, I suspect, and print the > gears from the stock part models from (for example) McMaster Carr > > Or you could tell me the centres, tooth size and PCD you need and I > can send back a model from Inventor in not much time. > That (centres) I don't know yet, and won't until I can get the intermediate idler shaft made & installed.
> But why use spur gears? One thing that 3D printing is good at is > double helicals. That thought crossed my mind also. Seems to me the thrust would nicely balance making it self center, and the rotational accuracy would be improved over a straight spur gear. But for any of them I need the center distances, hard to measure in its present state. And I'm stuck waiting on Digi-key to mail me a 10 pack of ATS-667's ATM. > Or even triple, or quad. But those are stupid: > https://images.app.goo.gl/ZbZBVWoBEnRbPL469 > > Note, these are a daft idea. But I have actually seen a 9 foot > diameter triple helical in my dad's old workplace. He did need to > explain to me why it was silly, and why they refused to replace it and > specced a double instead. That's easy, the teeth in the middle were carrying twice the thrust load. Thanks Andy. Cheers, Gene Heskett -- "There are four boxes to be used in defense of liberty: soap, ballot, jury, and ammo. Please use in that order." -Ed Howdershelt (Author) If we desire respect for the law, we must first make the law respectable. - Louis D. Brandeis Genes Web page <http://geneslinuxbox.net:6309/gene> _______________________________________________ Emc-users mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/emc-users
