On Wednesday 17 June 2020 22:23:23 Chris Albertson wrote: > You can make a double-helical by downloading a left and a right > helical and sticking them together. You do not even need to know what > "involute" means as you just cut and past from McMaster Carr. Just > keep faith that they know how to design exotic stuff like spiral > bevels, they do. > > Designing gears got so much easier when I found that all the gear > resellers give away their designs. > > One other big advantage yo downloading a stock gear is that later when > you need a metal version of thegear, you know you can get one. > > In theory, you should be able to mill these exotic gears on a mill if > only you had a small enough ball end mill. It makes take a week. > > About printed gears. One thing, just don't try for smaller than > about module 1.0. Yes, 0.5 will mesh but the error in shape is high > as they get smaller.
Module is a term I've never met in that context. Where can I find a tutorial on it as applied to gears? > On Wed, Jun 17, 2020 at 6:44 PM andy pugh <bodge...@gmail.com> wrote: > > On Thu, 18 Jun 2020 at 02:23, Gene Heskett <ghesk...@shentel.net> 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. > > > > But why use spur gears? One thing that 3D printing is good at is > > double helicals. > > > > 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. > > -- > > atp > > "A motorcycle is a bicycle with a pandemonium attachment and is > > designed for the especial use of mechanical geniuses, daredevils and > > lunatics." > > — George Fitch, Atlanta Constitution Newspaper, 1912 > > > > > > _______________________________________________ > > Emc-users mailing list > > Emc-users@lists.sourceforge.net > > https://lists.sourceforge.net/lists/listinfo/emc-users 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 Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
