On Tuesday 07 August 2018 16:49:27 Chris Albertson wrote: > I don't see how rotating the part 45 degrees can help. I would thing > all it does is move the defect 45 degrees. If you are cutting a > shrill groove to make a lathe chuck then you need to make multiple > ful. circles.
No, not at all. Once the tool is out of the materiel, you can lift to clear and step directly to the other side of the jaw, drop back to depth, offset the cut half the pitch, and repeat the exact same code in the relative mode to make the next groove inward or outward of the one you just cut. > I think the best way might be to use four axis and put the material in > a rotary table and make the lath chuck on what is in effect a lathe. > You can make a perfectly round check that way with not axises > reversals. If your rotary can be sped up while carving the air between the jaws, enough to regain the exec time speed, mine cannot. About 2 revs/minute is all I can trust it to do. > On Tue, Aug 7, 2018 at 1:27 PM Gene Heskett <[email protected]> wrote: > > On Tuesday 07 August 2018 13:41:18 Chris Albertson wrote: > > > Yes, that is the method I would use: Create the full scroll then > > > use that as a "tool" to > > > remove material from a black jaw model. You could never get it to > > > match up otherwise. > > > Just last night I needed to make a lid for a box and wanted an > > > interlocking goose. So > > > I make the lid about 10 mm to tall and use the box to cut off the > > > excess. > > > > > > But there is one problem with the technique, especially when > > > making metal parts, you need > > > some clearance. This is why there is an "offset" tool to reduce > > > the size of the part by a few > > > 0.01 mm or whatever you need. > > > > This brings up an argument against doing it aligned with an axis but > > s/b aligned at 45 degrees so there is never an axis direction > > reversal while the tool is within the material. Its been my > > experience, with the quality of machine and ball screws I can > > afford, that one can never get a completely invisible axis reversal > > although I do have bearings seated in such carvings, carved on a > > micro-mill after very carefully setting the XY axis's backlash. > > Sure, lay it out and generate the code aligned with an axis just > > because its easier that way, but mount the jaw holding vise at > > nominally 45 degrees, measure its angle with a touch probe and sci > > calculator, and rotate the co-ord map to match. That will move any > > direction reversals to outside of the workpiece. Voila! Perfect > > curves w/o any backlash artifacts. > > > > > But is you mill good enough to cut a spiral? Getting the g-code > > > is the easy part. > > > > > > > If you draw the spiral in cad, then choose a section of maximum > > > > radius, and minimum radius that a jaw 'tooth' will traverse. > > > > > > > > Now superimpose those two profiles and lop off any excess, > > > > keeping only the intersecting area. > > > > Repeat for all jaw 'teeth' > > > > Then hand code the segments.. > > > > -- > > 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) > > Genes Web page <http://geneslinuxbox.net:6309/gene> > > > > > > -------------------------------------------------------------------- > >---------- Check out the vibrant tech community on one of the world's > > most engaging tech sites, Slashdot.org! http://sdm.link/slashdot > > _______________________________________________ > > Emc-users mailing list > > [email protected] > > 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) Genes Web page <http://geneslinuxbox.net:6309/gene> ------------------------------------------------------------------------------ Check out the vibrant tech community on one of the world's most engaging tech sites, Slashdot.org! http://sdm.link/slashdot _______________________________________________ Emc-users mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/emc-users
