On Tuesday 07 August 2018 17:11:11 Gene Heskett wrote: > 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 by 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. edited above to correct mistake, its not half. My bad.
> > 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
