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.
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. 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 > -- Chris Albertson Redondo Beach, California ------------------------------------------------------------------------------ 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
