I'm not sure if this is what is meant by "rest" but my AlibreCAM (Mecsoft VisualCAM) lets me do this I think.
I've created a small part with some curves and recesses. No point to it other than I made it up as I went along using AlibreCAD. Then I started AlibreCAM and set up a roughing and finishing operation. I believe the roughing leaves a tiny bit not milled. I used the same toolbit (6.35mm for both). http://www.autoartisans.com/mill/Tray1-Roughing.jpg The roughing cleans out the inside and outside of the block then the finishing just cleans the edges. For the roughing step down was 10% of tool diameter so there are a lot of passes. Probably should have done it with 25% to 50% for this example. http://www.autoartisans.com/mill/Tray1-Finishing.jpg Is this what is meant by "REST"? Obviously I'd want to use a ball mill for the curved section in the center and the fillets on the outside to get the best finish. But the 3D finishing pass only covers the edges. This was all whipped out quickly and since I'm way far from even close to knowing what I'm doing there may well be better ways. John > -----Original Message----- > From: Chris Albertson [mailto:[email protected]] > Sent: July-24-18 5:45 PM > To: Enhanced Machine Controller (EMC) > Subject: Re: [Emc-users] CAD for LinuxCNC > > It is not clear if your method would work in the general case. "rest" > seems easy of doing a "waterline" type operate on a 3-axis mill. But what > about a 5-axis machine? > > I think the best way to program a rest tool path is to first transform the > part into a larger part thais is only roughed out. You might do this by > moving every surface out in the normal direction my some amount like 1mm. > The you make that part using a roughing cutter. Then swap cutters and > make the part as per the 3D model. I don't think you need simulation. > But you do need to be able to move the surface out in the direction of the > surface normals. > > On Tue, Jul 24, 2018 at 1:24 PM Roland Jollivet <[email protected]> > wrote: > > > On 24 July 2018 at 22:02, Sebastian Kuzminsky <[email protected]> > > wrote: > > > > > On Tue, Jul 24, 2018 at 1:45 PM Valerio Bellizzomi <[email protected]> > > > wrote: > > > > On Tue, 2018-07-24 at 21:27 +0200, Roland Jollivet wrote: > > > > > I had a quick look at PyCAM, and FreeCAD's Path Workbench. > > > > > > > > > > >From what I see, neither seem to do rest milling (rest machining), > > > which is > > > > > a limitation of most of the free packages and makes it pretty useless > > > for > > > > > multiple cutters unless you are extremely vigilant on what was not > > cut. > > > > > > > > > > Or do they do rest milling? > > > > > > > > I have no idea of what it is, but there is a feature request: > > > > > > > > https://github.com/SebKuzminsky/pycam/issues/120 > > > > > > I think "rest machining" refers to doing initial machining passes with > > > a large-diameter cutter, having the CAM keep track of the remaining > > > material that needs to be removed, and then doing finishing passes > > > with a smaller-diameter cutter to remove that remaining material. For > > > example, think of a large pocket with sharp corners, roughed out with > > > a large endmill and then finished with a small endmill. > > > > > > The feature request you linked above is different (and simpler): it's > > > just to do "normal" machining operations on *select* features in the > > > model, instead of applying the operations to *all* features of the > > > model. > > > > > > > Yes. When milling steel it's very easy to snap a 3mm cutter because the > > previous 6mm cutter couldn't go into a dip, and the path is using the final > > geometry as the reference model for the 3mm cutter. > > > > I've often wondered how hard it would be to program 'rest machining' > > I think stl format is fine for most hobbyists, and offers a simpler way of > > keeping track of a solid in software. > > > > A method I envisage is as follows; > > Say operations are chosen as follows; > > - first a 10mm roughing, then > > - 3mm finishing with 0.2mm remaining, then > > - 1mm final pass, 0mm remaining > > > > Once all the parameters are selected, the software creates a machining > > model in Reverse... > > First it takes the final .stl and adds on a 0.2mm layer, by computing > > triangles according to the path of the 1mm cutter parameters, then > > adds the 3mm passes, and so on until the full stock has been generated. > > Obviously now these operations are run in reverse again to create a forward > > Gcode file. > > > > Possible? > > > > ---------------------------------------------------------------------------- -- > > 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 ------------------------------------------------------------------------------ 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
