Hi John, Mach3 definitely has a configuration setting to choose between “Exact Stop” and Constant Velocity “ that does what you are describing.
Cheers Peter Peter Homann - (from my mobile) http://www.homanndesigns.com > On 26 Sep 2019, at 4:47 pm, John Dammeyer <jo...@autoartisans.com> wrote: > > I don't believe there are any start/stops/accel/deccel. Watching the mill do > the PathPilot arc compared to the Radius Arc or the IJ arc the motion didn't > 'feel' any different. Probably because the system isn't programmed for exact > stop mode. > > Under MACH3, and I suspect LinuxCNC is the same, you can tell the system to > stop between each move or interpolate between moves to reduce the amount of > start/stop behaviours. > > Say you first went in the X and then in the Y direction at say 5 IPM. In > exact stop mode the X axis would stop and then the Y axis would start. But > using the interpolation mode the goal is to maintain the same SFM so that > square corner really becomes an arc maintained at 5 IPM. Now operation is > smoother, if it's a router there is no burning of the wood, if a mill, no > melting of aluminium onto the tool bit. > > So I suspect the lengths of the straight segments are such that the resultant > interpolation creates the equivalent of the arc. Maybe the path pilot > programmer felt this would create a more symmetrical spiral. As I pointed > out earlier when you look at the LinuxCNC screen grab you can see that the > overall curves aren't evenly spiralling out. > > So maybe that's why? > > John > > >> -----Original Message----- >> From: Brent Loschen [mailto:brent.losc...@gmail.com] >> Sent: September-25-19 10:36 PM >> To: emc-users@lists.sourceforge.net >> Subject: Re: [Emc-users] G-Code issue with IJ >> >> >> �This entire thread has been very interesting to me.� I've learned a >> lot about arc moves and creating spirals, but I'm curious why the large >> number of short G1 moves (generated by PathPilot) is "better" than fewer >> G2/G3 moves?� Seems like a nearly constant feedrate/chipload (similar to >> adaptive clearing) would be better than thousands of >> start/stops/accel/decel - what am I missing? >> >> Brent >> >>> On 9/24/2019 2:45 PM, Ken Strauss wrote: >>> I decided to see what Tormach generates with their conversational >> programming >>> in PathPilot (LinuxCNC pretty face). I don't recall the original parameters >>> so >>> I requested a circular pocket, 0.5 deep, 1.0 diameter, at 0,0, 0.5 DoC, >>> 1/4-inch cutter (what was in the spindle). It spirals down in a 1/2 pocket >>> to >>> full depth and then does a spiral out. I'm happy to try different >>> parameters. >>> (Mill - Circular Pocket G-code generated: Tue Sep 24 16:36:41 2019 ) >> ... cut ... >>> >>> (Spiral) >>> F 15.0 (Arc Feed, inches/minute) >>> G1 X 0.1250 Y 0.0000 >>> F 15.0 (Arc Feed, inches/minute) >>> G1 X 0.1252 Y 0.0110 >>> F 15.1 (Arc Feed, inches/minute) >>> G1 X 0.1245 Y 0.0219 >>> F 15.1 (Arc Feed, inches/minute) >>> G1 X 0.1228 Y 0.0329 >>> F 15.2 (Arc Feed, inches/minute) >>> G1 X 0.1201 Y 0.0437 >>> ... cut ... >>> (----- End of Circular Pocket -----) >>> >>> M30 (End of Program) >>> >> >> >> _______________________________________________ >> Emc-users mailing list >> Emc-users@lists.sourceforge.net >> https://lists.sourceforge.net/lists/listinfo/emc-users > > > > _______________________________________________ > Emc-users mailing list > Emc-users@lists.sourceforge.net > https://lists.sourceforge.net/lists/listinfo/emc-users _______________________________________________ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
