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
