Ha ha.. I saw you and Rob raising hell on the Mach3 email list.. ;-) That was a very interesting exchange, and Art jumped in, which was nice.
The results are VERY interesting. The accel violations; Mach3 has always bent the rules a bit and gotten away with a lot of stuff simply because stepper motor drivers will tolerate some crap being thrown at them. I'm surprised that you don't see more accel violations! But once you get away from step and direction control and enter the servo world an entirely different realm is entered. That of course is where LinuxCNC takes a right turn and Mach3 makes a left turn. Mach3/4 is reliant upon an outside device absorbing the time/position data and properly closing the servo loop, which is a huge responsibility fraught with issues. Some of the early adopters who used Mach3 with outside 3rd party servo controllers got seriously burned. I'd be shocked if more than 5% of Mach3 users are controlling servo drives via analog controls. If you feed step and direction signals to a smart servo drive they can also greatly alter the end result. Even the cheapest smart drive ( I don't consider Gecko servo drives to be smart ) I have used has jerk limiting built in which will take the edges off those accel spikes/accel violations. But that can also cause motion deviations away from the defined Gcode path. Dave On 2/24/2014 11:03 PM, sam sokolik wrote: > I am surprised people still put up with me... I do have a lot of help > from the community. The compact 5 configs using the latch and dual > stepgens would not have been possible if not for Jeff and Chris's > smarts.. (I am the big picture guy usually...) > > As far as machs acceleration violations. I am pretty confident that > they are real. (again unless I am doing something wrong) If you want > to see some huge violations - run the tort.ngc program. It has lots of > diabolical motion. (granted - it is diabolical) I think though you > should be able to throw any gcode to a control and is should process it > correctly. > > g21 > G0 X0 Y0 Z20 > G0 X5.394910 Y13.495489 Z20.332291 > G19 G2 F500 (225 29) J5.656854 K5.656854 X10.394910 Y26.080547 Z29.989145 > G19 G2 (75 14) J-0.258819 K-0.965926 X6.894910 Y26.787653 Z29.282038 > G17 G2 (329 285) I-4.330127 J2.500000 X3.858878 Y24.458024 Z31.282038 > G0 X0 Y0 Z20 > m30 > > when run through mach and logged shows this > > http://electronicsam.com/images/KandT/testing/MachViol.png > > that is 100 in/s^2 when it should be obeying 30. > > This is what it looks like > > http://electronicsam.com/images/KandT/testing/MachViol1.png > > sam > On 02/24/2014 03:55 PM, John Alexander Stewart wrote: >> Sam, this is really interesting. You have a very creative mind, with this >> and your Emco Compact-5 CNC adaptions, etc. >> >> I wonder if your interpretation of Machs' avoidance of acceleration limits >> is one potential of the "Mach looses steps" issue that I have read about? >> The first time was in a publication where the author put a mechanism to >> test if the Z axis was "slipping" towards the work (if I read it correctly). >> >> John. >> ------------------------------------------------------------------------------ >> Flow-based real-time traffic analytics software. Cisco certified tool. >> Monitor traffic, SLAs, QoS, Medianet, WAAS etc. with NetFlow Analyzer >> Customize your own dashboards, set traffic alerts and generate reports. >> Network behavioral analysis & security monitoring. All-in-one tool. >> http://pubads.g.doubleclick.net/gampad/clk?id=126839071&iu=/4140/ostg.clktrk >> _______________________________________________ >> Emc-users mailing list >> [email protected] >> https://lists.sourceforge.net/lists/listinfo/emc-users >> > > ------------------------------------------------------------------------------ > Flow-based real-time traffic analytics software. Cisco certified tool. > Monitor traffic, SLAs, QoS, Medianet, WAAS etc. with NetFlow Analyzer > Customize your own dashboards, set traffic alerts and generate reports. > Network behavioral analysis & security monitoring. All-in-one tool. > http://pubads.g.doubleclick.net/gampad/clk?id=126839071&iu=/4140/ostg.clktrk > _______________________________________________ > Emc-users mailing list > [email protected] > https://lists.sourceforge.net/lists/listinfo/emc-users ------------------------------------------------------------------------------ Flow-based real-time traffic analytics software. Cisco certified tool. Monitor traffic, SLAs, QoS, Medianet, WAAS etc. with NetFlow Analyzer Customize your own dashboards, set traffic alerts and generate reports. Network behavioral analysis & security monitoring. All-in-one tool. http://pubads.g.doubleclick.net/gampad/clk?id=126839071&iu=/4140/ostg.clktrk _______________________________________________ Emc-users mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/emc-users
