Hi Jon, > On 02/16/2020 06:10 PM, John Dammeyer wrote: > > Hi Sam, > > Nice. But it does seem to support my premise on isolating LinuxCNC from > the hardware control. > > > > For example, way back a Pentium 386-66 with WIN-95 and MACH2 CNC was > able to do this at 25KHz stepping. > > > > A BeagleBone Black with Machine Kit has PRUs to do the stepping and it's > what, 4 years older than a RPi4? > > > > You�ve already shown that for a 1GHz+ LinuxCNC system that with an > external Ethernet Hardware engine you can now get faster stepping rate . > > > > But only 10K steps/second on a 1GHz+ Pi? > > > Well, I really don't think software stepping is a good > solution except for desktop "toy" machines of very low > performance. I've been making a step pulse generator for > EMC/EMC2/LinuxCNC since 2002. It can > go up to 250K steps/second on all 4 axes at the same time. > It can provide far finer timing resolution > that any software stepping code, even the Beagle Bone's > PRU. (Step timing resolution is 100 ns.) > > Even better than that, I also make controller/interfaces for > analog velocity servos and PWM servos. > > Jon
I think that supports my position that LinuxCNC is really just a middle box between display and motion hardware and if you want optimal performance you offload the real work to something that isn't LinuxCNC. So that fits in with my suggestion that a box with display showing DROs etc, push button panel and MPG knobs that could be stand alone for manual operation is totally reasonable and if you wanted G-Code interpretation you add a PC that adds that set of velocity/accel sequences. I've been asking on other metal working groups about CNC and it's really amazing how few CNC installations there are out there. Many people are happy with a DRO and power feed on one or two axis. John _______________________________________________ Emc-users mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/emc-users
