Thomas Kaiser wrote: > Today I measured the time (with a stop watch) to move 200 mm in > full speed (G00 Z-200.0) and got +8 seconds. Looks like the it > does not move at 3000 mm / min.
> [EMCMOT] > EMCMOT = motmod > SHMEM_KEY = 111 > COMM_TIMEOUT = 1.0 > COMM_WAIT = 0.010 > BASE_PERIOD = 100000 > SERVO_PERIOD = 1000000 BASE_PERIOD = 100000 means you can never move faster than 100 microseconds between each step pulse. That is 10000 step pulses per second. > [AXIS_0] > SCALE = 400.0 Max step rate of 10000 steps/sec, divided by 400 steps/mm, means a maximum speed of 25mm per second. At 25mm/second, it will take 8 seconds to travel 200mm, exactly as you measured. > MAX_VELOCITY = 50.0 But your configuration is asking for 50mm per second. It is impossible for the step generator to generate that speed. It will fall behind the commanded position and cause a following error - unless you set the following error limit to a crazy value: > MIN_FERROR = 10000.0 The following error limit tells EMC "if you ever find yourself this far away from the proper position, STOP!" When you set following error to 10000mm, you are telling EMC "it is OK if you cut 10 meters away from the proper location". NOT GOOD! If you get following errors, you should NOT fix them by raising the following error limit. You should figure out the real reason for the errors and fix it properly. I think the reason that the jogs are running after you stop is that the commanded position (moving at 50mm/sec) has gotten ahead of the motors (moving at 25mm/sec). After you release the button, the commanded position stops, but the motors keep running until they catch up. Fix the speed problem and the crazy following error limit, and the jog problem will fix itself. > After writing so much, I hope you don't get tired reading it ;-) No such thing as too many facts! Regards, John Kasunich ------------------------------------------------------------------------------ This SF.net email is sponsored by: SourcForge Community SourceForge wants to tell your story. http://p.sf.net/sfu/sf-spreadtheword _______________________________________________ Emc-users mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/emc-users
