Hi Ian, I'll try to reply to the issues you presented below
----- Original Message ----- From: "Ian W. Wright" <[EMAIL PROTECTED]> To: <[email protected]> Sent: Sunday, February 17, 2008 6:04 PM Subject: Re: [Emc-users] Stepper strangeness - mixed up ini? > Ok, thanks Alex, > > I seem to be getting there if a little slowly. I changed the BASE_PERIOD > down to 15,000 and got an error "RTAPI: ERROR: Unexpected realtime delay > on task 1" so I changed it to 20,000 and it is running fine. Sounds good, that's the sensible thing to do. > There is one thing I can't get a handle on - the jog speed of the A-axis > now wants to go in excess of 10,000 which is way beyond the range of the > stepper (its OK up to about 2200). what units are 10000 and 2200 in ? (if it's the speed AXIS reports, read below..) > I changed the MAXIMUM_OVERRIDE from > the 5.0 I had it at to 1.0 and I can get all the motions under control, > however, I don't seem to be able to find a way to set the "Jog Speed" > settings in AXIS to a realistic value. Each time I shut down and restart > EMC2, they go to silly values like 10,000 degrees/sec for the angular > axis and I have to move the slider back by hand to around 2,000. These "large" values are the DEFAULT_* settings in the [TRAJ] section. You should set them to a setting which suits you. Actually I don't remember a DEFAULT_LINEAR_VELOCITY setting, but I might be wrong. Look at a sample stepper_mm.ini from /etc/emc2/sample-configs/stepper/ for how things are set up. > Where > are these values set - I assume that they too must be a complicated > multiplication of several other values?? If so how do you work out a > suitable figure? I would do it like this: set the ini settings pretty high (I guess you already have them high enough). Then do a couple of jogs with increasing speeds, until things seem to stop working. Then back off 10-20% for safety reasons (under load it might not work the same, etc). Remember those values for each of the X,Y,Z and A axes. > Since I changed the BASE_PERIOD, the linear axes atr also moving faster > and I'm struggling to understand how the speed figures are actually > arrived at... for instance, the BASE_PERIOD is now 20,000 and for the > X-axis, the INPUT_SCALE is -400, the MAX_VELOCITY is set to 4.0 and the > speed the axis shows in AXIS when moving under a G0 or Jog is 240 - I > can't get the figures to make sense..... ok.. lets go over things: ini settings are in user units (mm in your case I suspect) (scale) , user units / sec (vel) and user units / sec ^2 (accel). So.. in your case: INPUT_SCALE is -400 (that means 400 steps to get 1 mm), I suspect that's a stepper with halfstepping, taking one complete turn to move a 1mm/rot. screw. Next your X max_vel is 4.0 (that is in mm/sec), that means: 4 * 400 = 1600 pulses / sec. AXIS reports moves in mm/min. because that's the twisted way g-code expects feeds, so 240 is mm/min (actually the same as 4 mm/sec). I would try to jog with different speeds until you find a speed that works right for you (say 180 reported by AXIS), then all you have to do is write MAX_VELOCITY = 3.0 (and 3.5 for STEPGEN_MAXVEL). For accel you should do similar (change the ini, restart emc, and see how it behaves). > Thanks, > -- > Best wishes, > > Ian > ____________ Regards, Alex Let me know if it doesn't work. PS: reading this might help too http://www.linuxcnc.org/docview/2.2/html//config_ini_config.html#sub:INI-Detail ------------------------------------------------------------------------- This SF.net email is sponsored by: Microsoft Defy all challenges. Microsoft(R) Visual Studio 2008. http://clk.atdmt.com/MRT/go/vse0120000070mrt/direct/01/ _______________________________________________ Emc-users mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/emc-users
