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General Mach Discussion / Spindle speed not accepted

« on: March 13, 2015, 03:49:15 PM »

Hi

I have just started converting my Dyna Mechatronics 4400 to Mach3 (I will go with Mach4 later on when it has matured a bit).
I have a problem with the spindle speed.

My Setup
* Mach3 R3.043.066
* Ethernet Smoothstepper (ESS_v10h2d1a.dll)
* Windows XP Pro SP3 x86
* CNC4PC C23 breakout board. Using onboard analog output controlled through step pin (port 1 pin 14)

If I enter a speed in the Spindle Speed field and press Spindle CW F5 the spindle starts at correct speed. Also, when I press the spindle override buttons, the spindle speed changes.
So far, so good.

Description of problem
If I enter S1000M3 in MDI mode, the spindle starts, but at the wrong speed. The entered speed (1000) appears in the Spindle Speed field, but wrong speed.
If I change Spindle Speed Override just by one click, the speed changes and ends up correct.

The same thing happens if I run a program in auto, i.e. the spindle speed does not get correct until I increase/decrease override.





I have no idea if this problem is relate to Mach3 or the ESS, so I will post this into both forums. Has anyone else experienced this? May there be something wrong with the configuration?

2

General Mach Discussion / Step/dir + ESS spindle acceleration/deceleration

« on: July 21, 2013, 03:06:54 PM »

Hi

The DC servo driver for my spindle motor does not not have configurable acceleration/deceleration ramp. I guess the original CNC system of my machine took care of the ramping.

I am now converting to Mach3 + Ethernet Smoothstepper + cnc4pc C23 breakout board. The analog out is configured as step/dir (as needed for the C23) in the ESS config. When starting/stopping the spindle, the level of the analog out is changed instantly causing the driver to try to accelerate/deceperate the spindle almost infinitely fast. When stopping the spindle (or decreasing the speed a lot), this fast deceleration causes the driver to trip due to overvoltage (the spindle motor now "produces" current instead of "drawing").

I have tried to slow down the acceleration by adding a 2nd order low pass filter between the analog out of the C23 board and the analog in on the driver, and this would probably work if I fiddle enough with the values. A better solution though, would be if I could just set a suitable accceleration/deceleration (preferably in rpm/s) in Mach3.

There is another solution, and that would be to simply disable the spindle driver letting the spindle coast to a stop when a "spindle off" command is issued. I don't really like this solution, and I would still have problems with overvoltage when decreasing from high speed to low speed without stopping the spindle.

I have looked everywhere in Mach3 but can not find any setting for this. Is there any way of achieving this, or should I maybe place a request for the next update of Mach3?

I'm running Mach3 v 3.043.062.