Messages

1

General Mach Discussion / Re: Stepper freeze noise with higher driver kernel speed...

« on: May 14, 2012, 05:01:57 PM »

Hi,

I didn't notice an issue at first with the 45kHz until it tried to move 2 axis at the same time.  Most of my testing was just a single axis before that.  When doing 2 axis at the same time, it would make that horrible seizing up type noise.  I was hoping that there was an explanation for that noise (and that others have experienced it, know what to call it, etc.).  At this point I don't know if it is anything but the driver itself sending commands that don't make sense when it is configured for 45kHz.  I've been tempted to connect up turbocnc and try doing multiple axis at the same time at that speed to see if it does the same thing to prove whether it is a driver issue or something else.

Using 25kHz, I can tell all 3 axis to go at the same time using G00 and they all move perfectly.  I repeated this back and forth at 120 IPM a few times with no problems...

Thanks,

Alan

2

General Mach Discussion / Re: Stepper freeze noise with higher driver kernel speed...

« on: May 14, 2012, 03:28:25 PM »

Hi,

25kHz --> 9.5 to 10.5
45kHz --> 6.x for a bit and bounces up to over 10 every half second or so...

Thanks,

Alan

3

General Mach Discussion / Re: Stepper freeze noise with higher driver kernel speed...

« on: May 14, 2012, 02:42:16 PM »

Hi Gerry,

I understand - is what I experienced an issue that can happen if the kernel speed is set too high?  Have others had the same thing happen?

Thanks,

Alan

4

General Mach Discussion / Re: Stepper freeze noise with higher driver kernel speed...

« on: May 14, 2012, 02:11:10 PM »

Hi Hood,

I agree; 125 IPM is the max I can get with 25kHz and I am ok with that.  I just wondered if others have seen this issue, if it has a name, etc.

Thanks,

Alan

5

General Mach Discussion / Stepper freeze noise with higher driver kernel speed...

« on: May 14, 2012, 08:27:52 AM »

Hi Everyone,

My configuration is a G540 with (3) 381oz steppers using a 48V PS.  I am using an older notebook with a 2GHz P4 which isn't the fastest, but seems workable.

With the driver set at 45kHz - during a fast move (G00) it would do fine with one axis, but if two axis were moving at the same time, it would get part way and for a lack of a better act as if the machine were seized up.  All axis movement would stop and the motors would make this loud horrible noise that would continue until I pressed ESC.  At this point I would usually press the E-Stop and the motors would no longer be held.  I can freely turn all axis so the machine itself is not seized up at all.

Changing the driver kernel speed back to 25kHz solves this issue.  I can move all 3 axis at 120IPM at the same time and it sails along with no problems.

What do you think this is?  Is my system not up to the task of 45kHz?  Could the driver have a problem where it is asking the steppers to fight themselves somehow making this type of noise?  Has anyone see this type of issue before?

Thanks,

Alan