Issue jogging in 0.001mm steps in Mach3 with Sieg KX3

[Nicola CasaliParticipant @nicolacasali98042]

[Nicola CasaliParticipant @nicolacasali98042]

Ok, so jogging in 0.001mm steps doesn't appear to move my Y axis, despite the DRO incrementing and decrementing by that amount. That's using the arrow buttons on my keyboard. Moving in those increments is not practical, anyway, right?

But my iMach P4-S pendant does use 0.001mm (actually it's 0.002mm) steps in velocity mode, when moving the wheel slowly or at the beginning (or end) of an acceleration when getting up to speed in velocity mode. [edit: I assume it's using those microsteps anyway between point A and B] When moving the wheel slowly, I note that I can change the DRO and not get any stepper motor motion. Also, doesn't that affect g-code too?!

Anyone have any ideas what's going on with jogging very small steps? How do I prevent the DRO from changing when no steps are being output to the stepper motors?

Edited By Nicola Casali on 10/06/2021 16:01:41

[Anonymous]

Posted by Nicola Casali on 10/06/2021 15:49:44:

Moving in those increments is not practical, anyway, right?

No it isn't practical. On my CNC mill the smallest theoretical increment (smallest step on the motor) is about a tenth of a thou, or 0.00254mm. The motor can be heard stepping but the table doesn't move for several steps (as indicated with an edge finder) due to stiction and backlash in the ballscrew.

I no longer run Mach3 so can't comment, at least not in polite mixed company, but In PathPilot the system doesn't lose steps even though the DRO might increment but the table doesn't move. It all comes out in the wash as long as the system keeps track of motor steps in machine space. The DRO isn't measuring anything. It simply displays a number based on a zero set by homing the machine at startup, the number of motor steps made and a fixed translation based on the ballscrew pitch and motor steps per revolution.

Andrew

Andrew

[JasonBModerator @jasonb]

I seldom use it but it will move on alternate clicks so 0.002 as indicated on the screen using both the mouse and keyboard.

First look at the dti is using the mouse on the Mach3 screen arrows then the keyboard at the end.

As it is such a small amount make sure you have taken up any backlash before measuring table movement. If you turn up the volume you can hear the mouse clicks

[JasonBModerator @jasonb]

Is it just the Y axis that won't do it? Is that the same axis you were having problems with a few weeks ago?

[Tony Pratt 1Participant @tonypratt1]

I used to find on £100K plus CNC machines they wouldn't move by .001 mm steps so don't stress about it.

Tony

[Nicola CasaliParticipant @nicolacasali98042]

Copying JasonB and using the mouse to jog any axis, all axes change the Mach3 DRO by -0.002mm, as long as it's negative. I can't get any DRO axis to change positively or steppers to move. The X+, Y+ and Z+ buttons do nothing.

The X-, Y- and Z- buttons change the DRO by 0.002mm, on alternate mouse clicks. The X and Z axes steppers also appear to move the carriage or column by 0.002mm on alternate clicks, but haven't measured but can hear. The Y stepper doesn't do anything, despite the DRO changing.

It's not keeping track of Y in machine space. Why not? Yes, it's a Y axis problem again.

Edited By Nicola Casali on 10/06/2021 17:04:20

Edited By Nicola Casali on 10/06/2021 17:05:06

[Nicola CasaliParticipant @nicolacasali98042]

JasonB, could there be something in my Mach3 XML file that is causing Y to behave differently? Or could it be a stepper driver issue?

[JasonBModerator @jasonb]

I'm not sure Nicola. But I did just fire mine up again and it jogs in moth directions in all axis

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