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svenhb / GRBL-Plotter

A GCode sender (not only for lasers or plotters) for up to two GRBL controller. SVG, DXF, HPGL import. 6 axis DRO.
https://grbl-plotter.de/
GNU General Public License v3.0
647 stars 172 forks source link

Stepper motor for pen lift #396

Closed Marmadoc closed 2 months ago

Marmadoc commented 2 months ago

I added stepper motor for pen lifter instead of servo motor. I also add limit switch for pen lifter (Z axis). In software I can setup Z-Height - in mm. I'm looking for gcode generation for example PenUp - move up up to limit - triggered by limit switch and not triggering alarm. Stepper doesn't have feedback position - so I do not know what is current position (after restarting) So is here any possibilities to this scenario: PenUp - move pen to maximum height - limited by limit switch - beginning of code. From now on, I can add PenDown PenZero etc. I'm not talking about homing Z axis. Is it possible?

svenhb commented 2 months ago

I'm looking for gcode generation for example PenUp - move up up to limit - triggered by limit switch and not triggering alarm.

This is not possible via gcode, except "real" homing. Not sure if it works: if you add "$H" to the header gcode, homing will performed, if enabled: https://github.com/gnea/grbl/wiki/Set-up-the-Homing-Cycle You could change grbl-firmware to do homing only on Z axis...

Instead you may want to use "tool length offset". I did it here on a micro switch: https://www.youtube.com/watch?v=x5UTHpgsfII E.g. at 0:33 the tool length will taken via probing: https://grbl-plotter.de/index.php?id=form-probe#toollength

Marmadoc commented 2 months ago

I did it via $H and config.h modification. It works. I expected :-) that you have some kind of hidden magic baton to do that by one click. Tool length - it is new area for me. I will study it soon. Thx for your help