Software/hardware Limit Error

[jeremy_smitty]

Ive been setting up my cnc laser engraver, which uses a Grbl interface, to work with a plasma cutter. The three software programs I am using are:

An older version of emachineshop, which still allows export of drawings to Dxf format. I am still teaching myself freecad, which i plan to use as i slowly get comfortable with its interface.

Sheetcam for the post processor of the dxf file.

Lasergrbl to control the actual laser engraving table.

I finally got the table to run its first dxf file, but it came with me having to modify the gcode settings on lasergrbl. It kept saying that the unit reached its “software limit”, according to the dxf file. I made sure to setup the material sheet size so it was actually a smaller size than what the machine is designed for. I also tried setting the material size to the actual size of the available cutout area, with no success.

I did some reading online, and one person mentioned altering the gcode settings of S20, and S21. I believe i changed these to 0, and then the unit worked perfectly.

The problem now is that tge unit wants to go outside of its limits when homing, and manually moving the arrow keys on laser grbl. What is wrong with my DXF file, which is causing this error?

[weldguy]

This is all out of my realm of knowledge but I am curious what S20 and S21 are?

[acourtjester]

the S20 and S21 have to to do with the soft and hard limits of the machine. You may be having a problem with the G-code if created in Metric and you are using English sizes. Sizing setting are needed in both LIghtburn and GRBL so they are in sync. If you are funning connected through Lightburn you may try the "Framing Function" to see if the G-code runs outside of the machine or the limits.
Attached is a sheet showing the setup setting for GRBL with the S names and values. many are setting of 0 or 1 for on of off.

Laser console $ number descriptions.odt

(22.78 KiB) Downloaded 14 times

[weldguy]

Thanks for the info Tom

[jeremy_smitty]

Will lasergrbl work if i set the gcode to inches, instead of millimeters?

All of my work is in imperial (inches). How do i go about syncing the engraver to be in inches?