Can't use positioning functions - and I'd really like to :)

[GJM (Gary Morgen)]

I’m sure this is simplistic and basic - and maybe answered before.

I have a Shapeoko CNC that’s fitted with a JTech Laser.
Upon starting LB, it initializes and homes (Back Right)
I run the Use Laser Macro

At this point, I can jog the laser, and run jobs successfully by moving the laser to the origin and using Start From current position. This works and I’m fine with it. However, I’d actually like to be able to use more of the positioning functions (like Get Position, Move to Position, Save Position, etc.). However, whenever I use any of these functions, the gantry takes off towards the bottom left and (since I don’t have any limit switches on that side of the CNC) bangs against the limits of the machine if I don’t stop it.

I use the CNC primarily for CNC-ing and less often for the laser, but I’d really like to be able to use both fully.

What do I have to do to be able to Get a Position and the Go back to that position and use the other functions?

[jkwilborn (Jack Wilborn)]

How are you manually homing the machine?

The ‘home’ on the machine needs to have the same ‘home’ or origin as the software “Edit → Device Setup”. Also that you are in proper mm/min or mm/s

Only Move should cause an issue as far as causing any machine movement. Probably have to make ‘Start from’ absolute coordinates.

[GJM (Gary Morgen)]

Hi Jack. Since a couple of releases ago, my machine started homing automatically when LB starts up. I’m not manually homing it. It’s going to the back right corner and initializing on startup. As for my units, I’m in inches and I believe I’m set correctly, because my jobs are working and jogging is not an issue.

I’m going to bet my entire problem is that the Origin got set back to front left on the settings screen. I know I changed it to back right before, but, for whatever reason, it seems to have reverted. I’ll have to check it on my machine in the shop tomorrow to be sure.

Move is working just fine with my current setup - and, as I mentioned, I’ve been successfully burning lots of projects over the past year and a half, just putting the laser on my origin manually and starting from current location. But I can do a lot better.

I’ll check the origin setting on my shop machine tomorrow.

Thanks for pointing it out (and reminding me)…

• Gary

[jkwilborn (Jack Wilborn)]

I think there is an option for to home on startup of Lightburn.

Most machines home when you power them up or reset them. Otherwise they don’t know where they are…

On power up you should be able to get the current position in the move window. If it’s 0, 0 that’s great. Some do use negative coordinates, but none of my machines do, so I not the one to answer that question.

If it’s not retrieving the data, maybe you have the wrong grbl device or the status register ($10…?) is not set correctly.

Did you try the ‘set laser position’ to see if that works properly…?

Good luck…