New "machine home" gcode

VcarvePro with UGS. Trying to set new machine home to bottom left of my spoil board so i don’t have to jog so far every start. I read in the forum that you can enter g28.1 in the command bar and it will set that as your new machine home, but it’s not. Another code maybe?

G28 is not a new machine home. It is a reference point which you can move to/from.

That is how I understand it.

As a hack you could move the limit switches, if you have them, and have the machine find 0,0,0 closer to wherever you want to start out.

When I use $H in UGS, my machine goes to 0,0,0 which is the bottom left of my machine. Is that what you’re trying to do?

It goes to 0,0,0 just fine using $h. Then, when I go to find datum of work piece, the first move the machine makes is halfway across the x axis. Then I have to jog all the back near the 0,0,0. Trying to get it close to the 0,0,0

You have set reasonable values here, right?

If your first move is halfway across X that distance must come from somewhere…

Or have I missed something essential here? Wouldn’t be the first time… :smile:

Yes. From homing position as soon as I start to find my workpiece it goes to the middle like I said with the first click. Then the rest of movements are prob 1 mm at a time(unless I increase the value).

What are the steps that you use to find your workpiece?

First thing you should do in UGS is set your units to the proper value either mm or inch.

Then $H (do you enter the command or press the $H button in UGS?) to home the machine. Then what do you do next?

I manually enter the $h command. switch tabs, first click of x,y or z moves it 10-15 inches to right. Following clicks are about 1mm steps


What is the G code information that prints out in the console window for the first click on x,y, or z after the homing sequence?

It is G0 X1 Y0 Z0

This is very strange. I’m really curious as to what is going on with your machine.

Can you post the $$ output from grbl here?

Well, that all looks good.

Try this:
Home the machine with command $H
Issue this command string and see what your machine does G21 G91 G0 X1 Y0 Z0

It just moves 1 step to the right

What this line of G code does is set the units to mm (G21) and positioning to relative (G91) and then fast move 1 mm in the X direction.

That’s what should be happening if you use UGS to home the machine and then click the X+ button.

For some reason your machine seems to be in an odd state when you home it and then press one of the movement buttons. The really bizarre part is that it seems to self correct on the next press.

I’m not sure what to suggest to correct the problem. Things you might try are re-flashing grbl into the Arduino, make sure that your Java runtime is current, maybe re-install UGS.

I think you’re right on two of those. need to update my Java and someone suggested looking into the nightly builds if UGS for another problem I was asking about. I appreciate you time Larry. My machine is carving fine and I’m learning everyday so I’m happy about that.