Me too
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ive also heard good things about linux cnc but iâm new to machining so baby steps i suppose.
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This seems to be an old thread but just in case someone else finds this usefull. Use g28.1 to store the toolchange position then g28 to go to that position for tool change. I usually make my g28.1 the same as my work zero but my Z 30mm higher.
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Can you please explain this better?
Well, you go to a position, somewhere where you can easily access the endmill and it clears the workpiece. You send the gcode G28.1 and that stores that position. Then when you want to do a tool change, just send G28, and it will go back to that spot. This way you dont need to rehome when you change tools. All you have to do is redo the Z axis home.
Not really, i dont have homing enabled.
g28 and g30 are just coordinate offsets. It really doesnât mater if you have homing or not. If you dont have homing, you move your spindle to a position you like and zero out your g30 and g28. The only difference with using homing is that those offsets will always be âconstantâ.
I think @PhilJohnsonâs description on this one is better, and Iâd add that you always have a kind of homing - it just might not be the homing you expect.
When grbl starts up, the current position of the spindle is special; itâs one of the corners of an virtual box thatâs called machine coordinates. Normally, grbl expects you to have homing switches and youâre supposed to run the $H macro after power-up. You can see in the code that $H is really special - take a look here.
Youâre right that you can just use G28 coordinates for a lot of things, but personally my life got a lot easier when I actually started using the homing switches. Especially when using Fusion 360, everything just assumes that you have machine coordinates set up correctly.
FYI, if you really are interested in how things work in grbl, I think the code is probably readable even if youâve never tried to read C before. Give it a shot!
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