More details on G30 - Single Z-Probe

According to the Marlin docs the G30 command's description is "Do a single Z probe at a specified position. By default probe in the current position."

Is G30 the alternative to G29 (auto bed levelling).

I want to convert my Prusa clone to a light CNC machine and am thinking of probing for the thickness of the material at the start of the job to have a repeatable 0 (zero ) start.

This does however mean that I will need to make the probe a stow-away probe on a servo but I am good with that.

Does G30 perhaps reset Z to a new zero height when done after the homing was done? I could then, in my gcode, home first as usual, then go and pause at some high-ish Z height while I fasten my material to the bed. Then I can do a Z-probe on the material for thickness when I click continue.

Normally a CNC mill probes Z through shorting the endstop to a block of metal with a known thickness. What kind of probe will you use? Also, what kind of material will you mill?

Did you check the CNC options in advanced configuration of Marlin?

In smoothieware it says:
G30 G-code
G30 means “move the probe until it hits something in the Z axis”.

On CNC mills it can be used to :

Find where the workpiece is located in the Z dimension
Find the length of a newly inserted tool
Find the touch point between a tool and the workpiece

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http://www.marinusdebeer.nl/

Quote
Ohmarinus
Normally a CNC mill probes Z through shorting the endstop to a block of metal with a known thickness. What kind of probe will you use? Also, what kind of material will you mill?

Did you check the CNC options in advanced configuration of Marlin?

In smoothieware it says:
G30 G-code
G30 means “move the probe until it hits something in the Z axis”.

On CNC mills it can be used to :

Find where the workpiece is located in the Z dimension
Find the length of a newly inserted tool
Find the touch point between a tool and the workpiece

Thanks for the response.

I want to "Find where the workpiece is located in the Z dimension" so yes I want to move the probe until it hits something in the Z axis

I want to get little endmills and drills that have the little "collar" on the so that i will always have a known bit/tool length

What materials: PC boards, perspex and soft woods.

What probe: probably just a normal micro-switch (the type with the arm and little wheel)

I have had a look at the advanced configuration yes but have not gone into great detail just yet.

Quote
JacquesBlom

Quote
Ohmarinus
Normally a CNC mill probes Z through shorting the endstop to a block of metal with a known thickness. What kind of probe will you use? Also, what kind of material will you mill?

Did you check the CNC options in advanced configuration of Marlin?

In smoothieware it says:
G30 G-code
G30 means “move the probe until it hits something in the Z axis”.

On CNC mills it can be used to :

Find where the workpiece is located in the Z dimension
Find the length of a newly inserted tool
Find the touch point between a tool and the workpiece

Thanks for the response.

I want to "Find where the workpiece is located in the Z dimension" so yes I want to move the probe until it hits something in the Z axis

I want to get little endmills and drills that have the little "collar" on the so that i will always have a known bit/tool length

What materials: PC boards, perspex and soft woods.

What probe: probably just a normal micro-switch (the type with the arm and little wheel)

I have had a look at the advanced configuration yes but have not gone into great detail just yet.

I think G30 really is your only choice, the only fear I'm having is that you have to let the probing start above the item you're trying to probe. So best first home the X and Y axis with 'G28 X Y' this will probably leave out the Z axis from the homing sequence. After this you might be able to manually raise Z and then position it above the workpiece by using the machine controls (do not do this manually as it will lose the homing coordinates). After that perform G30.

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http://www.marinusdebeer.nl/