Version of G10 to set offset to current position?

DocTrucker · 16 May 2018, 07:34

Hi All,

I currently set the nozzle height by driving the nozzle down until it grabs a piece of paper and then set the G10 P0 Z[-1 * current z position].

Is there a way to use the current position to set the offset? Something where you drive the tool to a position and tell it what coordinate the machine should consider the current location as.

So currently an example would work flow would be:

Home all
Run three screw bed level correction
Run bed mesh probe
Drive nozzle down to grab the piece of paper at x=0, y=0.
[For this example it happened at z=-15.5]
Send "G10 P0 Z15.5

I can't set up a macro for this as it uses the current z position which is variable.

So perhaps the following could be considered?

Home all
Run three screw bed level correction
Run bed mesh probe
Drive nozzle down to grab the piece of paper at x=0, y=0.
[For this example it happened at z=-15.5]
Send "Gxx P0 X0 Y0 Z0

So it behaves like G92, but only applies to the specific tool. Come to think of it perhaps correct an offset if you add a Px section to the G92 command?

Thanks.

dc42 · 16 May 2018, 08:47

You should be able to accomplish that by sending M558 P0 to select manual Z probing followed by G30 S-2.

DocTrucker · 16 May 2018, 08:49

Ah ok, thanks. Will it upset the bed compensation or bed levelling though?

dc42 · 16 May 2018, 08:51

G30 S-2 changes only the Z offset of the current tool. You will need to set the correct Z probe type in M558 again after running this procedure.

DocTrucker · 16 May 2018, 08:54

Thanks for the information. I'll try this at home later this week.