RRF3.2 request to enable G43 & G44 Tool height offset

EducatingSavvas

@jay_s_uk Thanks for sharing that! There's a lot of food for my thoughts, and the touch probes look really good btw. My set up is a little different as I have a stationary button which acts as my tool touch probe. It is also set below the surface of my wasteboard at the front of my machine.

So this is not tested, but I imagine I could use:

M291 X1 Y1 Z1	; jog to wasteboard
G10 L2 P9 Z{move.axes[2].machinePosition}	; Save coordinate to G59.3 WC
M500			; Store to memory

I can then move to my probe location at the front of my machine:

M291 P"STAND CLEAR! Move to Probe Location." R"Warning" S3
G90			; absolute movement
G53 G0 Z-10; 		; move to safe Z in machine coordinate system
G53 G0 X83 Y41.7	; move X and Y second in machine coordinate system above stationary probe button

and then perform my probe cycle.

M291 P"Ensure tool is above stationary probe location." R"Warning" S3
G10 P8 X0 Y0 Z0	; reset axis tool offset
G30 S-1		; Probe at the current XY position and report 
G91		; incremental movement
G10 L8 P8 Z{move.axes[2].machinePosition}	; adjust G59.2 WCS
G10 L20 P1 Z{move.axes[2].workplaceOffsets[9]-move.axes[2].workplaceOffsets[8]} ; Set origin of G54 Z relative to the current position of the tool, minus wasteboard offset from tool probe offset???
M500			; store to memory
G53 G0 Z-10		; move to safe z position

Going to have to trail this out when I next have time. It didn't occur to me that I could save axis location to workspace coordinates but this is a great lead. And in theory I won't have to perform the first part until I resurface flat the wasteboard. I'll report back on the weekend once I have tested it. Cheers!

EducatingSavvas

@jay_s_uk I'm going to have to wait till I wire up the test rig onto my CNC machine to test this. It's too confusing to imagine the stages without seeing the machine moving. May take a while to report back.

Educating Savvas Duet CNC Test Rig .jpg

jay_s_uk

@EducatingSavvas don't worry, I won't be going anywhere

EducatingSavvas

@jay_s_uk Can I ask what firmware version you are using. I'm following your workflow but having to make random changes. I'm using RRF 3.2 beta 2.

jay_s_uk

I'm also running 3.2beta3.2

EducatingSavvas

I can confirm I've been able to create macros to set the wasteboard and tool length. My wasteboard setting macro is:

M291 P"Jog spindle until tool tip touches surface of waste board." R"Set Waste Board" S3 X1 Y1 Z1 ; jog to wasteboard
G10 L2 P9 Z{move.axes[2].machinePosition}		; save coordinate to G59.3 WC
G10 L2 P2 Z{move.axes[2].workplaceOffsets[8]} – {move.axes[2].workplaceOffsets[7]}	; Subtract G59.3 from G59.2 and set offset in G55
M400							; wait for last command to end
M500							; store to memory
G55							; swap to G55 WC

and stationary tool length setting macro:

G55				; return to G55 WC
G10 P1 X0 Y0 Z0			; reset axis tool offset
M291 P"Press Ok to peform probe cycle" R"Warning" S3
G30 S-1	K0			; begin probing movement
G91				; incremental movement
G1 F500 Z3			; move up 3mm
G90				; absolute movement
G30 S-1	K0 			; begin probing movement
M400						; wait for current move to finish
G10 L2 P8 Z{move.axes[2].machinePosition}		; store probe ocaiton to G59.2 P8 
G10 L2 P2 Z{move.axes[2].workplaceOffsets[8]} – {move.axes[2].workplaceOffsets[7]}	; Subtract G59.3 from G59.2
M500			; store to memory
G53 G0 Z-10		; move to safe z position

I use G54 to mirror the G53 machine position - so work in G55. I use G59.3 to set the wasteboard, and G59.2 for stationary touch probe. for set Thank @jay_s_uk for pointing me in the right direction.

tom33

@jay_s_uk Hi, thanks for sharing this macro. When you write "G10 L2 Z" which system coordinate will change the G53 ? Because there is no P parameters
Thanks,

jay_s_uk

@tom33 I don't use G53 in my probing macros. I've only used it in the context of tool changing. But, it uses the machine coordinates as a base (so from the machine 0,0 position) and not workplace coordinates

tom33

@jay_s_uk ok so like that there is no a G54/G55 for change the work coordinate system at the begining of a gcode ?

jay_s_uk

@tom33 I believe setting the system in CNC mode (M453) automatically puts the machine in G54

chiefmonkey

Guys this seems to be a great work around for the limitation on variables, as from what I can tell you are using the work offsets of non used coordinate systems to store the values from your probing, and then performing the math on them to get the result you desire.

The only syntax that I am having a hard time following is where do the "move.axes[].machinePosition" and "move.axes[].workplaceOffsets[]" come from. I assume they are calling something at the firmware level, but it seems documentation on this is limited.

I have seen other threads where people are using these meta commands, but finding documentation on them is rather limited. I've gone so far as to dig into linuxCNC as it appears some of this work is derived from there. Any suggestions on where to learn more on the meta command structure would be greatly appreciated.

Phaedrux

@chiefmonkey https://duet3d.dozuki.com/Wiki/GCode_Meta_Commands

Have you seen this? Actual variables are now available as well.

chiefmonkey

@phaedrux said in RRF3.2 request to enable G43 & G44 Tool height offset:

https://duet3d.dozuki.com/Wiki/GCode_Meta_Commands

I have seen that, we are a bunch of mechanical oriented guys in our group, so programming is taking us quite a while, so much different then C that I used to use.