RepRap Firmware M666

Am I correct in assuming that positive numbers move the position closer to the end stop and negative numbers closer to the bed?

Assuming a delta with an X offset of -1.0mm -0.9 would be 0.1 closer to end stop and -1.1 0.1 closer to the bed or do I have it backwards?

Increasing all the endstop adjustments by 1mm is equivalent to increasing the homed height (M665 H parameter) by 1mm. That would put the head 1mm lower. So a positive endstop adjustment moves the head closer to the bed.

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Large delta printer [miscsolutions.wordpress.com], E3D tool changer, Robotdigg SCARA printer, Crane Quad and Ormerod

Disclosure: I design Duet electronics and work on RepRapFirmware, [duet3d.com].

Thanks. I need to tweak my setup a bit because I'm not getting a good first layer in front of X and Z towers and just a bit squished in front of the Y tower.

My plan is to adjust everything down by 0.1mm and then raise the Y up 0.1 or 0.15mm from the bed.

If you are using a Z probe and auto calibration, then you are probably getting inconsistent Z probe trigger heights, usually due to the effector tilting as it translates. If you are trying to calibrate manually, try my delta calibration calculator at [escher3d.com].

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Large delta printer [miscsolutions.wordpress.com], E3D tool changer, Robotdigg SCARA printer, Crane Quad and Ormerod

Disclosure: I design Duet electronics and work on RepRapFirmware, [duet3d.com].

Based on some reading in the forums I followed this algorithm to determine the FSR offset per point.

; x-opposite
; Home All
G0 X86.60 Y50.00 Z3.00
; jog down to paper
G92 Z0.00
G0 Z5.00
G30 X86.60 Y50.00 S-1
; update z offset in bed.g

This gave me a bed.g as follows

M561 ; clear any bed transform, otherwise homing may be at the wrong height
G31 X0 Y0 ; don't want any probe offset for this
G28 ; home the printer

; bed.g file for RepRapFirmware
; 7 points, 4 factors, probing radius: 110, probe offset (0, 0)
G28

; x-opposite
G30 P0 X86.60 Y50.00 Z-99999 H-0.29
; y-opposite
G30 P1 X-86.60 Y50.00 Z-99999 H-0.46
; z-opposite
G30 P2 X0.00 Y-110.00 Z-99999 H-0.14

; x-tower
G30 P3 X-56.29 Y-32.50 Z-99999 H-0.38
; y-tower
G30 P4 X56.29 Y-32.50 Z-99999 H-0.16
; z-tower
G30 P5 X0.00 Y65.00 Z-99999 H-0.39

; center
G30 P6 X0.00 Y0.00 Z-99999 H-0.22 S4

; get the head out of the way when done
G0 X0 Y0 Z50 F4000


So yes as you expected the FSR's are reading at different pressures depending on the points probed.

I removed my BuildTak and tied again with just the glass. It looks more consistent to me.

; x-opposite
G30 P0 X86.60 Y50.00 Z-99999 H-0.34
; y-opposite
G30 P1 X-86.60 Y50.00 Z-99999 H-0.47
; z-opposite
G30 P2 X0.00 Y-110.00 Z-99999 H-0.38

; x-tower
G30 P3 X-56.29 Y-32.50 Z-99999 H-0.43
; y-tower
G30 P4 X56.29 Y-32.50 Z-99999 H-0.29
; z-tower
G30 P5 X0.00 Y65.00 Z-99999 H-0.39

; center
G30 P6 X0.00 Y0.00 Z-99999 H-0.26 S4