INITIAL HOMING BLUES

swrightlast

; homey.g
; called to home the Y axis
;
; generated by RepRapFirmware Configuration Tool v2 on Sun Aug 25 2019 14:27:06 GMT-0700 (Pacific Daylight Time)
G91 ; relative positioning
G1 Z5 F6000 S2 ; lift Z relative to current position
G1 S1 Y-305 F1800 ; move quickly to Y axis endstop and stop there (first pass)
G1 Y5 F6000 ; go back a few mm
G1 S1 Y-305 F360 ; move slowly to Y axis endstop once more (second pass)
G1 Z-5 F6000 S2 ; lower Z again
G90 ; absolute positioning

@swrightlast ; homez.g
; called to home the Z axis
;
; generated by RepRapFirmware Configuration Tool v2 on Sun Aug 25 2019 14:27:07 GMT-0700 (Pacific Daylight Time)
G91 ; relative positioning
G1 Z5 F6000 S2 ; lift Z relative to current position
G90 ; absolute positioning
G1 X15 Y15 F6000 ; go to first probe point
G30 ; home Z by probing the bed

; Uncomment the following lines to lift Z after probing
;G91 ; relative positioning
;G1 S2 Z5 F100 ; lift Z relative to current position
;G90 ; absolute positioning

Phaedrux

@swrightlast said in INITIAL HOMING BLUES:

I said home right rear, 0,0 because thats what my gridded bed shows, with front right, 0,300, and front left 300, 300.

This orientation can be maintained if you wish. Just note that parts printed will be rotated 180 degrees from the preview in the slicer. Provided of course that we get the rest of the config setup.

Were you able to perform this test yet?

For a CoreXY or H-Bot machine, RepRapFirmware assumes that the motor connected to the X motor output moves the head in the +X and +Y directions when it runs forwards, and that the Y motor moves the head in +X and -Y directions when it runs forwards. [Note: firmware 1.18 and earlier assumes that the motor connected to the Y motor output moves the head in the -X and +Y directions when it runs forwards].

So you can start with these M569 commands in config.g:

M569 P0 S0 ; X motor runs forwards
M569 P1 S0 ; Y motor runs forwards
Then test for the correct X motor movement by sending these commands from the console:

G91
G1 S2 X10 F3000

If the head moves diagonally in the +X and +Y directions, all is well. If it moves in the -X and -Y directions, change the S parameter to S1 in the M569 P0 command. If it moves towards +X and -Y, or towards -X and +Y, turn the power off and swap the X and Y motor connections.

When you have the X motor moving correctly, test the Y motor by sending from the console:

G91
G1 S2 Y10 F3000

For firmware 1.19 and later: If the head moves diagonally in the +X and -Y directions, all is well. If it moves in the -X and +Y directions, change the S parameter in the M569 P1 command to S1.

Important: make sure that you have chosen a right-hand axis system. That is, looking down on the printer the +Y direction should be 90 degrees anticlockwise from the +X direction. If instead it is 90 degrees clockwise, you have a left-hand axis system, which will give you mirror-image prints.

Phaedrux

@swrightlast said in INITIAL HOMING BLUES:

M574 X1 Y1 Z0 S0 ; set active low endstops

So this says that you have the endstops on the low end, which according to your bed decals is correct. And you use active low endstop switches.

If you wanted to change this to a right hand coordinate system with 0,0 in the front left, you'd need to change it to be M574 X2 Y2 Z0 S0 which tells it that the switches are located at the high end of travel.

G1 S1 X-305 F1800 ; move quickly to X axis endstop and stop there (first pass)
G1 X5 F6000 ; go back a few mm
G1 S1 X-305 F360 ; move slowly to X axis endstop once more (second pass)

This is correct movement direction for low end endstop position. Same for your homey commands.

If you wanted to change to a right hand coordinate system, the directions of the movements would have to be reversed. Ex:

G1 S1 X305
G1 X-5
G1 S1 X305

So this leaves just my previous question about testing for correct motor direction movement. The test as described above assumes a right hand coordinate system. So I'm interested to see what you report.

When you tell it to home X, which direction does the print head move? It should be moving to the right as it's currently configured.

swrightlast

@Phaedrux When homing x, it moves toward the front in the y direction.

Phaedrux

Please do the motor direction test I posted above.