The back off might not be proper in relative position.

fcwilt

Typically the homing procedure involves 3 relative moves.

1st - "fast" toward the endstop sensor until it is triggered.
2nd - back off a short distance - often at the same speed.
3rd - "slow" toward the endstop sensor until it is triggered.

You are switching to absolute for move 2 - why are you doing that?

Your 4th move for each axis has no F parameter and is going to be done at F25 which is quite slow - is that what you want?

Thanks.

Frederick

mendelevium

@siam
The exact script is this;-

mendelevium
mendelevium
6 Jun 2021, 12:15

Error: Bad command: this home all script has to be rethought when the printer is commissioned. The back off might not be proper in relative position.

mendelevium

@fcwilt
That is exactly what I am doing. when I hit the end-stop a second time slowly - to be more precise.
then I back off away from the microswitch. The second back-off speed makes any difference? I decided to use absolute since the position is then accurate. I do not know if it makes a difference. At work I deal with a number of CNC machine tools- lathes, machining centers and others.. that is how they behave.

fcwilt

@mendelevium said in The back off might not be proper in relative position.:

@fcwilt
That is exactly what I am doing. when I hit the end-stop a second time slowly - to be more precise.
then I back off away from the microswitch. The second back-off speed makes any difference? I decided to use absolute since the position is then accurate. I do not know if it makes a difference. At work I deal with a number of CNC machine tools- lathes, machining centers and others.. that is how they behave.

Well as I said "typically" all three moves are relative.

And you are getting an error message mentioning "back off" and "relative".

If it were me I would just make all three moves relative and see if that makes the error message go away.

There is no advantage to having the 2nd move be absolute and it complicates the code a bit.

The speed of each move is up to you. It's fine to use the same speed for both the 1st and 2nd moves but, as you have done, the 3rd move is typically at a slower speed.

But you likely want the 4th move to be at a speed faster then F25.

dc42

@mendelevium said in The back off might not be proper in relative position.:

Error: Bad command: this home all script has to be rethought when the printer is commissioned. The back off might not be proper in relative position.

That message must be either in your homeall.g file or in homex.g, homey.g and homez.g. It is not generated by the firmware

mendelevium

@dc42
you mean the error is being generated by an improperly scripted homeall/homex/y/z right?
the homeall has all the three files scripts in it.

mendelevium

@fcwilt
nothing to loose by trying your suggestion...

dc42

@mendelevium said in The back off might not be proper in relative position.:

@dc42
you mean the error is being generated by an improperly scripted homeall/homex/y/z right?
the homeall has all the three files scripts in it.

Yes. Please post the entire homeall.g file exactly as it is, also homex.g, homey.g, homez.g. Most likely, someone put those messages in the file(s) but they are not preceded by ';' so they are treated as commands instead of comments.

mendelevium

@dc42
Hmmm
the homeall has that. But funnily enough it is appears 6 times....

this home all script has to be rethought when the printer is commissioned. The back off might not be proper in relative position.

G91 ;relative mode
G1 Z275 F2000 H1 ; move Z rapidly / 300mm up/ until Homing is triggered
G90 ;absolute mode
G1 Z260 F100 ; retract z 3mm slowly
G91 ;relative mode
G1 Z5 F25 H1 ; re-home at slow speed
G90 ; return to absolute mode
G1 Z261 ; back off

G91 ;relative mode
G1 Y400 F1000 H1 ; move Y rapidly / 300mm up/ until Homing is triggered
G90 ; return to absolute mode
G1 Y299 F100 ; retract Y 3mm slowly
G91 ;relative mode
G1 Y10 F25 H1 ; re-home at slow speed
G90 ; return to absolute mode
G1 Y300 ; back off reference at absolute

G91 ;relative mode
G1 X500 F1000 H1 ; move X rapidly / 300mm up/ until Homing is triggered
G90 ; return to absolute mode
G1 X344 F100 ; retract X 3mm slowly
G91 ;relative mode
G1 X10 F25 H1 ; re-home at slow speed
G90 ; return to absolute mode
G1 X344 ; back off reference at absolute

; homez.g
; called to home the Z axis
; Created by Tonio 28feb 2021
G91 ;relative mode
G1 Z275 F2000 H1 ; move Z rapidly / 300mm up/ until Homing is triggered
G90 ;absolute mode
G1 Z260 F100 ; retract z 3mm slowly
G91 ;relative mode
G1 Z5 F25 H1 ; re-home at slow speed
G90 ; return to absolute mode
G1 Z261 ; back off

; homey.g
; called to home the Y axis
;
; Created by Tonio 28feb 2021
G91 ;relative mode
G1 Y400 F1000 H1 ; move Y rapidly / 300mm up/ until Homing is triggered
G90 ; return to absolute mode
G1 Y299 F100 ; retract Y 3mm slowly
G91 ;relative mode
G1 Y10 F25 H1 ; re-home at slow speed
G90 ; return to absolute mode
G1 Y300 ; back off reference at absolute

; homex.g
; called to home the X axis
;
; Created by Tonio 28feb 2021
G91 ;relative mode
G1 X500 F1000 H1 ; move X rapidly / 300mm up/ until Homing is triggered
G90 ; return to absolute mode
G1 X344 F100 ; retract X 3mm slowly
G91 ;relative mode
G1 X10 F25 H1 ; re-home at slow speed
G90 ; return to absolute mode
G1 X344 ; back off reference at absolute

mendelevium

@dc42
took off that comment and the error vanished... thanks so much
the matter is closed..