Tool Change: Moving in axis without calling them

Danal · 16 Nov 2019, 17:13

This can be fixed two ways:

Make every move in 'tpre' macros have a g53.
Do very little in 'tpre' and do the actual mount and position of the tool in 'tpost'. During 'tpost', tool offsets will be active.

There is no right or wrong between these two... still I personally prefer (2).

smoki3 · 16 Nov 2019, 17:17

@Danal said in Tool Change: Moving in axis without calling them:

This can be fixed two ways:

Make every move in 'tpre' macros have a g53.

Do very little in 'tpre' and do the actual mount and position of the tool in 'tpost'. During 'tpost', tool offsets will be active.

There is no right or wrong between these two... still I personally prefer (2).

Yes this is the workaround that I am actually using. But it is not possible for the Z axis because in a print the Z height is variable.

But this a definitely a bug because in tpre.g tool offset is inactive so the should be no difference if I use a G53 or not. If you do a T-1 between the tool change you get a completely different behavior.

Danal · 16 Nov 2019, 17:18

Just for reference, here is a set of files that does minimal work in 'pre' and does most of the work in 'post'.

http://danalspub.com/wp-content/uploads/2019/11/Backup-Toolchange-Jubilee-Nov-16-19-0945.zip

Keep in mind these files are NOT "golden" in any way... they just work on my machine.

Oh, and they are designed to move the new tool to the same position the old tool had before the tool change. If you don't want this, just take out the three G1 (or G0) commands at the end of 'post' that have the "R2" in them.

smoki3 · 16 Nov 2019, 17:25

@Danal
Why do you expect a Y movement?

With the end of the tfree.g the tool offset is gone. So every move you do after this is in the global coordinate system, no matter it was before with the activated tool offset. And the tool offset of the new tool get activated after the tfree.g (before the tpost.g)
And if I place my toolhead G53 G1 Y165 then it have to stay there until it gets another Y axis command. (same for the Z and X axis)

smoki3 · 16 Nov 2019, 17:26

@Danal said in Tool Change: Moving in axis without calling them:

Just for reference, here is a set of files that does minimal work in 'pre' and does most of the work in 'post'.

http://danalspub.com/wp-content/uploads/2019/11/Backup-Toolchange-Jubilee-Nov-16-19-0945.zip

Keep in mind these files are NOT "golden" in any way... they just work on my machine.

Oh, and they are designed to move the new tool to the same position the old tool had before the tool change. If you don't want this, just take out the three G1 (or G0) commands at the end of 'post' that have the "R2" in them.

I know there are many workarounds but it does not change the fact that this behavior is normal

Danal · 16 Nov 2019, 17:35

I'd expect that move because that's my understanding of how g-code works, per the NIST standard.

The NIST spec defines the exact sequence of how coordinates are calculated for every move. "Running" that sequence of events for a G1 after a tool offset is removed WILL result in a move of an axis that is "no longer where it should be".

I could be wrong... but, given that the machine behaves the way the spec reads...

Danal · 16 Nov 2019, 17:45

Of course, now I'm sitting here issuing sequences of M114, G10, G1, etc, etc, and I can't reproduce what I'm theorizing... so I probably am wrong...

I'll keep looking.

smoki3 · 10 Dec 2019, 21:43

@dc42
I found a video on the e3d forum where you can see the issue:

https://youtu.be/5RXE5qRVJgI

At 0:33 you can see the tool change and the moving Z-axis.

Danal · 11 Dec 2019, 15:02

It seems likely to me that all the Z moves from between about :27 and :37 are coded into their pre/post/free macros. I have Z moves in mine, and they have to produce a good outcome no matter what the sequence of events. Therefore, moves occur during a regular single change that look a little weird. They are important when starting with no tool, or ending that way, or etc.

Danal · 11 Dec 2019, 15:03

And, I have not had time to research this any further. I will be getting back to my toolchanging printer soon, to work out the final kinks. I will report back when I know something more about this issue.

smoki3 · 13 Dec 2019, 11:22

@Danal
no they are not coded. Just the lift of the nozzle before the tool change starts. Anything else is due to the fact that there is an issue after the tfree.g script with calculating the position.

If you do a T-1 and then a T1 you get a different behaviour. Then you dont have the Z-movement even though are running exactly the same scripts.

When you go back to 2.02 there you see you dont have this movements.

smoki3 · 13 Dec 2019, 12:31

@smoki3 said in Tool Change: Moving in axis without calling them:

@Danal
no they are not coded. Just the lift of the nozzle before the tool change starts. Anything else is due to the fact that there is an issue after the tfree.g script with calculating the position.

If you do a T-1 and then a T1 you get a different behaviour. Then you dont have the Z-movement even though are running exactly the same scripts.

When you go back to 2.02 there you see you dont have this movements.

I found this comment in the GCodes.cpp, which sound a bit like this bug @dc42

else if (rp != nullptr)
			{
				currentUserPosition[axis] = moveArg + rp->moveCoords[axis];
				// When a restore point is being used (G1 R parameter) then we used to set any coordinates that were not mentioned to the restore point values.
				// But that causes issues for tool change on IDEX machines because we end up restoring the U axis when we shouldn't.
				// So we no longer do that, and the user must mention any axes that he wants restored e.g. G1 R2 X0 Y0.
			}

Danal · 13 Dec 2019, 14:01

@smoki3 said in Tool Change: Moving in axis without calling them:

and the user must mention any axes that he wants restored

Very interesting. I will keep that in mind as I research this further.

When you go back to 2.02 there you see you dont have this movements.

I can't run any version of 2; I am on Duet 3 hardware.

dc42 · 13 Dec 2019, 15:18

@smoki3 said in Tool Change: Moving in axis without calling them:

@smoki3 said in Tool Change: Moving in axis without calling them:

@Danal
no they are not coded. Just the lift of the nozzle before the tool change starts. Anything else is due to the fact that there is an issue after the tfree.g script with calculating the position.

If you do a T-1 and then a T1 you get a different behaviour. Then you dont have the Z-movement even though are running exactly the same scripts.

When you go back to 2.02 there you see you dont have this movements.

I found this comment in the GCodes.cpp, which sound a bit like this bug @dc42
else if (rp != nullptr)
			{
				currentUserPosition[axis] = moveArg + rp->moveCoords[axis];
				// When a restore point is being used (G1 R parameter) then we used to set any coordinates that were not mentioned to the restore point values.
				// But that causes issues for tool change on IDEX machines because we end up restoring the U axis when we shouldn't.
				// So we no longer do that, and the user must mention any axes that he wants restored e.g. G1 R2 X0 Y0.
			}

That change was introduced way back in firmware 1.19.

@Danal said in Tool Change: Moving in axis without calling them:

@smoki3 said in Tool Change: Moving in axis without calling them:

and the user must mention any axes that he wants restored

Very interesting. I will keep that in mind as I research this further.

When you go back to 2.02 there you see you dont have this movements.

I can't run any version of 2; I am on Duet 3 hardware.

I think the change in behaviour must be connected with this change, in the upgrade notes for 2.03:

Tool changers, IDEX printers and similar using tfree#.g and tpost#.g files: tool offsets are now applied within the tfree#.g and tpost#.g macros (but not in the tpre#.g file because no tool is selected at that point).

Perhaps there is a G1 command in the tfree or tpost file that needs to be corrected for tool offset, or else a G53 prefix added?

smoki3 · 13 Dec 2019, 15:30

@dc42

No I don't think so!

I actually investigating:

So frist my config:

; Configuration file for Duet WiFi (firmware version 1.21)
; executed by the firmware on start-up
;
; generated by RepRapFirmware Configuration Tool on Wed Sep 19 2018 21:12:53 GMT+0200 (Mitteleuropäische Sommerzeit)

; General preferences
G90                                                ; Send absolute coordinates...
M83                                                ; ...but relative extruder moves

; Network
M550 PCoreXY                                   	   ; Set machine name
M552 S1                                        	   ; Enable network
M586 P0 S1                                         ; Enable HTTP
M586 P1 S0                                         ; Disable FTP
M586 P2 S0                                         ; Disable Telnet

; Drives
M584 X0 Y1 Z2 E3:4:5:6 U7                          		; Map Drives to Axis
M669 K1                                            		; Select CoreXY mode
M569 P0 S0                                         		; Drive 0 goes forwards
M569 P1 S0                                         		; Drive 1 goes forwards
M569 P2 S1                                         		; Drive 2 goes forwards
M569 P3 S0                                         		; Drive 3 goes forwards
M569 P4 S0                                         		; Drive 4 goes forwards
M569 P5 S0                                         		; Drive 5 goes forwards
M569 P6 S0                                         		; Drive 6 goes forwards
M569 P7 S0                                        		; Drive 7 goes forwards
M350 X16 Y16 Z16 E16:16:16:16 I1                   		; Configure microstepping with interpolation
M350 U8 I0					   		; Configure microstepping without interpolation
M92 X100 Y100 Z1600 U100 E460:460:460:460          		; Set steps per mm
M566 X600 Y600 Z18 U2 E100:100:100:100         		   		; Set maximum instantaneous speed changes (mm/min)
M203 X35000 Y35000 Z1200 U25000 E5000:5000:5000:5000    	; Set maximum speeds (mm/min)
M201 X6000 Y6000 Z400 U500 E2500:2500:2500:2500         	; Set accelerations (mm/s^2)
M906 X1650 Y1650 Z1100 U200 E1450:1450:1450:1450 I30    	; Set motor currents (mA) and motor idle factor in per cent
M84 S120                                           		; Set idle timeout

; Axis Limits
M208 X-13.5 Y-56 Z0 U0 S1                          		; Set axis minima
M208 X316 Y202 Z270.20 U500 S0                     		; Set axis maxima

; Thermal Sensors
M308 S0 P"bedtemp" Y"thermistor" T100000 B3950                   	; Set thermistor + ADC parameters for heater 0
M308 S1 P"e0temp" Y"thermistor" T100000 B4725 C7.060000e-8       	; Set thermistor + ADC parameters for heater 1
M308 S2 P"e1temp" Y"thermistor" T100000 B4725 C7.060000e-8       	; Set thermistor + ADC parameters for heater 2
M308 S3 P"e2temp" Y"thermistor" T100000 B4725 C7.060000e-8      	; Set thermistor + ADC parameters for heater 3
M308 S4 P"e3temp" Y"thermistor" T100000 B4725 C7.060000e-8      	; Set thermistor + ADC parameters for heater 4

; Hardware
M950 H0 C"bedheat" T0
M950 H1 C"e0heat" T1
M950 H2 C"e1heat" T2
M950 H3 C"!exp.heater3" T3
M950 H4 C"!exp.heater4" T4
M950 F3 C"duex.fan3"
M950 F4 C"duex.fan4"
M950 F5 C"duex.fan5"
M950 F6 C"duex.fan6"
M950 F7 C"duex.fan7"
M950 F8 C"duex.fan8"

; Max Temp Protection
M143 H0 S140                                   ; Set temperature limit for heater 0 to 140C
M143 H1 S270                                   ; Set temperature limit for heater 1 to 270C
M143 H2 S270                                   ; Set temperature limit for heater 2 to 270C
M143 H3 S270                                   ; Set temperature limit for heater 3 to 270C
M143 H4 S270                                   ; Set temperature limit for heater 4 to 270C

; Fanmapping
M106 P0 S0 I0 F500 H-1 C"Tool 0"               ; Set fan 0 value, PWM signal inversion and frequency. Thermostatic control is turned off
M106 P3 S0 I0 F500 H-1 C"Tool 1"               ; Set fan 3 value, PWM signal inversion and frequency. Thermostatic control is turned off
M106 P7 S0 I0 F500 H-1 C"Tool 2"               ; Set fan 7 value, PWM signal inversion and frequency. Thermostatic control is turned off
M106 P5 S0 I0 F500 H-1 C"Tool 3"               ; Set fan 5 value, PWM signal inversion and frequency. Thermostatic control is turned off
M106 P1 S1 I0 F500 H1 T55                      ; Set fan 1 value for Tool 0, PWM signal inversion and frequency. Thermostatic control is turned on
M106 P4 S1 I0 F500 H2 T55                      ; Set fan 2 value for Tool 1, PWM signal inversion and frequency. Thermostatic control is turned on
M106 P6 S1 I0 F500 H3 T55                      ; Set fan 6 value for Tool 2, PWM signal inversion and frequency. Thermostatic control is turned on
M106 P8 S1 I0 F500 H4 T55                      ; Set fan 8 value for Tool 4, PWM signal inversion and frequency. Thermostatic control is turned on

; Endstops
M915 X Y S5 H350 F0 R0           	       ; Set Stall detection sensitivity
M915 U S5 H200 F0 R0			       ; Coupler
M574 Y1 S3                                     ; Set endstops controlled by motor load detection
M574 X1 S3                                     ; Set endstops controlled by motor load detection
M574 U0                                        ; Set endstops controlled by motor load detection

; Z-Probe
M574 Z0 C"nil" 		                       ; no Z endstop switch, free up Z endstop input
M558 P5 C"!zstop" H3 F180 T25000	       ; Z probe connected to Z endstop input
G31 X0 Y0 Z0.00 P500          	               ; Set Z probe offset + naher ran - weiter weg
M557 X5:295 Y0:190 S48.33:47.5                 ; Define mesh grid

; Tools
M563 P0 D0 H1 F0                               ; Define tool 0, Fan 0
M563 P1 D1 H2 F3                               ; Define tool 1, Fan 3
M563 P2 D2 H3 F7                               ; Define tool 2, Fan 7
M563 P3 D3 H4 F5                               ; Define tool 3, Fan 5

; PID Settings Tools
M307 H1 A595.9 C199.5 D4.5 S1.00 V24.1 B0      ; Set PID settings tool 0
M307 H2 A775.0 C252.4 D8.2 S1.00 V24.1 B0      ; Set PID settings tool 1
M307 H3 A716.5 C237.1 D8.7 S1.00 V24.1 B0      ; Set PID settings tool 2
M307 H4 A567.7 C241.0 D6.7 S0.80 V24.1 B0      ; Set PID settings tool 3
M307 H0 A181.4 C631.5 D4.9 S1.00 V24.1 B0      ; Bed PID Settings

; Tooloffset
;G10 P0 X0.00 Y34.50 Z-15.84                    ; Set tool 0 axis offsets
;G10 P1 X0.55 Y34.50 Z-15.83                    ; Set tool 1 axis offsets
;G10 P2 X0.16 Y34.50 Z-15.85                    ; Set tool 2 axis offsets
;G10 P3 X0.25 Y34.50 Z-15.70                    ; Set tool 3 axis offsets
M98 Ptooloffset.g

; Tools Temperatures
G10 P0 R0 S0                                   ; Set initial tool 0 active and standby temperatures to 0C
G10 P1 R0 S0                                   ; Set initial tool 1 active and standby temperatures to 0C
G10 P2 R0 S0                                   ; Set initial tool 2 active and standby temperatures to 0C
G10 P3 R0 S0                                   ; Set initial tool 3 active and standby temperatures to 0C

; LED Strip
M950 F2 C"nil"				       ; Free fan 2 pin
M950 P2 C"fan2"				       ; create GPIO pin 2 attached to fan 2
M42 P2 S30				       ; Turn LEDs on 30% PWM

; Calibrate MCU Temperature
M912 P0 S-8

; DAA
M593 F80

; Load config override
M501

Then I created a simple tpre.g (same for T0 and T1, just X0 for T0 and X50 for T1):

; tpre0.g
; called before tool 0 is selected


G1 X0 F5000
M400
M98 P"/macros/Toolhead/1. Toolhead unlock"
G4 P400

G1 Y110 F5000
M400

M98 P"/macros/Toolhead/2. Toolhead lock"
G4 P260

G1 Y100 F5000

Then the tfree.g (same X0 for T0 and X1 for T1):

; tfree0.g
; called when tool 0 is freed

G91
G1 Z10 F7200
G90


G53 G1 X0 F5000 ;XPOS
G53 G1 Y110
M400
M98 P"/macros/Toolhead/1. Toolhead unlock"
G4 P320
G53 G1 Y100 F5000
M400

tpost.g is completely empty for both.

the tool offsets are defines as followed:

; Tooloffset
G10 P0 X20.00 Y15 Z-12.0                    ; Set tool 0 axis offsets
G10 P1 X20.00 Y15 Z-12.0                   ; Set tool 1 axis offsets

smoki3 · 13 Dec 2019, 15:37

@dc42

I made some videos:

First I have just clicked on T0 to pick it up:

https://photos.app.goo.gl/ipCKj1bHJ15dw8NKA

After this I picked up T1 by clicking on it in DWC:

https://photos.app.goo.gl/yqMHUWQt5n7gYiPX6

Last on I deactivated T1 by click again on T1 in DWC:

https://photos.app.goo.gl/Nnn5NxX9C4Ph9WFx5

So do you see this wired diagonal move with XY axis and Z Axis in the second video?

Danal · 13 Dec 2019, 17:17

I understand why offsets are/aren't applied. They correlate to the "what tool number is currently mounted" status of the printer.

Therefore, I have G53 in front of the vast majority of the moves, because those moves need to deal with the parking posts in absolute terms.

I'll see if I can reproduce what happens in the above vids.

smoki3 · 13 Dec 2019, 17:29

@Danal said in Tool Change: Moving in axis without calling them:

I understand why offsets are/aren't applied. They correlate to the "what tool number is currently mounted" status of the printer.

Therefore, I have G53 in front of the vast majority of the moves, because those moves need to deal with the parking posts in absolute terms.

I'll see if I can reproduce what happens in the above vids.

As you can see in my tpre script I also have G53 in front of every move. That this diagonal move does not exist in the script and only happens if you directly move from T0 to T1 if you do a T0 → T-1 → T1 it does not happen.

But I am not able to see at which coordinates. this diagonal move ends

smoki3 · 13 Dec 2019, 17:55

So I adjusted the tool offset not to this:

; Tooloffset
G10 P0 X0.00 Y50 Z0.0                    ; Set tool 0 axis offsets
G10 P1 X0.00 Y0 Z0.0                   ; Set tool 1 axis offsets

Then it looks like this:

https://photos.app.goo.gl/MzJ7iRV5FMb3namx7

As you can see the printer is moving diagonal 50mm in X axis (from the tpre.g) and Y axis (from removing the tool offset). The Z movement is gone because there is not Z tool offset defined.

Normaly it should just release T0 and move just 50mm in X axis as defined in the tpre script.

dc42 · 15 Dec 2019, 14:49

Please try the firmware at https://www.dropbox.com/sh/3azy1njy3ayjsbp/AACquxr2m00eV568RZg5QG5wa?dl=0. Running the Duet 2 version of this firmware on my tool changer, I don't see any diagonal moves, where as I did when running RRF 2.

Note, currently you cannot downgrade from this firmware via Duet Web Control when running with an attached SBC. That will be fixed shortly. Meanwhile, you can downgrade by running in standalone mode or by using Bossa.