Duet2+Duex5 3.4beta5: exploding leadscrews.
H2B last edited by H2B
Oddest occurrence today: after completing a print successfully on my Jubilee toolchanger, I removed the print as usual, and then clicked the "Print Again" option on DWC. Lo and behold, my G28 ran the Y and then X homing sequence, and then started the Z homing sequence.
The carriage failed to move to the center of the bed, as defined in my homez.g, and as such, the bed kept raising and seeking the endstop (conveniently located nowhere near where its supposed to be) until the anti-backlash nuts popped right off. I did get a single message stating "Error: G1/G2/G3: intermediate position outside machine limits" but I'm unsure when in the cycle this appeared.
Picture for posterity's sake:
Machine had no tools loaded (I had just completed a print), and here's the relevant sections of my gcode file in the start and end portions that would be relevant to what the machine was trying to operate.
Only thing that I think could have happened is somehow my homeu.g failed to complete, but in that case, why didn't the machine move in X or Y, but continued to move in Z?
I can easily add some conditional gcode to handle checking if axes are homed, but I really think this might be some overlooked area of the codebase that triggered this odd (and potentially machine-destroying) condition..
Start of gcode file:
M104 S235 T2 ; set temperature ;TYPE:Custom ; babystepping (PLA 0.11; PETG -0.03) M290 S-0.01 R0 M190 S55 R55 T0 P0 T1 P0 T2 P0 T-1 P0 ; BEGIN: start custom g-code G91 G1 Z5 ; drop bed slightly G90 ; absolute positioning G28 ; home all axes <---- this is where it failed. M558 F400 S0.01 G32 ; tram bed G32 G32 M558 F400 S0.01 G29
End of gcode file:
G1 X148.409 Y155.848 E-0.01371 ;WIPE_END G1 E-0.03 F3600 ; stop printing object cable_clinger_v0.stl id:0 copy 0 M107 ;TYPE:Custom ; Filament-specific end gcode ;END gcode for filament M104 S0 ; turn off temperature for tool T-1 ; unload tool ;G91 G1 Z10 G90 M0 ; call stop routine M84 ; disable motors
stop.g simply calls cancel.g, which is here:
; cancel.g ; called when a print is cancelled after a pause. T-1 ; park any active tool M400 G91 G1 Z5 G90 G0 X-20 Y-20 F42000 ; return all motions to home M140 S0 ; turn off the bed heater. M84 S600 ; disable motors after 10 mins of inactivity
; homeall.g ; called to home all axes X Y Z and Toolchanger lock ; G91 G1 Z5 F800 H2 ; Lift z so we don't crash M98 P"homey.g" M98 P"homex.g" M98 P"homeu.g" M98 P"homez.g"
; homey.g ; called to home the Y axis ; make sure everything has stopped before we make changes M400 ; Set relative mode G91 G1 Y-400 F6000 H1 ; Big negative move to search for endstop G1 Y4 F600 ; Back off the endstop G1 Y-10 F600 H1 ; Find endstop again slowly ; set absolute mode G90
; homex.g ; called to home the X axis ; M400 ; make sure everything has stopped before we make changes G91 ; Set relative mode G1 X-400 F6000 H1 ; Big negative move to search for endstop G1 X4 F600 ; Back off the endstop G1 X-10 F600 H1 ; Find endstop again slowly G90 ; Set absolute mode
homeu.g (toolchanger lock axis):
; Home U Axis G91 ; Set relative mode G1 U-100 F6000 H1 ; Big negative move to search for endstop G1 U6 F600 ; Back off the endstop G1 U-10 F600 H1 ; Find endstop again slowly G90 ; Set absolute mode
and finally, homez.g:
; Home Z Axis ; Set acceleration for travel moves M204 T10000 ; Lift z so we don't crash G91 G1 Z10 F800 H2 G90 ; Move to the center of the bed G1 X155 Y155 F42000 ; Set the probing speed M558 F500 ; run probe 1 G30 ; Set a slower probing speed M558 F100 ; run probe 2 G30
relevent entry from log file:
2021-11-02 20:20:31 [warn] Started printing file 0:/gcodes/cable_clinger_v0.gcode 2021-11-02 20:21:10 [warn] Leadscrew adjustments made: -0.072 -0.063 -0.030, points used 4, (mean, deviation) before (-0.056, 0.112) after (0.000, 0.111) 2021-11-02 20:21:29 [warn] Leadscrew adjustments made: -0.055 -0.051 -0.052, points used 4, (mean, deviation) before (-0.053, 0.114) after (0.000, 0.114) 2021-11-02 20:21:49 [warn] Leadscrew adjustments made: -0.052 -0.058 -0.056, points used 4, (mean, deviation) before (-0.056, 0.110) after (0.000, 0.110) 2021-11-02 20:23:12 [warn] 25 points probed, min error -0.155, max error 0.081, mean -0.017, deviation 0.060 Height map saved to file 0:/sys/heightmap.csv 2021-11-02 20:36:20 [warn] Finished printing file 0:/gcodes/cable_clinger_v0.gcode, print time was 0h 15m 2021-11-02 20:41:28 [warn] Started printing file 0:/gcodes/cable_clinger_v0.gcode 2021-11-02 20:41:50 [warn] Error: G1/G2/G3: intermediate position outside machine limits 2021-11-02 20:42:10 [warn] Cancelled printing file 0:/gcodes/cable_clinger_v0.gcode, print time was 0h 0m 2021-11-02 20:42:10 [info] Event logging stopped
config file attached for reference: config.g
o_lampe last edited by
; Lift z so we don't crash
G91 G1 Z10 F800 H2 G90
There are many invalid z-lifts in your files (without H2). I'm sure they are ignored by RRF.
This quoted one looks better, but I'd put the G90 in a separate line and add M400 afterwards. Just to make sure, the printer is in absolute mode when you move X,Y.
That's how I interpret the error message "Error: G1/G2/G3: intermediate position outside machine limits"
@o_lampe this config has been working for over 6 months without a hitch. Its just yesterday with the failed U axis home that I had the error, and the Z homing failed.
Also, why would I need H2 on Z-lifts? I'm using a 3xZ configuration and I'm moving the bed normally. What's your thinking behind this suggestion?
@t3p3tony yes, that's the question. nothing for the firmware, config, etc. had changed.
The only thing that I can be sure happened during this whole event was that my U axis (for my tool lock) failed to home, and that threw off the Z homing macro's first couple of steps to move the carriage to the middle of the build plate.
That's about as far as I can tell. So the question would now be: Why was the error thrown and why did the macro fail to move the print head (I'm assuming the error is from line 9 of the homez.g: G1 X155 Y155 F42000
U axis (for my tool lock) failed to home
any idea why?
that threw off the Z homing macro's first couple of steps to move the carriage to the middle of the build plate
If you U is un homed, do X and Y move normally with your config? They should do as far as I can see but worth a test to understand if that could be the cause.
I assume its too late to check if X and Y say there moved to the middle (and did not) or they report that they never moved (i.e. the position is still where they were before homez was called.
H2B last edited by H2B
U Axis failed to home due to a physical problem with the physical state of the U stepper (to skip over the details: it completely failed to home).
I have non-homed axes movement allowed in my config, so it shouldn't have impacted the movement of X and Y in the homez.g macro. I feel like it may have something to do with how macros are called when an error is triggered. For example, G1 error thrown in homeu.g, sent to console for display, but in the background the next macro is called and the first G1 command is skipped due to the error from the previous step. This may have been the case, but I'm not certain.
Also X and Y were at their endstops, so they definitely didn't move at all. You're right, its too late to check (and I'm not ready to try and recreate this event!) if DWC reported different coordinates for those axes..
You're right, its too late to check (and I'm not ready to try and recreate this event!)
Obviously we don't want any more dramatic leadscrew disassembly events, but it might be worth seeing if you can recreate this under controlled conditions:
- Cause the U axis to not home in the same manner
- see if the homeZ still fails to move X and Y.
- be ready to hit the trigger manually to stop Z before any issues happen.
While this may have been a very fluky one off it would be nice to understand what happened, if we can.
@t3p3tony I've tried recreating it by removing the endstop connection, stalling the stepper during homing, etc. etc. but I can't seem to recreate the same error message I've had, and the printer still runs the Z home macro flawlessly. I'm honestly quite perplexed and chalking this one up to RRF beta gremlins
Thanks for the help in all cases!