Tip of the Day 28 - Restarting a stopped print

[KeyboardWarrior]

This is something I personally find myself doing quite often. Whether the printers nozzle gets jammed, the filament gets kinked, the printer loses power, or any number of things occur, it's always nice to be able to restart a print and not lose the time/material invested.


Restarting a failed print: (Applicable if you're able to home your Z-axis)

1) If you can home your X, Y and Z axis without crushing your print, I would recommend doing so using the Machine Control Panel (one axis at a time). If you can't do this step, please go to the other section "Restarting a failed print, method 2",

2) From there, you would want to go the Advanced tab of the process settings and use the "Start at Printing Height" to set the height of where the print failed. I've used the machine control panel to jog to measure this value, a ruler, and calipers as well. Some machines may even have this information displayed on the LCD which would also help.

3) Go the the Scripts tab-->Starting G-Code and make sure that there aren't any travel movements that will run your extruder into your part. For instance, on the MakerBot Replicator 2 profile, the Starting script has the printer move to the front left corner of the build-plate, this would definitely cause issue. If you go through and remove any line that start with G1 you should be alright (especially if you've already homed your printer).


Restarting a failed print, method 2: (If you are unable to home the Z-axis)

---For this method, it would be if you are unable to home your Z-axis without crushing your part.

1) Go the Advanced tab of the process settings and use the "Start at Printing Height" to set the height of where the print failed. Using a ruler or calipers to measure your Z-height. Some machines may even have this information displayed on the LCD which would also help.

2) Go the the Scripts tab-->Starting G-Code, this is where we'll have to make some changes.

-->Get rid of the G28 command. This would home your printer in the X, Y and Z axis which would crush your part. Instead, replace it with the following three lines:

G28 X0 ; Home X-axis
G28 Y0 ; Home Y-axis
G92 Z"Current Z-height" ; Tells printer where the Z-axis is at, do not put in the quotes

**The G92 Z## command is very important. Since you are not homing the Z-axis, the printer would not know where the Z-axis is at without this command. If your printer is at 50.4 mm above the build plate, and that's the height you placed in your "Start at Printing Height" value in the Advanced tab, then you'd want to place in "G92 Z50.4 ;"**

Then go through and also remove any G1 commands (movement commands) in the Starting script as those would also cause issue. For instance, if there's a command that's "G1 X100 Y0 Z0.5 F3600", that command would run directly into your part since it would be moving the Z-axis down to 0.5 mm. If you'd like to keep a prime value such as G1 E15 F3600, that would work since there are no X, Y or Z values in that line.

[DarthRevan]

This is great stuff. These Tip of the Days have really helped me become a more educated user.

[siwek]

My Jog controls do not stick after a change is made?
Drivin me nutty

[DarthRevan]

Are you talking about the macros? I think they covered this in one of their videos about the firmware configuration files needing to be saved and selected in the G-code tab. https://www.youtube.com/watch?v=NYPUAqT4UyI

[RomeFallsAgain]

My startup G-Code doesn't have a single G28 code in it...
It appears my machine uses G161 and G162 for those homing commands

; **** Replicator 1 dual start.gcode ****
M73 P0 ; Enable build progress
G162 X Y F3000 ; Home XY maximum
G161 Z F1200 ; Home Z minimum
G92 Z-5 ; Set Z to -5
G1 Z0 ; Move Z to 0
G161 Z F100 ; Home Z slowly
M132 X Y Z A B ; Recall home offsets
M135 T0 ; Load right extruder offsets
G1 X-120 Y-70 Z30 F9000 ; Move to wait position off table
G130 X20 Y20 Z20 A20 B20 ; Lower stepper Vrefs while heating
M126 S[fan_speed_pwm] ; Set fan speed
M140 S[bed0_temperature] T0 ; Heat buildplate
M134 T0 ; Stabilize bed temperature
M104 S[extruder1_temperature] T1 ; Heat left extruder
M133 T1 ; Stabilize left extruder temperature
G130 X127 Y127 Z40 A127 B127 ; Default stepper Vrefs
G92 A0 B0 ; Zero extruders
M135 T1 ; Load left extruder offsets
G1 X-100 Y-68 F9000 ; Move to front left corner of bed
G1 Z0.3 F6000 ; Move down to purge
G1 X90 Y-68 E24 F2000 ; Extrude a line of filament across the front edge of the bed
G1 X100 Y-68 F180 ; Wait for ooze
G1 X110 Y-68 F5000 ; Fast wipe
G1 Z1 F100 ; Lift
G92 A0 B0 ; Zero extruders
M73 P1 ;@body (notify GPX body has started)
; **** end of start.gcode ****