Posts: 13
Joined: Wed Jan 07, 2015 10:32 am

Re: Start Printing at height ....

Fri Sep 04, 2015 4:34 pm

Answering my own post. The diagonal sequence I was refering too is editable in the gcode scripts tab. I do not remember if ot comes by default for that printer. But if so, it would be nice to change the default.

Posts: 1436
Joined: Sun Feb 16, 2014 10:52 am

Re: Start Printing at height ....

Sat Sep 05, 2015 6:41 am

The sequence that the machines does at the start of the print is controlled by the starting gcode. If you don't want it to do the diagonal move, just go to the Scripts tab and edit your starting script.

For example, in the Replicator 2 starting script it homes the axes to the back right, then has the following command:
G1 X-145 Y-75 Z30 F9000 ; move to wait position

Just change that to
G1 X145 Y-75 Z30 F9000 ; move to wait position (note that X is +145mm, not negative)

or something similar if you want it to move to a new location

For pausing the print at various heights, I believe both the Makerbot and Sailfish firmwares allows you to do this very easily. Just use the LCD panel and you can set the Z-position where you want the machine to pause.

Posts: 3
Joined: Thu Feb 04, 2016 6:07 pm

Re: Start Printing at height ....

Thu Feb 04, 2016 8:35 pm

Hi folks!

I just did it! Printed something with carbon filament, which really likes to clogg if not enough throughput is on the nozzle. So I canceled the print, took my digital calliper and measured the printed height was 12,8mm.

To continue printing at this height you have to lower the model 12,8mm below the printing surface. The printed part will be skipped automatically if it is below the build level.

Next thing is to modify the Starting script g-code in the "Scripts" tab. This script basically does the adjustment routine before the printing starts. Last thing it does is extruding some filament on the most outer side of the build platform and then printing starts. You have to make sure to move the build plate out of the way before the extruders go into the wait position for heating up.


Basically I added G-Code to move the platform downwards to the last printed layer before the extruders are moved into the waiting position. It started printing exactly 12,8mm where the last build failed.

Here is the G-Code:

Code: Select all

; **** 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
G1 Z7.44 ; Move Z to 7.44 to restart printing at this position
M132 X Y Z A B ; Recall home offsets
M135 T0 ; Load right extruder offsets
G1 X-120 Y-70 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[extruder0_temperature] T0 ; Heat right extruder
M133 T0 ; Stabilize right extruder temperature
G130 X127 Y127 Z40 A127 B127 ; Default stepper Vrefs
G92 A0 B0 ; Zero extruders
G1 X100 Y-73 F9000 ; Move to front right corner of bed
G1 X-90 Y-73 E24 F2000 ; Extrude a line of filament across the front edge of the bed
G1 X-100 Y-73 F180 ; Wait for ooze
G1 X-110 Y-73 F5000 ; Fast wipe
M73 P1 ;@body (notify GPX body has started)
; **** end of start.gcode ****
Add Line 8: "G1 Z7.44 ; Move Z to 7.44 to restart printing at this position"
G-Code to level build plate to the last layer after failing. Note that I had to subtract 5mm due to the adjustment in Line 5, where the Z-Axis gets set by -5mm. Better to keep this since things can get weird if the axis are not zeroed as expected by the printer.

Modify Line 11: "G1 X-120 Y-70 F9000 ; Move to wait position off table"
Removed instruction to move the build plate (Z-axis) because we adjusted it in line 8 to make sure extruders won't move into the already build object.

Remove the following two lines at around line 20 and 24 so the build plate stays on the last printed layer:
"G1 Z0.3 F6000 ; Move down to purge"
"G1 Z0.5 F100 ; Lift"

At the beginning try to remove any oozed out filament by hand before the printing continues.

As I mentioned before: This procedure is risky! You might damage your printer if you are not very carefull or even hurt yourself while fiddling around. Try this only if you know what you are doing. I am not responsible for any damage caused to you or your printer.

Hope this helps out.

Kind regards,

Posts: 1
Joined: Fri Jan 27, 2017 8:36 am

Re: Start Printing at height ....

Fri Jan 27, 2017 8:39 am

Here's a little trick I found, it helps if you always center the print before you start, just so you have a baseline to resume from. In my case I was printing off the SD card, but use the computer right off the software to resume.

Posts: 3
Joined: Thu Feb 04, 2016 6:07 pm

Re: Start Printing at height ....

Thu Dec 14, 2017 8:04 pm

Thank you to myself for figuring this out! Just saved my ass, dude!

Posts: 3
Joined: Tue Jan 31, 2017 2:36 am

Re: Start Printing at height ....

Mon Feb 19, 2018 3:31 am

There's a lot of good stuff out there. Here's my checklist to resume a print. Your process may vary, so just sharing in case it helps someone after they crash after 10 hours of printing!!

This is the process to use when there is a problem, AND a good portion of the part is still on the bed.
1. Measure the height of the remaining print from the bed. E.g. 27.00mm
2. Determine the “Gcode Height” the print failed at (also in DIY Calcs spreadsheet).
- Open the Process that was used for the print. Determine the Layer Height (e.g. 0.3mm) and the 1st layer percentage (e.g. 90%) : Double click process | Layer, Layer Settings | Primary Layer Height, and First Layer Settings | First Layer Height.
- Number of Layers = Height / Layer Height + 1 - First Layer Percent
- Round no. of layers up or down (normally down).
- Gcode Height = (Number of Layers - 1 + First Layer Percent) * Layer Height
- For example above, Number of Layers = 27 / .3 + 1 - .9 = 90.10 . Round Layers to 90.00
- Gcode Height = (90 - 1 + .9) * .3 = 26.97
3. Save the Toolpaths to Disk.
- Edit the gcode, and search for Zxxx (e.g. Z26.97). Should be able to find it in the file - to confirm that the Gcode height is correct. If not, then something is not right, so debug the info!
4. Copy the process that was used (e.g. PLA-Fast) for the print (Click on Process, Ctl-C and Ctl V).
5. Edit the new process
- Rename it (E.g. Process Name: PLA-Fast - tmp)
- Additions | Use Skirt/.Brim : OFF
- Advanced | Start printing at height: ON. Set the start height to the Gcode Height from above.
- Scripts | Starting SCript : Adjust as needed
- If part is large and bed levelling cannot be done, remove the “Measure loop” G29.
- Hopefully can at least calibrate Z at 0 at XY=0,0, else need to figure out how to do G28 Z0.
- OK
6. Prepare to Print
7. Review the print visually. Make sure path is ok.
8. Save Toolpaths to Disk. Edit the gcode file, and check that the startup is good. Mainly check that it does go to the correct Z height and will not collide with part on the table.
- E.g. Line 223, should see G1 Z27.300 F1000.
9. In MCP, turn ON Extruder and Heated Bed to Full temp (e.g. 205, 50)
10. Home X and Home Y
11. Wait till extruder reaches temp, then Extrude 10mm of filament to make sure it is flowing.
12. Set Override Settings | Movement to 1% - super slow - be ready to turn off machine if it will crash with part.
13. Begin Printing over USB.
14. If all is correct, extrusions should be directly over part on bed, and no crashing.
15. Can now set Override Setrtings | Movement to 100% (or go slowly up to 50% for first layer to ensure all is ok)

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