Finding the 'Z' height

How To Recover A Failed Print

This solution can help you recover your print if it failed due to the following reasons:

  • Extruder jammed in the middle of a print
  • Power fluctuations caused the printer to restart
  • Extruder ran out of filament (assuming you do not have filament sensors installed)

The first thing you have to do is find out the height at which the print needs to be resumed from. The best way to do this is to move the extruder carefully using the ‘Move’ command such that the tip of the nozzle is barely touching the part. Note down the Z position on the control box. This is the height you need to look for in the g-code.

Let’s say you were printing the Eiffel tower. The part failed at a ‘Z’ height of 29.55 mm. We look for ‘Z29’ in the g-code using (CTRL+F). Since this was printed using a layer height of ‘0.3 mm’, the Z value greater than and closest to 29.55 mm was found to be 29.7.

3D-Print-CAD Model
Figure 1: Model

This solution can help you recover your print if it failed due to the following reasons:

  • Extruder jammed in the middle of a print
  • Power fluctuations caused the printer to restart
  • Extruder ran out of filament (assuming you do not have filament sensors installed)

The first thing you have to do is find out the height at which the print needs to be resumed from. The best way to do this is to move the extruder carefully using the ‘Move’ command such that the tip of the nozzle is barely touching the part. Note down the Z position on the control box. This is the height you need to look for in the g-code.

Let’s say you were printing the Eiffel tower. The part failed at a ‘Z’ height of 29.55 mm. We look for ‘Z29’ in the g-code using (CTRL+F). Since this was printed using a layer height of ‘0.3 mm’, the Z value greater than and closest to 29.55 mm was found to be 29.7.

Finding the 'Z' height
Figure 2: Finding the 'Z' height
Z' height on the control box
Figure 3: 'Z' height on the control box

The method of recovering a print might be slightly different depending on the slicer you use, due to difference in the style of g-code generated.

For Ultimaker Cura:

STEP 1: Select all layers before that layer (LAYER:98 to LAYER:0 in this case) and delete it. Do not delete the commands at the very beginning of the g-code that set the extruder temperatures, home the axis, etc. as shown below.

ulitmaker-gcode
ulitmaker-gcode

STEP 2: Raise the extruder such that it is at least above the layer from which you want to resume your print. This is to make sure the nozzle does not crash into your print when it restarts. To do this, modify the highlighted line and replace it with the new height.

ultimaker-gcode
ultimaker-gcode

STEP 3: Locate the line that sets the Extruder axis and copy the value in the line as shown below.

ulitmaker-cura-gcode

STEP 4: Add the line ‘M106 S100’ to turn on the fan and set the fan speed. This line might be missing in the g-code as the fan is not turned on for the initial few layers to improve bed adhesion.

ulitmaker-cura-gcode

STEP 5:  Save the g-code file and print it to resume your print from the Z height. Make sure you clean off any blobs of material left behind by the nozzle on the top of the print.

For Simplify 3D:

The method of recovering a print from Z is easier with a Simplify3D generated g-code.

STEP 1: Locate the layer height to resume the print from and delete the entire g-code before that layer.

STEP 2: Make sure the bed and extruder temperatures are set to the correct values on the printer.

STEP 3:  Save the g-code file and print it to resume your print from Z.

Also, if you know the exact height from which you want to start printing, you can also use the ‘start printing from height’ feature in Simplify3D.

Go to > Edit Process Settings> Advanced> Layer modifications and set the height.

Although these are very effective methods to save a print, an irregular/odd layer might be visible at the height from which your print was recovered. But this can be easily sandpapered to make it smooth.

For more information and tips visit us at https://3dplatform.com/ and don’t forget to follow us on TwitterFacebook and LinkedIn. And as always, if you have any questions about 3D printing or our printers, please contact marketing@3dplatform.com and we will be happy to assist you.

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