# Cura slicer, enforce Z move before layer change

I am slicing with Cura and Slic3r and one important thing that I recently took my attention is that cura positions head in start point of the new layer and then lifts the nozzle. That caused my few printouts to fall as they collided with the nozzle.

Slic3r behavior is different: it raises the nozzle in last printed point and then moves to a new layer starting point (which for me is more obvious)

Is there a way to instruct Cura to lift nozzle before it goes to the starting point of a new layer? excluding Z-hops.

• You sure of that? Nobody else is complaining about Z-interference (unless you've found some forum links) from Cura slices. I suspect you're dealing with overextrusion or some such. Jul 9 '18 at 15:20
• @CarlWitthoft with 0.4 nozzle and 0.2 layer is okay. With 0.32 layer I'm running into issues Jul 9 '18 at 15:31
• A 0.32 mm layer is slightly over 75% of the nozzle diameter which is regarded as the maximum, try 0.28 mm or 0.24 mm instead.
– 0scar
Jul 9 '18 at 16:49

To lift the head to prevent the nozzle to tip over your print you could use an option called Z hop in Cura. Just enter hop' in the search box on the right side to make those options magically appear (in a recent version of Cura, e.g. version 3.x.x).

Other than Z hop there is no default action, or series of commands, per layer to be specified before the start of the layer. There are 2 other ways to circumvent this:

1. The first is saving you G-code to file and open the file in an advanced text editor (e.g. Notepad++). With a (recorded) macro you can find the words ;LAYER:, which are inserted by Cura before each layer starts, and insert a pre-copied list of commands that set the movement in relative mode, move Z up 2 mm, set into absolute mode again. When the next layer starts the extruder goes to the layer start from a 2 mm rise.
2. Write a plugin for Cura to post-process (C:\Program Files\Ultimaker Cura x.x\plugins\PostProcessingPlugin\scripts) the G-code file to inject the code to Z hop before the start of every layer, or a plugin that adds a new option and/or category to the slicer settings sidebar of the GUI.
• that is not an option..... shall add that to question. this will extend printing time by 3 to 4 times as was trying that... Jul 9 '18 at 10:38

OK, after going via all the options I found that CURA has a combing mode which reduces retraction and offers another option which is Avoid Printed Parts When Traveling.

That solves my problem.

• Good to hear that you found a workaround that works for you, but technically your answer does not answer the question Cura slicer, enforce Z move before layer change or Is there a way to instruct Cura to lift nozzle before it goes to the starting point of a new layer?`
– 0scar
Jul 15 '18 at 18:28
• @0scar please read this twice: 'Keep an open mind The answer to your question may not always be the one you wanted, but that doesn’t mean it is wrong. A conclusive answer isn’t always possible. When in doubt, ask people to cite their sources, or to explain how/where they learned something. Even if we don’t agree with you, or tell you exactly what you wanted to hear, remember: we’re just trying to help.' source: 3dprinting.stackexchange.com/help/how-to-ask and the main point is that asking a question is a part of creating the solution! Jul 15 '18 at 21:40
• Why not change the question to include "or another method to avoid hitting the print" and expand your answer where you say you address the avoidance of the printed parts, then it would be a correct answer!
– 0scar
Jul 16 '18 at 5:58