Slicer software is becoming more advanced day by day, adding new experimental features that can become helpful to make 3D printing easier by solving some of the commonly encountered issues during printing.
As nothing is as straightforward as it seems in the 3D printing world, some of these features aren’t always beneficial for all printers and all scenarios and may even produce worse results when you enable them.
Today, we will be discussing one of the most commonly talked about experimental features, known as z-hop, or vertical lift, depending on the slicer software you use.
So, what is z-hop, and should you enable it on your slicer?
Z-hop (vertical lift) is an experimental feature that causes the printhead to move up or the build plate to move down (depends on the type of the printer) by a slight margin after a retraction.
The primary thought behind the z-hop feature is to prevent plastic from blobbing by creating a small distance between the nozzle and the object.
As there are mixed opinions about the z-hop feature due to varying results, we can only recommend experimenting with it yourself and see whether it gets you good results.
Z-hop is definitely an innovative solution to prevent blobbing, but it clearly doesn’t work as intended in every scenario, considering the mixed feedback within the community.
Let’s take a deeper look into the z-hop feature to really understand how it aims to prevent blobbing and why the 3D printing community has mixed opinions on it.
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What is Z-Hop (Vertical Lift)?
Z-hop, also known as vertical lift, is an experimental feature you can enable in most of the popular slicers such as Cura, PrusaSlicer, and more.
When you enable the z-hop feature in the slicer, the printer creates a gap between the nozzle and the object you are printing by either lifting the printhead or lowering the build plate right after filament retraction.
In most slicers, it’s also possible to configure the z-hop height, which allows you to experiment and find the distance that works best for your printer.
The primary reason behind this feature’s creation is to prevent blobbing, an issue that most 3D printing enthusiasts have at least encountered once in their life.
Blobbing is an issue where “blobs” of melted plastic appear on the printed object due to over-extrusion. A multitude of factors can cause this issue, but the most common culprit is incorrect retraction settings.
The z-hop feature aims to combat the blobbing issue by separating the nozzle and the object, essentially making it impossible for the object and the melted filament to come into contact.
While the z-hop feature does indeed do a fantastic job of preventing blobbing in most cases, it sometimes introduces the issue of stringing, which is the reason behind the mixed opinions on this feature within the community.
Should I Enable Z-Hop?
If you are having issues with blobbing, enabling z-hop may sound like the quickest solution to your problems as it does not require a lot of configuration to work.
As z-hop is an experimental feature that may bring the issue of stringing with it, we can only recommend enabling it if you still have blobbing-related problems after ensuring that you have configured the following settings correctly.
- Retraction speed
- Retraction minimum travel
- Retraction distance
- Travel speed
- Print speed
- Nozzle temperature
The incorrect configuration of the settings we have listed above is often the reason behind blobbing (and stringing), and correctly configuring them solves blobbing and stringing issues most of the time, meaning that there won’t be any need to enable z-hop.
If you still have problems with blobbing even after configuring these settings correctly, you can experiment with the z-hop feature and see if it manages to fix your issues.
How Do I Enable Z-Hop?
As the process for enabling the z-hop feature varies between slicers, it’s not possible to give a definitive answer to this question.
That being said, we have the next best thing for you, which is a list of widely used slicers and how you can enable z-hop in them.
- Cura – You can enable z-hop by checking the Z Hop When Retracted checkbox located in the Travel section of the print settings and configure the z-hop distance by inputting a value into the Z Hop Height box.
- PrusaSlicer – You can enable the z-hop setting by going to Extruder 1 in Printer settings and inputting a value in the Lift Z box.
- Simplify3D – Select the Extruder tab in the Edit Process Settings menu, enable Retraction, and set Retraction Vertical Lift to a value greater than zero.
- MatterControl – Input a value greater than zero in the Z Lift box located in the Retraction sub-menu of the Filament menu in settings.
- Slic3r – Go to the Extruder section of the Printer tab, and fill the Lift Z box with a value greater than zero.
While the placement of the feature shows a difference between slicers, enabling z-hop is a straightforward task in every single one of them.
What Is a Good Z-Hop Distance?
As the optimal z-hop distance varies on the layer height you use, it’s impossible to find a value that fits all scenarios.
As a rule of thumb, start by setting the z-hop distance to the same value as the layer height and increase in increments of 0.1 millimeters (mm) until you don’t experience blobbing anymore.
For instance, the default layer height is 0.2mm in most 3D printers with a standard 0.4-millimeter nozzle, meaning that you can set the z-hop distance to 0.2mm as the starting value.
If the starting value has solved your blobbing issue, you most likely don’t need to tinker with it anymore, but if you have started with a value that is too high, you may want to gradually decrease it to find a balance where you don’t experience blobbing and stringing is minimal.
Does Z-Hop Cause Stringing?
The biggest complaint about the z-hop feature is that it indeed can cause stringing.
Since the z-hop feature eliminates blobbing by lifting the printhead up to prevent the nozzle from wiping the excess plastic on the object, the plastic comes out of the printhead as it travels instead, leaving strings behind it.
While stringing, similar to blobbing, has mostly to do with incorrectly configured retraction settings, there is no denying that the way the z-hop feature works amplifies the stringing problem.
Because of this, we highly recommend taking the time to configure retraction settings as correctly as possible before moving on to enabling a feature such as z-hop.
Z-hop (vertical lift) is definitely a fantastic addition to slicers for fixing blobbing issues, but we can only recommend using it as a last resort solution due to the stringing problem it may bring.
While correctly configuring settings such as retraction speed and retraction distance can take a considerable amount of experimentation and effort, the correctness of these settings is vital for your printer to function optimally.
As a result, we highly recommend not thinking of z-hop as a magic feature that you can enable to solve blobbing issues but more of a safety net that you can use if nothing else works.
Mike started his 3D printing journey with the Anet A8 when it first came out back in 2017, and has been obsessed with 3D printers ever since. Nowadays, he primarily uses his Ender 3 to print functional parts that make his life more convenient whenever possible.