3D printing elephant foot ➡️ This is how you solve the problem•
Posted on July 31 2023
If the first layer of the 3D print is wider than intended, it is called an "elephant foot". The problem is common in 3D printing and quite annoying - not just for aesthetic reasons! In this article you will learn step by step how to avoid 3D printing elephant foot and achieve clean print results.
How do you recognize an elephant's foot in 3D printing?
An elephant's foot is easy to recognize: at the base , the print object expands , as if the material were being pushed outwards. The shape is comparable to a real elephant's foot or the plant of the same name - the name is no coincidence!
The characteristic deformation is not only annoying for reasons of optics. In the case of functional printed objects, it can lead to them being unusable because parts no longer fit together properly.
The elephant foot deformations can have different causes. The most common are:
- Overextrusion of the first layers: When printing the first layer(s), too much material comes out of the nozzle, which is then pushed to the side.
- Nozzle is too close to the print bed: When the nozzle presses on the first layer of extruded material, it is pushed to the side. The phenomenon is also known as baby stepping or z-stepping.
- Poor Adhesion: The printed object may stretch even if it is not properly adhered to the printing platform. This can happen if the print bed is not properly calibrated or if the print bed surface is not suitable.
- High bed temperature: Too high a bed temperature can cause the material to become too runny, causing the lower layers of the object to spread.
Depending on what triggers the elephant foot when you press, there are different solutions to the problem. More on that in the next section.
Do you keep finding that your print objects are getting wider at the base? There are several ways to avoid these elephant foot deformities:
- Print bed calibration
- Software Settings (First Layer and Print Temperature)
- Auxiliary constructions (raft and chamfer)
I recommend that you use the following solutions step by step . This way you can be sure that you rule out all possible causes with the least possible effort. With a bit of luck, you can solve the problem by leveling the print bed. In the worst case, none of the settings help and you have to resort to an auxiliary construction.
An elephant's foot can arise, among other things, because the nozzle is too close to the print bed. The emerging filament then does not have enough space and is squeezed to the side.
To ensure that the nozzle is the correct distance from the print bed at every position, perform a calibration (leveling) of the print bed . Note that the exact procedure may vary depending on the 3D printer model. So be sure to check your printer's instructions for proper calibration.
Basically, manual calibration works as follows:
- Start your 3D printer and bring the print head to the home position using the home or zero point function.
- Thoroughly clean the print bed to ensure it is free of dust or dirt.
- Choose a corner of the print bed and manually move the printhead until it hovers about 0.1mm above the bed's surface.
- Take a piece of paper and gently slide it between the nozzle and the print bed. The paper should brush the nozzle but still move freely.
- Turn the appropriate adjustment screw or dial for that corner of the print bed to adjust the height of the bed. This changes the height of the pressure plate in relation to the nozzle. Turning clockwise lowers the bed, while turning counterclockwise raises the bed.
- Repeat steps 3-5 for each corner of the print bed to ensure all corners are calibrated evenly.
- After calibrating all corners, run a level test to verify calibration. To do this, print a small test object that has several horizontal layers. Check the result and make sure that all the layers have adhered evenly, without one side being higher or lower than the other.
Many slicers have separate settings for the first layers. Depending on whether you use Cura, Simplify 3D or another software, you will find these settings under different names.
- first/ initial layer height
The layer height of the first layer is usually greater than that of the other layers. So more filament is output. The reason is that this is intended to increase adhesion because the material is pressed onto the bed with more force. But if there is too much material, it can easily become an elephant's foot.
- first/ initial layer width
Usually the line width of the first layer is the same as the rest of the printed object. However, adhesion can be improved by setting it slightly higher (e.g. 120% compared to the rest of the layers). But this can also easily lead to the unsightly elephant foot look.
- first/initial layer flow rate
Flow rate in 3D printing refers to the amount of filament that flows through the 3D printer’s extruder per unit time. If it is set too high, too much filament can come out, which is then pushed to the side.
- First/ initial horizontal expansion
In some slicers you can also set the horizontal extension for the first layer - this describes the entire dimension of the object on the XY axis. The larger the value, the wider the first layer will be. Conversely, you can shrink the first layer by setting a negative value (e.g. -0.1). This can prevent over-extrusion and thus the elephant foot.
To reduce the risk of elephant foot formation, you can adjust the first layer setting:
- Increase the layer height.
- Decrease the line width.
- Decrease the flow rate.
- Decrease the horizontal expansion.
Be sure to do this in small steps (e.g. 5%) and make test prints in between until you get the desired result.
Too high a temperature can result in a softer material that spreads sideways. So check the recommended print bed temperature for the filament used. If the temperature in the slicer is set too high, reduce it to the temperature recommended for the filament.
A raft (= additional layer under the object as an auxiliary construction) ensures that the actual print object is not affected by the elephant's foot, but only the lower raft layer, which is later removed. Note, however, that print time and filament consumption may increase. In addition, this solution does not address the causes of elephant foot and is more of an emergency solution.
To use a raft, activate the raft function in the printer software and adjust the settings (layer thickness, print speed, spacing, offset).
If you print your own design, you can integrate a circumferential chamfer on the lower side of your model. This 2-3 layer high edge gives the material more space for the next layers.
Depending on the model, the bevel should be between 0.3 and 1 mm thick and have an angle of no more than 45°.
As with the raft, the bevel is an effective remedy for the elephant foot problem, but it doesn't "get to the root". Therefore, you should first try to solve the problem by adjusting the pressure settings and only working with Raft or Chamfer when nothing else works.
Remove elephant foot
Of course, you also have the option of accepting the formation of an elephant's foot and removing it afterwards in post-processing. This works best with a so-called deburring tool, with which the excess material is scraped off.