Tips and Tricks: Maximizing Bed Adhesion with Cura LE

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2024-03-14 | By Lulzbot

License: See Original Project 3D Printing

Guide by LulzBot

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‎3D printer bed adhesion is the foundation of a successful print, but there are ‎circumstances that make adhesion a challenge, even if your PEI surface has ‎been properly maintained.‎

3D models don't always load in Cura LulzBot Edition with the optimal orientation ‎for printing
Some 3D models lack a flat surface or obvious base
Some models have minimal surface area for bed contact in any orientation
Certain filament materials are more prone to warping or curling

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The following LulzBot 3D printer tips and tricks will help you improve those challenging ‎‎3D prints by maximizing print bed adhesion during the printing process.‎‎ ‎

Optimally Orienting Your Model

Models do not always load in Cura LE with the optimal orientation. Before you begin ‎printing, it's always a good idea to consider how rotating your model could potentially ‎improve bed adhesion and overall print quality. Your goal is to maximize print bed ‎contact and layer bonding while minimizing the number of overhangs and bridges.‎

Note: The maximum overhang angle your LulzBot printer can successfully produce is a ‎factor of the material being used, the layer thickness, the cooling fan speed, and the ‎tolerance for surface imperfections for a given use case. If you're not sure how shallow ‎of an angle the filament can handle, try printing an overhang angle test object.‎ ‎

In Cura, select your model, then select the Rotate icon on the left-hand side of ‎your screen.‎‎
The Rotate tool gives you the ability to orient your model along three axes. The ‎red circle will allow you to rotate around the X-axis. The blue circle will rotate ‎around the Z-axis. The green circle will rotate around the Y-axis.‎‎
When you’ve found the optimal side to print as the base, use the Lay Flat icon to ‎ensure that the flat portion of your print is securely attached to the print surface. ‎It is highly recommended to use this option after rotating your model on the Z-‎axis as it will help prevent adhesion issues during the print.

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Note: Adding brim to your print can help improve adhesion as well. Brim adds concentric ‎perimeters around the base of the print, better adhering the print to the heated plate. ‎This is only one layer thick, and easily removed post-print. To add Brim to your print, ‎select Custom Print Setup, and then select Brim under Build Plate Adhesion Type.‎‎ ‎‎

‎Tricks for Improving Adhesion

By altering the model, itself, you can be much more selective in how the model is printed. ‎Here are four methods to get you started manually altering your models.‎

‎1. Drop the Base‎ ‎

Depending on how you intend to use your printed object, you can lower the model’s Z-‎axis in order to create a greater surface area in contact with the bed. The model will lose ‎some of its height but will widen the base in the process, stabilizing the print with ‎improved bed adhesion.‎

This technique works well for organic shapes likes models of bones, artifacts, and ‎sculptures. Spheres are a good example because Cura shows the section of the model ‎that is too steep to print in red. Simply select the blue Z-axis arrow and move your model ‎downwards slowly until the red area is underneath the print surface, creating a 30-‎degree print angle or less.‎

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‎‎2. Divide and Conquer‎

You can use a similar technique to effectively cut your model in half, and then bond the ‎halves together with glue. Using this technique, your model won't have an artificial flat ‎surface, but will have a glue seam.‎

Take note of the total height of the Z-axis by selecting the model and then Scale. Divide ‎the number in half and write it down. Then select Move and enter the number into Z as ‎a negative value. You should now see half of the model pushed down below the print ‎surface.‎

If your model is symmetrical all around, like a sphere, simply right click the model and ‎make a duplicate, and repeat dividing it in half.‎

If your model is asymmetrical, right click the model and make a duplicate, then rotate the ‎duplicate 180 degrees along the Y-axis, until it’s completely upside down. Type in a ‎negative Z value for half the Z-axis of your object and hit enter.‎

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‎3. Mouse Ears‎ ‎

*Requires modeling software

Mouse ears are an excellent method for increasing adhesion of warp-prone materials like ‎ABS or Nylon, particularly if your model has limited print surface contact. Note that the ‎mouse ears will need to be manually cut off of your model after printing.‎

Download a mouse ears stl file, then in your modeling software, place the single-layered ‎discs (mouse ears) through areas with poor print adhesion. Make sure the mouse ears are ‎a single-layer tall, and then center the mouse ears around any section of your model that ‎might warp during printing. This added layer will create a greater bond to keep the print ‎steady and help prevent warping.

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Example Scenario: How to Print an L-Shaped Pipe

Using this L-shaped pipe model as an example, take a moment to imagine how the tool ‎head would move during printing. From the bottom up, layer by layer, you can tell the ‎print would have difficulty adhering to the bed because there isn't a flat base to build on. ‎What a perfect opportunity to use one of the techniques discussed earlier!‎

Drop The Base wouldn't be appropriate here because the model is mechanical, and ‎altering the shape would affect the functionality. Instead, try the Divide and Conquer ‎technique - sinking half the model through the surface, duplicating, rotating 180 degrees ‎if needed, moving the halves apart, printing, and the adhering the halves together. Once ‎this has been set up in Cura, adding Brim to the Build Plate Adhesion settings will help ‎ensure that each half maintains a strong bond during printing.‎

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