Polylactide (PLA) 3D printed model


I created and printed a 3D model of a polylactide polymer (3 monomers) out of PLA (or polylactide) as a fun project to make myself familiar with 3D printing.

Step 1

Generate the .mol file

To create the .mol file of polylactide I decided to use the easy-to-use website MolView. Simply write the line model of your molecule using the tools on the left and click 2D to 3D to preview. Finally choose Tools > MOL file to export the molecule as a .mol file.

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Step 2

Convert .mol file to .pdb

I chose to use Avogadro for this. Simply import the .mol in Avogadro and select File > Save as... (not export!) and choose .pdb as the format.

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Step 3

Convert .pdb to 3D model

I used the free 3D modeler Blender for this. Before you can import .pdb files in Blender, you'll have to enable the Add-on for it. Go to File > User preferences > Add-ons and search for pdb. Make sure that Community and All is checked and check the box next to the Add-on.
Now go to File > Import > Protein data bank and select your .pdb file. Make sure you use these import settings.
For some reason the double bonds weren't showing up for me, so I just added them manually after import. Finally export the model in the format of your choosing. .stl works with most printer software, but I had to use .x3d because the .stl wasn't loading correctly.

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Step 4

Print the model using your printer software

I used an Ultimaker printer so I went with Cura. Open the model file in Cura and customize the size to your liking, but make sure it's big enough! My first try was with a length of about 10 cm, which was way too small and brittle.
I doubled the size and used semi-transparent PLA on my second try.
Remember to lay your object flat and choose 100% infill. Support is definitely necessary.

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Step 5

Finishing touches

Originally I planned on removing the support but it proved rather difficult and the model looks pretty cool like this too. So I just removed the leftover gunk and ended up with this.


Getting familiar with 3D printing and a fun pun.

Discuss this Project on discuss.fablabs.io