3. 3D printing with PrusaSlicer#

An essential tool of this course is 3D printing for which we learned to use PrusaSlicer.
PrusaSlicer is a software that mainly allows your to convert a 3D model in STL (and other) in a G-code usable by a 3D printer (I3 M3KS).

Getting started#

On PrusiaSlicer, you can import your STL file (and other) simply through File/Import. Nevertheless I had some problemes regarding dimensions when I did it this way. Which is why I find it best to go find your STL file and “open in with PrusiaSlicer”.

Before anything else, it is important to verify you have the correct parameters for your 3D printer. Printing parameters

In our case we had to change the presetting of the printer section. Select the small button on the right of the “Imprimante” section and click on “Ajouter/Supprimer des préréglages”. Go to “Prusia Research” and find your corresponding printer settings.

The following printing options are important to understand for the good execution of your 3D model.

Infill#

  • Filling density
    Amount of material (in %) inside your 3D model. Bigger percentage implies more printing time. Solidity doesn’t increase over 35% !! Aim around 15%.

  • Filling pattern
    You may choose the pattern of your filling. The pattern may influence the solidity and flexibility of your model. Some aren’t symetric on all 3 axes so think of the ortientation carefully.

Skirt and brim#

The skirt’s main purpose is to stabalize the flow of the filament through the nozzle. It also allows to verify the adhesion of the platter.

The brim is to stabalize the base of your model. It isn’t always necessary but is preferable for small objects or bigger ones with a small proportion of their surface touching the platter.

Support material#

For models without enough stability it is necessary to add supports. If the option is selected, they will be automatically generated after slicing. You can nevertheless add them yourself with the “painted supports” option (shortcut L). Keep in mind supports also add printing time.

A first test#

I printed the airplane beam model built with openSCAD in the previous module.

Checklist

  • Clean the platter with a tissue and alcohol to assure good adhesion.
  • Filament type is correct
  • Nozzle and platter reached the required temperature - (PLA: Platter 60°C - Nozzle 215°C)
  • Filament is correctly inserted

During the printing processa a problem occured. A little bit of PLA was above its layer. Even though it doesn’t look problematic at first it can seriously ruin the rest of the printing.
In this case, select Pause print in the menu. The nozzle will get back to it’s default position allowing us to clean the structure and the nozzle itself if necessary. Then simply select Resume print.

Unfortunatly for me the problem persisted a bit. I think it is because the filament is still hot and comes out by itself even before the printing resumes. In the end, the printing managed to take on normally, leaving behind a little bit of empty space.

3D model of AB Space on 3D model of AB

This flexlink is built to have two stable positions if its two beam tips are fixed in space. This way it can act as a switch, going from one stable state to the other. For this mean, our beams must be flexible enough to be bent from one side to the other.
Our model worked at first but after a few tries it broke. The repetability of the switching wasn’t achieved.

Broken AB 3D model

Changes brought:

  • Increase the bar’s height
  • Decrease the width of the beams
  • Created a rounded angle at the intersection between the beams and the main body - we can see it is there that our model broke

The new version seems much more flexible and doesn’t break when bending it.

Download STL file

Mechanism#

To test out my flexlink, I needed a lego type bar that could go with it. Unfortunatly, none of my co-students had made a flexlink of this type. While checking the documentation of Lou Ferir, I saw he had found what I was looking for in last year’s course: Noa Lipmanowicz made the following flexlink:
Lego bar Download SCAD file

Download STL file

The licence she chose allows me to use and modify her work. I thus decided to rend her code a little more parametric in order to choose specificely how many holes and outward cylinders I wanted. I also decided to take out the cylinder’s on top of the bar as they don’t print out well if not in the z axis of the printer and more importantly won’t serve any purpose in this case.