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5. 3D Printing

Hero Shot of the Week

DISCLAIMER: This is not my print but happened just yesterday (the day before our global meeting).

Long story short: a med student/intern from our University Medical Department needed to print an educational model for her studies and to explain to patients what they needed to know. (Medical procedures and symptoms).
But her print was so cool that I want to share it here

❗ If you are sensitive for skeleton stuff do not look. ❗

Photo here Cranium

Summary

This is what I did this week for 3D Printing. I am already quite familiar with it. Except with resin printing, but there the printer did not want to work.

Work Process

Intro

Henk and Saco did an introduction for 3D Printing.

We first started to look at the guts of the GCode. Lots of coordinates.

I also learned that we can create the code to generate the GCode. But that seems more work than necessary 😅.

It is an old language created for CNC.

A Slow Motion video of a 3D Printer printing.

Different Materials

In our FabLab ULB we mainly use PLA. We use this filament as it one of the safest one for health concerns. It gives off no toxic fumes and has the smallest amount of released particles while printing. It is also biodegradable as it is made by lactic acid. The same stuff as one of the molecules generated in our muscles.

It is also recyclable but we never managed to do it in our Lab. When tried we had variable diameter. And for why we did not try more is because it is not one of our priorities.

A second reason on why we only use PLA is for simplicity for student. They only need to check if they have enough filament and not bother with the type. We have quite a lot of students who only comes because they are required to. So it is easier for everyone to have only one type.

That said we allow printing in PETG (and TPU) for certain occasions and/or researchers, when students are not present. But no other materials (yet).

Material Comparison Tables

From Prusa From Simplify3D

Pollution

This is an article about the release of particle while printing.

Recycling

An article about recycling.

Printers

History

The invention of the 3D Printer is quite complicated as it seems multiple people developed the same technology at (more or less) the same time without the knowledge of the other.

RepRap Family Tree

But this guy video presentation debates the first use of a "3D Printer". It is about a special concrete pourer.

Multi head Printers

With multi head we can do lots of interesting / fabulous things.

One of them is printing in multi-material. This allows us to created flexible objects like this bone hand medical example.

Programs

MeshLab

So there is MeshLab to optimize the 3D models. As the last update more than a 1 year ago I was curious if it was abandoned. GitHub says no. Last edit was a month ago.

This app should be useful for D&D figurines.

Prusa Slicer

This is the one that I use everyday. I found it quite easy to use and mostly user friendly.

Super Slicer

A fork of Prusa Slicer.

home page

FabLab Setup

So here I have, in total 16 Prusa MK3S/S+. 15 of them have 0,6mm nozzle and one of them 0,4mm nozzle. All brass nozzle.

Printers

So the 0,6mm nozzle printers are for the students to use. We moved to 0,6 for two main reasons.

  1. It prints faster as it can deposit bigger layers. We are a uni FabLab for prototyping not for precise work. The 0,4mm nozzle printer is in a separate room and only accessible for the researchers.
  2. Second reason (tbh, I cannot quite recall if it was a reason or a consequence) it was to have less clogs. The printers are less often in maintenance because of clogging issues. Most of the time when a printer has an issue is because of an overused cable that broke.

I also have 2 Ultimakers that are currently out of use.

And 1 FromLab Form 2 resin printer.

Design rules

Brick Layers

The article shared in the zoom meeting.

I was curious if it was already present in Prusa Slicer, but seems like it is not based in this open issue. But this would definitely improve the strength of the print. And maybe even its watertightness.

BUT

While in the intro Henk showed us this guy GitHub page where he made a post script to implement the brick layer technology to Prusa Slicer.

So it is not officially implemented but has people working on it.

AH

It is a patent issue...

Testing

So the Print model is the following. An all in one file for the different design rules.

I printed this in different ways:

PS: I also did a Z calibration before printing but this was for my job as some of them needed it.

0.4 Nozzle with 0.15 mm layer - PLA

15b

0.6 nozzle with 0.15 mm layer - PLA

15

0.6 nozzle with 0.30 mm layer - PLA

03

0.6 nozzle with 0.40mm layer - PLA

04

0.6 nozzle with 0.30 mm layer - TPU

Preparing my print be for TPU printing. (That thing is really nasty and does not want to get unstuck) TPU

Result:

TPU

0.6 nozzle with 0.30 mm layer - PETG

PETG

Overhang Challenge

Web Site

Resin Printer Test

I also wanted to learn how to use the resin printer from the lab associated with the FabLab. Axel explained how to use it.

Unfortunately the printer does not wanted to print saying that the level of resin is insufficient. But in reality the level of the resin was where it was supposed to be... The resin was also expired... By one month...

So no resin printing for me.
(Yet)

Final project

The idea is to print a pin. This could technically also be made with subtractively but for that we would need a 5-axis CNC. Also it would permit (I think) to make the pin AND the electronic holder (that is missing in this print as I am not there yet) at the same time. (Flat surface will be modified to hold electronics)

So I printed my pin to test if it fits in the holes of my mdf plaque. It broke.

Broken Pin

I did not think things through when I did the GCode. The layer directions was made so it could brake easily.

Changed the direction and now it works.

Pin in a hole

But it is a little hard to take it out. I should try with PETG.

Pin

To be honest I did not feel any difference. Seems like it is to small to have a different feel.

Learning Outcome

I already knew how to use a printer and how to maintain a Prusa MK3S.

But I never printed in TPU yet. It seems wrong to put sticky paper on a printing bed.

Assignment Check

  • group assignment:
    • test the design rules for your 3D printer(s)
      • Done
  • individual assignment:
    • design and 3D print an object (small, few cm3, limited by printer time) that could not be made subtractively
      • Done
    • 3D scan an object (and optionally print it)
      • Done