3D-Printed Magnet-Embedding
Courteney Reitz
Graduate 2021, Bachelor Interior Architecture & Furniture Design
What technique was this research based on?
I was curious about 3D printing and how to connect parts and shapes without using standard types of joinery or glue. I was also inspired by a game book that used magnets as its method of closing and holding the parts together, thus magnets became an integral part of the research exploration. I used the technique of embedding and programming pauses into my prints, which allowed me to insert magnets. I would say that the technique became a result of the research, as I really wanted the ‘connection’ to be hidden and provide a ‘surprise element’ when the 3D parts joined to one another.
If anything went wrong along the way, what did you do?
Many things went wrong. The first problem was the print bed: the initial embedded magnet test was on a glass print bed. Needless to say, the magnets jumped out and latched onto the hot-end/extrusion nozzle of the printer. Pro tip: use a metal print bed! The second difficulty was finding the correct tolerance for the gap where the magnet needed to be placed. When printing with various plastics, they expand and retract, and magnets (metal) are conductors of heat, so this all needed to be considered. The other important tolerance was the thickness and infill percentage used around the magnet. Magnets of different sizes have different strengths, thus you have to determine the strength that you want after the magnet has been embedded. This is also important to remember when using really strong magnets, as they can also do what I mentioned in the first problem above, so what I had to do was ‘fake it’ and go against what I wanted to do and use a small amount of super glue to keep the magnet from jumping out of its gap for the embedding. Another important thing that I discovered when printing multiple pieces on the same print bed was to keep in mind the distance between them. If too close, the magnets will attract to one another and pull the print off of the bed, meaning I would have to start the print again.
Materials:
PLA and PETG plastics/filaments (various colours), magnets
Tools / Techniques:
Prusa Slicers, with metal print bed and free software to slice your STL files. Within the Prusa Slicer program, you can use the ‘Print Mode’ function to program a ‘pause’ into the code. The same function allows you to add a ‘colour change’ or ‘custom code’ into the GCODE used for printing. For PLA and PETG, use the recommended print settings: PLA — nozzle = 215°C, bed = 60°C; PETG — nozzle = 240°C, bed = 85°C. For the infill pattern use the ‘grid’ or ‘aligned rectilinear’ and for the infill percentage, depending on the size of the object and magnet strength, between 5-8%.
Workshops:
KABK 3D Lab
KABK Metal
Steps:
Create your design in a 3D-modelling program (such as Rhinoceros). Remember to ‘cutout’ the gap for where magnet will need to be placed.
Export file as an STL document and open it in your slicing program. (A slicing program is used to convert your file into a GCODE (a combination of codes and instructions), which is the file type a 3D printer reads.)
Apply your settings in the slicer program, e.g. material type (this usually generates recommended temperatures, otherwise you can change them manually), infill pattern and percentage, any support structures that may be needed (place a support blocker where the magnet would be embedded, as you do not want the printer to print the support there — the magnet will provide support once placed inside), and your pause or colour change (important to note, is that it should be at the exact layer of the colour change or at the exact layer of the magnet gap top height — the magnet should not be sticking out when the print continues, otherwise the nozzle will collide with the magnet and get damaged). Then save it as a GCODE and place the SD Card/USB into the printer.
Start your print and watch it go! The print will pause as per your settings and then it is time to insert the magnet/s. Tip: place the magnet onto a pair of pliers (they will stick automatically), place the magnet into the gap and then gently pull the pliers away in a sort of sliding motion (BE VERY GENTLE AT THIS STEP — you do not want to move the print off of the print bed). Also keep in mind that if you are placing multiple magnets, it is best not to carry the new magnet over the one you have just placed, sometimes they pop out again and can move the print.
Before continuing the print, place a small amount of glue stick onto the magnet, this will help to give grip and better adhesion for the filament and the first layer above the magnet.
Remove the prints when they are finished and have fun!
Health and Safety Precautions:
When working with 3D printers in general, always remember that there are hot metal parts on the machine. Watch where you place your fingers and hands. If removing support from a design, wear protective glasses, as small parts can fly up into your eyes. Always be careful when working with magnets. Do not eat them and be careful if children are around. Also be aware of the strength of magnets, if strong enough, they can attract to one another with force and if a finger or body part gets between them, it can be very dangerous.
This recipe is part of Touching: A Research Method in Art and Design, an exhibition curated by architect and KABK tutor Laura van Santen, featuring the materials and research of students, tutors and workshop instructors from the KABK.
More information on the display, all samples and recipes can be found here.