Create a magnetic rubix cube like this one, but 3D print it instead! This works only on FDM/FFF printers because they allow you to pause on a layer, so you can drop in a magnet, then carry one printing over the top to encapsulate it within the cube!
See the cube in action
Overview and Background
Why is this useful?
This is a demonstration to show how components like magnets, nuts and bolts can be dropped in mid print to improve your components. For example you can embed captive nuts that never escape or magnets for alignment in jigs and fixtures.
How does it work?
Take a look at the GIF below. It shows where to pause your print to drop in each magnet for the central cube, which has 6 magnets. You will need to pause the print 3 times at the top of the cavities.
- Slice the cubes in your software and take a look at the number of the last layer before each cavity is filled in. This is the layer you tell the printer to pause on.
- Once you drop the magnet into the cavity, ensure it does not stick up above the surface of the last layer
- Resume the print so the magnet gets covered over on the next layer
- Do the same of the tops of the other cavities until you put all magnets in place
Lesson Plan and Activity
What do I need?
- Access to a FDM / FFF 3D printer which allows you to pause the printer on a set layer height
- QTY x 12 12mm dia x 3mm thick neodymium magnets like these
- QTY x 96 6mm dia x 3mm thick neodymium magnets like these
Wow there are a lot of files, which do I use?
There are 3 slightly different sets of cubes depending on how thin of a contour your 3D printer can produce.
For each rubix cube you will need:
- x1 master_cube_XX
- x6 side_mid_XX
- x12 side_top_XX
- x8 corner_XX
How many magnets do each cube contain?
- x1 master_cube_XX = 6 magnets (all 12mm diameter)
- x6 side_mid_XX = 5 magnets (x1 12mm dia, x4 6mm dia)
- x12 side_top_XX = 4 magnets (all 6mm dia magnets)
- x8 corner_XX = 3 magnets (all 6mm dia magnets)
You need to print using a single XX offset. For example if you printer can produce a 0.3mm contour, or single line of filament, use the 03 numbered files. If you have a tiny nozzle diameter you might be able to print 0.1mm contour widths, this is preferable as it reduces the distance the magnets are from each other, which maximises the attraction forces. With that being said these small magnets are STRONG so it will still work fine with the larger offsets.
- Think about the polarity of the magnets and mark the positive and negative on each one. This takes time but is worth it.
- You can print all the cubes in a single batch/print, but I would do a few at a time... if you get the magnets the wrong way around it can be frustrating.
- Be careful when pushing in your magnets, you don't want to move your print bed or damage your printer! The magnets should drop in nicely without force.
- If your print bed can relocate in exactly the same place after it's removed, you might be able to do this mid print to push the magnets in more easily.