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    Rob's Tinkercad Classroom: Magnetic!

    Rob Morrill
    Published on - September 16, 2021 by Rob Morrill

    Inspiration

    Creating a magnet is a great project in either the 3D editor or Codeblocks. Students can be inventive and utilize valuable design skills while making something that is quick to print and functional. 

    The designs might go home to adorn refrigerators or magnetic boards, or they might stay on campus to hold photos or notes in lockers. Extend the project into the realm of design thinking by having students ask faculty and staff about their functional needs and aesthetic preferences, then design custom items for their “clients.” 

    IMG_20210915_162546 (1)Here’s a design made for a teacher so she can easily let her students know if they get to go to their library that day or not. This Codeblocks design has the stars rotate 0-80 degrees randomly. 

    You can buy plain magnets or ones with sticky backing already on them. Creating a hole for the magnet to nest in makes for both a more refined end product, and also for additional meaningful challenge in the process. The skill and attitude of designing prints meant to mesh with other parts can lead to ever more sophisticated projects. If you’re using plain magnets, experiment with which adhesive works best. Hot glue is easy but can become brittle and may not hold up over time. 

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    The 3D editor and Codeblocks can both be used with great success. 

     

    Option 1: Using the 3D design space

    Because the hole for the magnet is relatively small, many printers will be able to handle printing the designs hole-side-down without support. If you find you need to print with support, make sure you’ll be able to get it all out of the hole so the magnet will seat properly. Alternatively, you can design for printing upside down, but this will mean the design will need to be flat on top.

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    The underside of a locker-bound design. The printer was able to bridge the magnet's hole.

    In the 3D editor, try starting with a hole that is just half a millimeter or so greater than the diameter of the magnet. Students can confirm the magnet’s diameter with a pair of calipers. I like to make the hole slightly less deep than the magnet’s thickness so that it will stick out just a bit more than the 3D printed surface. 

    Next, you’ll want a shape on top of the hole that covers it completely, including being at least 1.5mm higher than the hole’s top. 

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    For this design, I just need to align the magnet-sized hole with the adornment. 

    From there, design away! Remind students to be mindful of the size though. Some magnets may not be able to handle the weight of a larger 3D print.

    This video shows how to make neat flower-like patterns using the align tool along with duplicate and repeat:

     

    Option 2: Using the Codeblocks design space

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    See a commented version of the code here.

    For an extra challenge, here's an alternative way to design magnets using Tinkercad Codeblocks.

    In Codeblocks, again start with a hole that is just half a millimeter or so greater than the diameter of the magnet. Students can confirm the magnet’s diameter with a pair of calipers. I like to make the hole slightly less deep than the magnet’s thickness so that it will stick out just a bit more than the 3D printed surface. 

    Use a Move block to raise the hole by half of whatever its height is. This will place the hole directly on the workplane. In my design, I’m moving it up the Z axis by 2.3, which if half of its 4.6 height.

    Next, add a shape that will serve to cover the magnet, and also move that shape up the Z axis by half its height. Here I’ve grouped the two shapes to make sure they interact as expected, but I’ll want to move that group block to the very bottom of my code later:

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    Next, code your main design. The trick is again to make sure all elements are resting right on the workplane so that things will print well. With some shapes, like a box or cylinder, this will be easy because you can just move them up the Z axis by half their height. The torus I used here was trickier because I scaled to get the height I needed. That meant I had to experiment with different values in the Move Z block.

     

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    Here, I’m closely inspecting the design from underneath to make sure the torus elements are exactly on the workplane. 

     

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    This design is similar to the flat flower, but I added an additional rotation in the X axis to create these upright petals. Here is the code with explanatory comments.

    These Codeblocks videos may help give you more ideas for using computational thinking to design magnets:

     

    I hope these resources are helpful. Students really enjoying making items for everyday use, so I think this project can be a winner while also providing so many opportunities for spatial reasoning, procedural problem-solving, and design. 

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    Here is my Tinkercad playlist of tutorial videos.

    If you enjoyed this column or tried this with students, please share your feedback and creations! What would you like to see more of? What works well? Feel free to contact me on Twitter or my website with your questions, suggestions, or ideas for future content.

     

    Tags: Inspiration