(Maybe) Building a new case for Bangle.js 2

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  • I wanted to have a go at FreeCAD and thought designing a case for the bangle would be nice to try out modeling something to actually build for the first time :)


    1. USB-C for charging
    2. Buildable by me
    3. Not a lot thicker than the original case
    4. Rugged (primarily better screen protection)
    5. Screw on back.
    6. Maybe even waterproof? (Found waterproof USB-C ports on ebay)
    7. Keep HRM


    1. Try making space for a bigger battery (36x25x4 330mAh might fit with about a millimeter more thickness)
    2. Simplify band mounting (just loops for textile straps maybe)
    3. Solution for mounting internal components without to much glue
    4. Find out if I can actually build the thing
    5. Find out if the HRM can be removed from the original case without being destroyed
    6. Refine the hardware mockups for better internal space representation

    Has somebody attempted something like this? I am sure this will take some iterations and probably fail in the end but no way of knowing without trying, eh?

    I have an old manual proxxon desktop mill that can do about 0.1mm precision and some other tools and want to do this in aluminium.

    I'll attach the FreeCAD file but be assured that it probably is not well done as I do not have experience with it or CAD at all.

    5 Attachments

  • Would be fun to get updates on the project if you go forward with it 🙂

  • Sounds like a neat idea!

  • Tried the first few cuts. Went better than expected :)

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    • RRvdBI9uRPWn2gvlxVCufQ.jpg
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  • Proper engineering stuff, impressive.

  • Hello,

    Interesting, on my watch one of the four holes for the batch is broken, so perhaps I will build your new case as well.


  • Thanks :) I cut down the top case a bit to get it closer the final dimensions and started carving out a bottom plate with material left for mounting the board.

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  • Hello @halemmerich,

    have you made a bluetooth test with the bangle inside the aluminium Case?


  • Not yet, but wrapping it in aluminium foil showed that it could work. Otherwise no way to tell how it will pan out with this dark magic RF stuff before I can actually close the case and screw it down 😉
    If there are problems I can always cut some slots into the case and fill them with epoxy to try to get it to work.

  • Some more changes on aluminium and CAD sides... Actually a bit of matching drawing to reality :)

    4 Attachments

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  • Wow, that's really starting to take shape now!

  • The overall shape is done (for now) and brushed over once just to see how it can look and before doing more I will have to wait on ordered M2 screws and a matching tap to hold it together.
    I still need to find a solution for getting the button PCB attached and try out if my chosen method of getting a button in there will work at all. I think this will need one more build anyway, so this one is dedicated to experiments :)

    5 Attachments

    • Js1xsoegQh65XXebxbBT3A_5bc992fe15f7c4befe07d5902b2be0dbde023258.jpg
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(Maybe) Building a new case for Bangle.js 2

Posted by Avatar for halemmerich @halemmerich