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

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  • Wow, this is really cool!

    My son just recently accidentally banged up my bangle on the playground, so I thought it would be nice to have something to ruggedize the watch before it's too late.

    Since I don't have the same dedication as halemmerich to transplant the whole watch, I though about creating an outer shell for the current watch housing that reduces risk of the screen getting deep scratches or cracks.

    @halemmerich, from your experience, do you think that a shell with 1mm thickness around the outer borders of the watch would work? Something that could then be attached to the original housing using some glue, maybe?

    (That reminds me, I should also share some of my original designs for a charging pedestal that I 3d printed for myself!)

  • I should add that we do sell https://shop.espruino.com/banglejs2-coveĀ­r if you want something easy - but those are silicone, so might not be as protective as something solid

  • Thanks for the hint, @Gordon!

    I'm not entirely sure (and I can't really tell from the pictures), but to me it looks like the silicone does not really extend above the glass that much and that's what I'd like to better protect.

    If anyone has a better picture with the silicone cover on from the side, I'd be much obliged!

  • I converted the Step file of the banglejs housing (thanks @Gordon) to an obj that which I imported to fusion 360 to create the metal cover rim that fits around the BJS2.

    I just finished printing the plastic sample and I'm quite happy with the result, even though the white certainly ruins the look, but that's just the filament I currently have loaded into my 3d printer... So I also did a render in fusion 360 so I could have a better idea what the metal part would look like.

    Since @halemmerich mentioned that the part tolerances are good but might be a tiny bit off, I'll just order multiple pieces at 95%, 97%, 100%, 102% and 105% scale and check which works best. (For cost reduction, I'll try to order a single item that I have to saw apart, let's see if that works)

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    • cover.JPG
  • I have given the border around the display an additional 0,5mm in x and y direction in my drawing and it fits loosely in the case. I did not try to measure that with a feeler gauge (lost those somewhere) but there seem to be about 0,3mm space all around the display so I would suspect you can be closer around 100% size for your tries. Maybe 101% and 102% to leave a bit of room for glue if you have your current CAD at a perfect fit. Since the turnaround is just about one week (JLCPCB->Germany) and postage is not that bad a second try is not a big problem.

    If this fits well and works nicely with Bluetooth and GPS you could think about removing the original watchband holders and modeling them on the case. There are some people having broken those off and having them in steel is probably more rugged.

  • My attempt at having them print a connected part to try multiple sizes failes, as connected parts are not allowed for metal prints. Anyway, I now ordered a single one: I remeasured my actual watch with a caliper and added 0.3mm on all sides. Fingers crossed it fits!

    @halemmerich I really like your idea of adding watchband holders to the metal part. This would require people to remove the original holders, but could also be a much cleaner design. If this fits nicely I'll add the holders to the CAD model and provide it for everybody to print/order themselves. It could also be a very simple and cheap way to repair broken BJS2s

  • That's a really elegant solution to the ruggedness problem. If it weren't for USB-C and a bigger battery that I want I would definitely go down your route. Doing the full transplant is very time consuming and the risk of killing the donor bangle is considerable.

  • I finally received the 3d printed metal part and it fits perfectly, a slight press fit. With a drop of glue it should hold on fine for day to day usage.

    If the wrist band holders would also be made of metal and part of the cover, there would be no need at all for any glue, since the watch would stay sandwiched in place between wrist and watch-cover.

    Anyway, I'm trying to figure out if I leave the finish as is, or if I should try to brush the metal using a Dremel bit on my small CNC... I don't even know if there is any pretty finishing to be achieved with the printed metal parts. Please tell me if anyone has any ideas

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  • I sanded it down a bit and it looks much nicer now. I got to keep sanding, bit I only have 120 grit paper right now. it still has the look as if Tony stark made this in a cave... But also maybe that is exactly how a banglejs2 is supposed to look

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    • Screenshot_20240710-230823~2.png
  • Wow, that's awesome! I guess if you just ground off the Bangle's existing strap mount lugs then you could do them as part of the print without bulking it up too much?

  • The stainless is relatively soft and thus sensitive to scratches. I think the somewhat rustic optics you have now should withstand use pretty well. Could be nice combined with maybe band from wooden elements.

    How is GPS, BT and touch for you?

  • i cant buy on your site because no shipping to my country.
    how can i buy this ?sale on aliexpress or adafruit site (can send only to coumtry but i prefer aliexpress will much more cheap)

  • Haven't tried gps yet, but touch and bluetooth work flawlessly thus far. IDK if there's a Bluetooth benchmark of sorts that I could use to get any measurements instead of anecdata.

    I'll try and order a new version with thinner outer walls and als wrist band holders.

    All in all I am very happy with the outcome. It doesn't only make the watch more rugged, but I really like the style (and I even like the considerable weight it adds... It feels more "valuable")

    Anyway, I'm on the phone now, but I'll provide STLs for anybody who want to order some covers themselves soon

  • Hi I would like to order those could you upload the STLs?

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

Posted by Avatar for halemmerich @halemmerich