Strap Spring Bar Measurement

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  • I can't seem to find measurements in the watch specifications. I'm planning to buy a handful of NATO straps, but I need to know what the spring bar measurement is in millimeters so I can source the spring and strap sizes appropriately. Here is the site I plan to source parts from:­cts/spring-bars?variant=504935013

    I don't yet have my watch so I can't get the measurements myself. Hoping someone could take the time to measure theirs and perhaps also get some attention to getting these specs added to the product's page or at least a link to these numbers from some drawing.

  • There's no spring bar on the watch, but rather a solid pin holding the strap in place (two pins actually, one on each side, of course). It is 29 mm long and has a diameter of 1.5 mm.

    The measurments between the two "taps" (I've actually no idea what to call them) on the watch where the strap attaches are as follows (see the disassembly video to see what I mean):
    Outer edges - 23 mm
    Inner edges - 12.7 mm

    Edit: If you want to use a standard strap and have access to a 3D-printer you might want to try something like this:­1

  • Thanks so much! Sounds like I'm going to have to wait on making an order for straps for the time being since none of the spring bars sold at are going to work. Its likely going to need some sort of 3D printed adapter to make it compatible with a NATO strap.

    If you have a moment can you measure the thinnest width of the strap? I'm buying a handful of 22 mm straps for a couple of Pebble Time Steel watches that I'm handing over to my kids when I receive the Bangle.js and I think maybe I should anticipate a one strap size fits both watches depending on the measurement you find.

  • The thinnest width of the strap (not counting the narrowing right at the end) is just over 24 mm (24.2), and (for completeness) right by the watch, at the base, it is 34 mm

  • Thanks! I'll try to do something with 24 mm then and perhaps failover if needed to 22 mm to make use of parts I'm getting for the Pebble. Either way probably would work, but 24 mm likely makes it less awkward with proportions.

    I haven't worked with anything other than PLA yet in 3D printing, but I don't think that's going to cut it for a custom adapter I would have to create to make this possible unless I integrate some metal bushing in there for strength where the spring bar would meet the plastic.

  • I haven't worked with anything other than PLA yet in 3D printing

    Try Polymaker’s Polymax - Feels like ABS, but is PLA­-abs-polymaker-polymax

  • I was thinking I'll try out a PETG based filament for this job since it has excellent mechanical strength, doesn't warp under ranging temps, has a much higher melting point that PLA or ABS so if I accidentally leave it in the car it has a better chance of coming out not warped, and its food safe so I shouldn't worry much about constant contact with skin and leaching chemicals. Thanks for the tip though.

  • Here are pictures for the measurements of the lug and the pin.
    Does someone have a Suunto core adapter lying around ?
    From what I've seen I think should also fit on the Bangle.

    5 Attachments

    • Abstand 1.jpg
    • Abstand 2.jpg
    • Stab-Dicke.jpg
    • Stab-Laenge.jpg
    • Suunto Core Adapter Example.png
  • @user110971 your numbers match those that @Johan_O posted so thanks for the confirmation :)

    Interesting adapter you found there. I'd like to know if the Suunto core adapter works as well, although I think I'll stick with a custom printed solution as I'm not digging those screws which I can see easily falling out.

  • Wow, great spot on those Suunto core adapters! There seem to be a few options on eBay so it'd be great if they fitted properly.

  • So lets get a pair and design a new adapter to fit on Bangle.js

    Or just two pairs of tube screws like this:­be-conversion-kit-for-fitting-leather-st­raps-to-tag-heuer-s-el-gents-models-as-l­isted-below.html

  • I'd like to see if the existing push pin can be re-used for the printed part, but I can see it being handy to use one of those tube screws if the pin doesn't make a tight fit or is too tight.

    Unfortunately, I still don't have my watch to get measurements as it seems that it may be stuck in the shipping center Chicago USPS due to this Coronavirus issue. Rather than endlessly asking peeps to take measurements can I ask @Gordon if there's a CAD or 3D model available for public reference to make 3D printing stuffs easier to springboard from?

    I didn't think there would be interest in this so I'm happy to have drawn a small crowd :)

  • I'm looking for a good solution for a custom made strap as well (as I'm sure there are many others that might be looking for ways to use the strap of their choice), so this is an interesting subject...

    Don't know if @Gordon has any CAD or model files for you, but from what I understand we're using this hardware, so maybe you could find something for that if you look around (probably not though, but maybe worth a shot).

  • I'm afraid there's no CAD model available because it's an off the shelf device, so I guess we'd actually have to make one...

    Even a proper schematic with measurements would be handy though I guess.

  • @Johan_O thanks for the link. Looks like the same hardware. Something strange happened when I followed that link on my PC. Malwarebytes kicked in to let me know something:

    Website blocked due to a suspicious top level domain (TLD)

    Website blocked: Malwarebytes Browser Guard blocked this
    website because it may contain scam activity.

    @Gordon As soon as my watch arrives I'll start working on building a model unless someone beats me to it.

  • Got my watch in the mail yesterday! I'm gonna start creating an exterior watch core model with AutoDesk Fusion 360 which is free for personal use:­n-360-for-hobbyists Make sure you meet the requirements if you plan to use the free personal license. I'm a bit rusty with modeling software so this is going to take some time.

    In the future I may be building a 3D model generating lidar scanner turntable that could possibly be used to make this sort of work easier.

  • That would be awesome - thanks!

    Actually I hadn't considered this but potentially it'd be possible to 3D print custom watch cases :)

  • General Question: How would you get waterproof buttons inside a custom made watch housing. [sth. keeping me thinking for a couple of days ;) ]
    Maybe someone has a solution.

  • How would you get waterproof buttons inside a custom made watch housing


  • If you're 3D printing you could print the whole housing (or part of it) out of something rubbery that'd flex where the buttons are :)

  • Or you use small magnets and a hall sensor to read then you don't need to have any actual penetration of the watch core hull. I really wonder if the folks over at would be interested in partnering up for something custom in this area. Those guys over there at poly magnet are amazing! They can custom design magnets to achieve feats that normal magnets that we know today are not capable of! Check out this video to be amazed and get an idea of what I'm talking about:­ApQ

  • There are some really cool things you could do with magnets... That sounds like it could become really expensive, real quick though. :D

  • In my opinion the simplest solution would be a screwable/pushable/waterproof watch pusher. (like attachments)

    2 Attachments

    • Push Type Watch Pusher.png
    • Waterproof Pushable Watch Pusher.png
  • Wow, those look lovely. They'd give a really nice finish too

  • Just a note about the 'Suunto core adapter' @Matt was asking about.

    Mine arrived and it fits pretty well. It's about 1mm too wide so is a bit floppy, but it's not that bad. Definitely an easy way to get a custom strap on your watch anyway.

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Strap Spring Bar Measurement

Posted by Avatar for Sn3akyP3t3 @Sn3akyP3t3