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A 0.80mm thin flexible wristwatch with an E Ink display housed in a single piece of stainless steel.
A 0.80mm thin flexible wristwatch with an E Ink display housed in a single piece of stainless steel.
7,658 backers pledged $1,026,292 to help bring this project to life.

Our E Ink Circuits Have Arrived!


First of all, we’d like to thank E Ink for all their hard work to date. We’re excited to announce we received the first 150 fully integrated circuits a week ago! A major milestone to completing delivery of these watches to our backers.

We’ve spent all week testing these circuits and everything is looking good. All the segments are behaving correctly and the circuitry is behaving as expected. We’ll continue testing these for a few more days to make sure everything is okay before we pull the trigger on the final production line. Flextronics is advising us on top-priority testing procedures. (A looong list of tests for at least 75 of these units means gallons of Red Bull and coffee are in our near future.) It’s an important and nerve-wracking activity: we have to be sure the circuits are perfect, as there’s no going back from this point.

We’ve fabricated a programming head to run these tests while Flextronics works on the mass-production solution for programming all the watches.

Mechanically Testing the Circuit 

The circuits passed our first test with flying colors: they’re dimensionally accurate! Approximately 0.425mm maximum thickness. The perfect size for the world’s thinnest watch.

In parallel to all the electrical tests we’re performing on the circuits, we’re also doing mechanical tests on them. We’re making sure the circuits still work when bent and applied onto the band, and we’re confirming that when we do trim the circuits to different sizes, it doesn’t damage any of the components.

In the image below, you’ll see a flexible circuit trimmed to the smallest size with a newly formed “small” band in the background.

Base Station Development 

We’re well into tooling and assembly-strategy reviews with Flextronics. We also have initial injection-mold tooling drawings. It’s been a challenging month with many rounds of revisions to ensure a really robust enclosure.

But, after all that work, we’re poised to meet the final tooling-release deadline we’ve set for ourselves: about a week from now. (A small victory.)

After testing the last iteration of the base station over an extended period of time, it became clear that we needed to refine the mechanism to get a good, reliable connection to the watch itself while not damaging the connector. We now have that final, refined, mechanical architecture that gives great electrical contact to the watch when charging and changing the time.

The latest iteration of the base station has a completely custom mechanism inside. When the watch is inserted, a small plastic part rotates into place to hit the charging contacts accurately. Because the connectors are rotated into place, there’s no risk of scraping past the connectors and damaging them. We’ve managed to do this while still retaining the small package (about 20% the size of the original charger).

Here’s an image of the initial injection-mold tool drawings. This is for the main part of the Base Station—it’s a complicated tool. :)

This part is injection molded first, then the tool swings out to another platen to begin the rubber overmolding process. The purple, blue, and orange sections show parts of the tool that slide to mold button details, USB details, and a window for CE and FCC labelling.

All the plastic parts have to be analyzed for plastic mold flow. Here’s an example of one type of analysis for the top plastic part:

This Coming Month of Activities 

We’ll be spending all our waking hours this month getting the above parts fabricated and assembled so that we can embark on certification testing.

Making all the parts, assembling them, and testing them should take about 2-3 weeks, which leads us into accelerated wear, thermal, moisture, ESD, CE, FCC testing, which takes another 3-4 weeks. We have printed circuit boards for the Base Station arriving this week and next, so we’re on plan for this build phase. It’s important we pass all these tests so we can ship worldwide and we are confident our product will perform well.

This month is going to be a busy one… :)

On a Less Technical Note: CST is Now Our Full-Time Job 

On a recent call with E Ink, the team was surprised to discover we’re doing CST full time now: all day, every day. And it struck us that even with all the updates, we hadn’t told any of you either! Our bad.

We left our jobs at IDEO about 6 months ago. We had to: the design and development of the CST-01 is requiring our full attention. We want you all to know that we’re fully committed to this and only this right now. Our job is to deliver high-quality watches. Period.

Okay, that’s about all for now. Thanks again to all our backers and thanks for reading this mini update..

We’re expecting more parts of the puzzle to arrive over the next few weeks, and we’ll share pictures when we have them, in the style of mini updates like this one.

Dave, Jerry & the CST team


We’ve been getting a lot of similar questions, so we’ll be publishing a FAQ at the bottom of our updates in order to answer the majority of questions we receive.

Will you still be shipping in September? No. Our current schedule shows we’ll start to ship in December.

What order will you be sending out watches? Can I get mine first? Rewards will be sent out in the order they were received. This is the only fair way to schedule it. We’re doing everything we can to get them out as soon as possible.

Has the survey gone out yet? Not yet. In the survey, you’ll be able to select your size(s), color(s), and submit your shipping information. We’re only allowed to send one survey, and as these types of data change every once in a while, we’re waiting until we absolutely need this info before sending you the survey. We’ill do everything we can to make sure you don't miss it, and we’ill post in the comments and issue an update when it does go out. If you’re concerned that you missed the survey, please look through the updates.

I would like to select my size, I am a... You’ll be able to do this in the survey that will be sent out when we need this information. The survey has not been sent out yet.

I would like to change my color to... See above

How can I change my shipping address? See above

Using the size chart, my wrist is just barely inside of (one size) and barely outside of (another size), which size do I choose? Using the size chart, you should choose the size where the band is inside the "size range" square (not outside). There’s no overlap in the sizing chart, and no space between sizes, so you should be inside of one of the areas. If it's really right on the line, and you don't know what to choose, we recommend the smaller size since the bands can be spread out slightly to accommodate larger wrists easier than they can be made smaller.

I'm a distributor/reseller/vlogger and would like a sample for… Production samples are not ready yet. The DVUs we do have are not final parts and are not ready for evaluation by suppliers or testers.

Where can I buy one? / I just found out about this Kickstarter and still want to pre-order one. / I would like to order additional colors. We’re still in the process of producing the CST-01, so they’re not shipping currently. If you’re interested in getting your name on the list for when we do ship, you can pre-order watches on our site: Orders will be fulfilled in the order they were placed. Thanks for the interest!

I see that there’s one watch left at the $99 level, how do I get that one? The Kickstarter campaign has ended. That statement is a bug in the Kickstarter system that we’ve requested to have removed. We’ve been told that removing this statement is not possible, so you’ill just need to take our word that the campaign is over and there are no "early bird" rewards left. However, we’re still taking pre-orders on our site:


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    1. Carl Forde on November 18, 2013

      Solar could be done two ways. On the watch, or on the base station. Adding panels to the watch would entail a /major/ redesign. The only function of the base station then would be to set the time. So why have the base station, just add that feature to the watch too. Yeah, a major redesign. Adding panels and rechargeable battery to the base station, and removing the cord would be comparatively easy, but I suspect we are too late in the process to see that for the initial shipments. Maybe a feature for future watches? Base stations are sold separately, you would be able to order a solar version if you wanted it.

    2. Michael Gimon on November 1, 2013

      i would pay extra for a solar version.

    3. Garrett Schorsch on October 29, 2013

      It looks amazing! Thanks guys.

    4. Ty Martin on October 28, 2013

      Thanks for the update guys. Really cool to see what it takes to build something "right."

      Agree with the other couple suggestions here: solar would be a-mazing and exactly the kind of feature to take this piece to the next level. As one who travels a lot (and who doesn't these days right?), it would mean one less thing to worry about.

    5. Missing avatar

      Philipp Stöß on October 27, 2013


      Would be really a super idea and would also wait a little.

      How Währe with a vote?

      Thank you Philip

    6. Darklord on October 26, 2013

      Awesome update, can;t wait for mine! :D

    7. Tara Martin Dale on October 26, 2013

      So excited for this project, thanks for the update!

    8. Missing avatar

      dean salomon on October 26, 2013

      Hi guys. Nice progress and getting closer...
      I do have a question/ suggestion: the much smaller now base station. If the watch takes so little energy to fill and lasts a while why no put a small solar panel on the back and charging battery and let us fell it from the sun a few days and the watch also that way. I know it's more green and delay another little bit but it will make it a travel watch for travel and doesn't matter for 110-220.
      Just a thought....

    9. Lorane Hudson on October 25, 2013

      I love your updates so much! Very informative and professional and just often enough to keep me from worrying. Delays aren't too bad when there is good communication and you guys have done great in that area. Really excited on the progress you have made and even more so on the improvements. I know this will probably be the nicest watch I've ever owned and can't wait to see it once it's finished. Keep up the great work! :D

    10. Missing avatar

      Benjamin Tait on October 25, 2013

      Gorgeous watch! Definitely can't wait for this one. Is there any possibility to rotate the numbers to be vertically aligned as that would read better across the wristband? Or have it as a setting to change the orientation of the numbers on the display? Just a thought

    11. Joe Walnes and Alex Lukashevich on October 25, 2013

      Excellent update! Really impressed by the engineering going into this!

    12. Missing avatar

      OliVer Fronk on October 25, 2013

      Guys u'r doing a great job. Guess you didn't expect that investment of human ressources but u'r still on the way. Respect. I also backed Pabble but they had big problems with shipments to germany... After 9 month of waiting I cancelled my support. But you are responding and I'm feeling safe. So take your time to develop and produce the RIGHT product. I trust in you!
      Kindest regards
      Oliver Fronk

    13. Margie Hackett on October 25, 2013

      I have been trying to cancel my pledge, no one is responding.
      Please contact me.
      Margie L. Hackett

    14. jimmy traettino on October 25, 2013

      when do i get the watch?

    15. Greg Roxburgh on October 25, 2013

      The best things come to those that wait. Keep it up guys :)

    16. Caleb Chamberlain on October 25, 2013

      Fantastic! These are looking great.

      I made the $129 pledge but for some reason my reward tier is set at $1 (which means I won't receive a watch when they are finished). Can you fix this?