Nitty gritty details required to make thousands of things
These last few weeks have been pretty busy, and we're proud to announce that the BlinkyTile is in production!
We'd like to take a moment to give a special thanks to our collaborators, Sam and Honghong, for all their help so far in making the BlinkyTile a reality.
The first thing we did was to find a printed circuit board (PCB) production company that could handle producing the BlinkyTile panels. As we've mentioned in previous updates, the BlinkyTile PCB is a little goofy compared to what most places normally produce. The biggest issues are the number of cutouts in the board, and the requirement that the entire thing be 100% functional. So why is that an issue?
Normally when a PCB is fabricated, it's actually made in a panel that contains a bunch of copies of the same circuit, to make it easier to handle a bunch of them at the same time. There's always a small chance that there might be a production error at some place in the panel (a bit of copper sticks to a trace and causes a short, etc), which might cause one of the individual boards not to work. Because they don't want to waste a panel with mostly working boards, though, they just write an X on the one that didn't work, and at the end of the process, that individual piece is discarded. That way, only the small part of the panel is scrap, and overall the yield can still be high.
Of course, for the BlinkyTile, the panel is the end product, so the whole thing has to be scrapped* if an individual piece doesn't work! It turns out that a lot of smaller volume PCB manufacturers (the ones we usually use for prototyping) have just ok process control that results in many of the panels having small errors. This works great for small prototypes, because it means they can make a lot of small designs quickly, however it's not suited for this project. To make the BlinkyTile, we're working with a larger factory that has automated equipment for the PCB production, which means they can expect a much lower defect rate, and the yield for producing BlinkyTile panels should be high enough to be acceptable.
*Note: actually we won't scrap them, but we won't send them out in kits either. We can use the working tiles from these incomplete panels for installation work!
Next, we met with our printed circuit board assembly (PCBA) partner to hand off the components for the controller production. These are the folks that take all of the components (processor, resistors and capacitors, connectors), and solder them to the PCB to make a completed circuit. We'd actually met with them a few months earlier, and were impressed with their operations. They mainly produce demonstration boards for large companies, and have a workflow that allows them to pay attention to issues that might happen in medium scale production. This is in contrast to really small shops, that might just make something quickly and cheaply, but don't have a stable process, or large shops, that require very controlled processes and test plans, but also pre-production test runs that might be as large as our total order.
Light diffuser production
Finally, we happy to announce that we've found an injection molding shop to work with us to produce the pyramidal diffuser tops. Our friend Nick helped to modify the design to make it ready for injection, which meant redesigning the model to have rounded edges, increasing the thickness to work with the injection molding process, and modifying the clip design to make them longer, so the plastic can absorb the flex while being inserted. The only issue is that it's going to take a week or two longer to finish the plastic parts, so they might need to ship separately. We'll be in touch soon with details on these!
So what's next?
So those are all the long lead time items. We're not out of the woods yet, though- there's a bunch of details left in the test rigs, instruction guide, firmware, and logistics. We are getting close though- look for a backer survey soon to confirm your shipping information!
Also, look for a workshop soon in a city near you- Honghong and Matt are doing a small tour of the US next month, and are looking to hold some holiday BlinkyTile workshops. We're confirmed for New York City, but we'd love to hold events in Detroit, San Francisco, and Las Vegas- if you know of a hacker or Makerspace near there that might be interested in a workshop, let us know!