You’ll notice on the packaging that we advertise Assembled in USA (Custer, WI). We’d love to say Made in USA, but for electronics, that’s just about impossible. We have our rolling ball sensors coming from Taiwan, the Bluetooth module is made in China, and our bare circuit boards are from China, and we have no control over that. The most significant parts of our product, and we couldn’t find US manufacturers of them that were anywhere near our budget. With Assembled in USA, though, we have a little more freedom.
So how do we make BlueTipz in Wisconsin?
Component sourcing and logistics is a challenging problem. We have to worry about lead time, which is how long it takes from when we order a part to when we receive it. Some of our critical components have long lead times of up to two months, so we have to order them a long time before we need them. Other products aren’t available in the quantities we need, so we have to source them from multiple locations. And others are custom made for us, so we have to give them specs and pay them in advance. Handling logistics alone is a struggle, and shipping costs go up quickly, which is why it’s best to order in large quantities, so we don’t have to do it that frequently.
First in the list of parts is the plastic enclosure. To do that we went with Wadal Plastics, out of Medford, WI. They worked with a Chinese company to build the mold, which was then shipped to Wadal. Wadal had to modify the mold a bit, and experimented with a few different procedures for doing the molding before we came to something that would work well and snap firmly.
Here’s what one of our mold looks like:
The mold clamps open and shut a couple times a minute, each time squirting hot plastic into the part, letting it cool briefly, opening so that a robotic arm can remove the parts, and then repeating the process. 5000 parts can be done in just a couple days. They also did pad printing, putting the white design on the front. From Wadal we ended up with 5000 fronts, 5000 backs, and 5000 tops, all in boxes.
The plastics are just one of the components we get in big boxes. This is what 20,000 screws looks like:
5000 Lithium batteries made for a REALLY heavy box, too.
And here are the first 5000 circuit boards, unpopulated, in panels of 8:
So now we have all our components, and they are completely unassembled.
PCBA (populating the circuit board)
Next we have to put all the components onto the circuit board and solder them down. We could have gone to China to do this, but on such a tight timeline, going over there to source all the components, work on their assembly line, and make sure that quality stayed high, and then shipping everything back would have been extremely challenging. We could also have gone to a US PCBA (printed circuit board assembly) factory and had them do the circuit boards for us, but they ended up being a lot more expensive than we could afford, and had a longer lead time than we could work with.
We are instead manufacturing them ourselves. This gives us complete control over quality, we manufacture only as many as we need and ship them out the next day, and we save a lot of cost. To do that, we had to develop our own tools and set up processes that ensured consistency and quality. For example, we have a rig that makes sure that every LED sticks out the same amount. We have a toaster oven that we modified for doing the surface mount soldering. And we have a custom programmer that puts the software onto every BlueTipz device.
The guys in the photos are contractors we hired to do the assembly. When they’re not in college or working at Culver’s, they’re building BlueTipz. This has been an extremely valuable experience for all of us because they are able to produce a good quantity at a reasonable price, we can monitor quality quickly and easily because they are local, and they are building their resume and learning about the manufacturing and engineering process. We usually sit down with them at least once a week to talk about engineering and how everything works in the real world.
Placing components by hand. The band-aid was not a workplace injury.
Soldering the through-hole components using a custom rig for placement.
After the boards are finished mechanically, we need to program them with the right firmware. We developed a programmer to do this, which allows us to quickly upload the firmware and test the devices. We wrote a separate article on programming just the firmware.
Programming. We just press the board onto the interface and it starts on its own. Programming takes about 5 seconds.
Once we finish the circuit boards, it comes time for assembly. This is done around a kitchen table or coffee table, sometimes with a beer and a tv show. The PCBs are placed inside the enclosure, which is then screwed together. We test every device to make sure it alerts our phone, then put it in the packaging and seal the package. Sadly, we have no photos of this process, but it shouldn’t be hard to imagine.
There’s a lot of detail that we glossed over, but we can’t give away all our secrets. What we wanted to show was how we are able to scale from low volume prototype production up to mid-volume consumer level production with high quality, low investment, and a process that can easily be modified.