Hand and power tools are cheap, reliable, and easily accessible. But their production is still done in large centralized factories. 3D printing technology and cheap, opensource electronics continue to improve bringing the decentralization of manufacturing one step closer.
We are experimenting with different designs to see how close current 3D printing technology can bring us to production-quality tools you can buy in the store. We're also experimenting to see what modifications we can make to store-bought tools to enhance and customize their use.
As we develop tools, we will list them below including a link to their page on Thingiverse.
Check out project logs if you're curious about how we developed them.
January 12, 2019 | ProgressTH The original 3D files for our 3D printed electric screwdriver depended on hot glue to keep pressure from the servo coupler and bit holder from transferring to the servo. The coupler was glued to one 608zz bearing. In theory, the bearing should have kept the coupler straight.
In practice, the coupler and bit created immense wobble to the point where it was difficult to get the screwdriver to line up with bolts we were trying to drive. Also, if the hot glue gives during use, any pressure put on the bit will transfer directly to the servo itself.
The solution was redesigning everything related to motion control:
The bearing housing was extended to fit two bearings;
The coupler and bit holder were integrated into a single piece and passes through both bearings before interfacing with the servo arm coupler;
The bit holder portion of the new piece rests on the bearings. No matter how hard you push, pressure cannot be transferred onto the servo.
Now, the only wobble is from the screwdriver fitting slightly loose in the bit holder and this is barely noticeable. It is still not perfect, but at least for this application, it works well enough.
Getting perfect motion control out of a 3D printed power tool is important. For an electric screwdriver, a little wobble is acceptable. For anything moving at higher RPM's, wobble is unacceptable, not to mention dangerous.
The diagram above doesn't show the original coupler and bit holder. It shows the first try at designing a bit holder that physically rests on the bearing instead of depending on hot glue to keep pressure off the servo. It had too much wobble, prompting the two-bearing design.
December 12, 2018 | ProgressTH We tried to make the screwdriver cordless. With 4 AA batteries, the 6v output sped up the servo nicely and allowed us to use it wherever we went.
But then again, we were only driving M4-M3 bolts at our workbench and the added bulk of the new cordless design negated the comfortable and small profile of the original design.
The above picture shows the cordless version at the top. Just below it is our corded version which we've chosen to use day-to-day. Below that are two earlier prototypes.
Maybe there are better batteries that we can use, but in the mean time, we're using this buck step down power supply (pictured above) to take a 9v wall adapter and stepping it down to 6v. The 5v wall adapter was turning the servo too slow and the data sheet for the servo says it can take a little over 6v.
The power supply fits easily into the handle of our corded version.
November 29, 2018 | ProgressTH Here is our first entry to our 3D printed opensource tool project — a 3D printed, 5v powered, 9g servo driven, thumb joystick actuated, Arduino Nano controlled electric screwdriver.
All the files are available here on Thingiverse. It includes a video showing the screwdriver in action and a quick look inside with a few comments on its function.
It began as an experiment out of curiosity to see if spare parts laying around could be used to turn a set of jeweler's screwdrivers. We had some 400-500 M3 bolts to drive for an upcoming project and thought it would be nice if we could quickly hack together a solution. And we did!
Yes, we could have taken an hour to go to the store and buy an electric screwdriver, or ordered one online since we had about a week before our big project would begin. but in just one day we designed, printed, and had a functioning prototype that was up to the task. In 2 more days, we had a final prototype, the one you see in the picture above.
In this picture (just above) you can see the design process from linking up the electronics and the screwdriver to the servo, to several handle designs with the top being the final outcome.
The thing we like about making our own tools is that we can make them exactly as we want, with the exact feel, look, and function. We also learn a lot in the process.
What's next? We're not really sure. We like this screwdriver so much we're interested in improving it further (speeding up the servo, using a different type of motor altogether, making it cordless, etc.). We're also pretty pleased with what 3D printing enabled us to do here where we'll experiment with some other basic power tools and tool modifications.