This week’s selection is the Palm Ratchet Knob by Printables contributor Shiura.
This highly practical design solves a common problem in workshops: the screwdriver or drill is too big. In such cases most workers normally rely on tiny manual tools that are often frustrating and challenging to operate in small niche spaces.
Enter the Palm Ratchet Knob, which should solve most of these scenarios with a unique design. Basically it’s a holder for screwdriver bits, but with a difference.
There are plenty of designs around that operate as a bit holder, and they are indeed useful. The difference with Shiura’s design is that it is also a ratchet.
The ingenious internal design of the mechanism allows it to rotate in one direction only, making it ideal for handling screws. Just turn it back and forth and it will power the screw forward — or backward.
That’s another fascinating innovation in this design: if you turn it over, the direction of rotation is reversed.
Here’s how it is designed internally to do all this:
Another innovation is that this mechanism is designed to be printed in place. That is, you print one object and it is automatically assembled. There’s nothing to do but use the ratchet once printed.
Shiura has provided two variations on the design, one with a 1/4 inch (6.35mm) hex socket for bits, and the other a 3.8 inch (9.5mm) square socket.
Shiura recommends heating your bits slightly to help insertion if the hole is too tight, which might happen on poorly tuned 3D printers. They also recommend using a bit of silicone lubricant to obtain “better ratchet feelings”.
There’s nothing better than ratchet feelings, and this item belongs in every 3D printer operator’s tool box.