Just received my coffee grinder bit and it works great. I use it with a JavaPresse Conical Burr Mill and the
Black & Decker AS6NG Alkaline Cordless Screwdriver (both purchased on Amazon). I only grind espresso, so it does take longer to grind, but now the electric screwdriver does the work. This electric screwdriver has very good torque and doesn't get stuck when grinding. I find it works best if I hold the screwdriver low near the working end (the end with the bit) and use my index finger to press the button. Very cool that the grinder bit is 3d printed. Thanks for making this product.