When reducing the grind size on Niche Zero, you need to run the motor a bit after each small turn of the dial to get rid of the coffee stuck between the burrs. Normally you have to close the lid every time, which can be quite annoying if you change the grind size between drip and espresso often.  

You can use this thing to permanently engage the small safety switch, so the motor can spin even with the lid open (when the main switch is on). It would be easy to solder the connection permanently, but I wanted something non-intrusive. 

I believe that with the NFC disk there's very little chance of sticking your fingers into the runnig grinder, but use at your own risk!

The installation is easy and should only take few minutes. Just remove the burrs (same as for cleaning), then unscrew the 4 screws holding the upper casing and the shoot (you'll need a 2.5mm hex screwdriver). Clip the printed latch on the switch and put everything back together. 

After a few design iterations this clips onto my switch very nicely, but I'm also including a step file if you need to move things a bit. 

Print on the side with supports. I used PETG, but PLA will likely work fine.