Piston holder for coffee grinder

After years of coffee grains all over the place by my coffee grinder. I did make a special holder for the piston.

Like the coffee machine you place 1/8 turn of the left and higher it into de machine, then turn it for 1/8. And the piston is secured in the holder.

The internal funnel ensures that the ground coffee ends up neatly in the piston. After grinding, remove the piston in reverse order. With this holder, the coffee grinder also makes less noise.

The holder consists of two parts that are attached to each other with three M3 bolts. In the top part there is an M3 thread, possibly the bottom part still needs to be drilled with an M3 drill. These bolts have a tapered flat head, the head protrudes a bit, about half a millimeter. This was done on purpose for the lid.

I made a lid for this, which contains three small magnets, recessed in the lid. This way the heads of the bolts fall precisely into these holes. The lid is self-centering due to the magnets. The magnets hold the lid securely in place.

I attached the holder to the coffee grinder with double-sided tape (Tesa Powerbond Ultra Strong).

These magnets are neodymium magnets 6mm diameter - 2mm thick - N50 strength.