A box where the lid arms clamp down to hold it in place when the knob is turned.

To build the clamp box you will need to print one of the base options (regular, extra tall, or just a ring), the lid, knob, and 6 clamp arms.

To clean up the parts start by taking a bit of 3mm filament and run it along the grooves in the knob. If it sticks at any point, take a knife and widen the slot. The next clearance to check if take the arms and run them along the slots in the lid.

Next, insert a bit of 3mm filament into the holes in each of the clamp arms and trim it to be about 4mm from the surface.

Now take the knob and lid pieces and line up the axle bit on the knob with the hole in the center of the lid on the side with the slots. Turn it clockwise until the end of the slots in the knob line up with the slots in the lid.

Take the clamp arms you made earlier and push them into the slots. The 3mm filament should fit in the knob slots.

When you put the lid on the base there are bumps in the lid that line up with holes in the base, they should fall into place fairly easily. To lock the lid in place turn the knob clockwise until it stops.