This is drilled thru both parts for the all thread and 2 nuts. I had to redrill the hole in the rack to 5/64".

The sets of 3 are just glued together with E6000 and glued to the back wall.

The hex part is screwed together with the bottom one.
The Allen wrench is a 2mm.

I drilled the 7 holes with a #60 drill, the shape around it is an 1/8" letter 'U' metal stamp the other is a #1 stamp

The tall post has a 1/4"ball bearing glued in with E6000
This part is held in with E6000 and I lightly mushroom the bottom edge

To make these i bent 7pcs of thin wire to shape and drilled 14 hole and just glued them in

These are the mounting posts the brass pc is a threaded insert and takes a m2 x .4 screw to attach it to the base. It fits inside the aluminum pc.

Kyle in N/W Indiana I have built 4 of the MSE droids. I made the polished aluminum and a clear one just because I could my 3rd one has a color changing paint and spikes where the screws are. I did the last one in alll black for a friend to haul his costume tote.