Step 1: Mount the silicone bumpers
I suggest to apply 5 silicone bumpers beneath the base piece, so it will be more stable on the desk. You can use bumpers with a diameter up to 20mm.
Step 2: Assemble the PCB holders
The central part of the base consists of 4 sliding pieces arranged in a cross along which can be moved the anchoring blocks to firmly keep the printed circuit board in place. The assembly of the PCB holders to the base piece requires some wing nuts (5mm) and Hex bolts (5×12 mm). The PCB holders have two faces, one for straight sides, the other for the corners of a printed circuit board. You can choose the right face simply turning the holder.
Step 3: Assemble the crane arms
Fit the vertical crane arm into the hole of the rotating base support, then mount the horizontal crane arm using a wing nut (5mm) and a Hex bolt (5×12 mm).
Step 4: Install micro sprung probes
Step 5: Add optional parts
Now that you have almost finished your customized "PCB Workstation" perhaps you would like to add a magnifying glass, or a LED lamp, or even other accessories available from my original project "PCB Workstation with Articulated Arms" (http://www.thingiverse.com/thing:801279).