Constructing the Side Panels and Middle Tray
According to the instructions included with the Praxis WetBench, the test bench's construction takes a mere seven steps and can be completed in 10 minutes or less. I would recommend taking your time on the construction, to make sure you get all the parts together correctly and don't crack any of the acrylic panels.
Steps 1 and 2 in the instruction manual covers putting together the kit's side panels and middle tray.
The two side panels consist of the a steel side panel mated to an acrylic panel behind it. The two panels are constructed using a single M3 5mm hex screw, a split washer, and an M3 thumb nut per side affixed through both layers through a hole in the middle bottom of the panels. The acrylic piece sits underneath the steel panel, both shadowing and contrasting the base color of the front steel panel.
The acrylic side panel is laser cut to fit the space on the inside of the steel side panel, resting in between its edges. Both parts are cut to fit together perfectly all venting and mounting holes matching up exactly for no fit issues. Each of the assembled side panels has t-shaped mounting holes along the lower back and two sets of eight vertical and angled mounting holes along the upper right for mounting reservoirs and/or pumps to the test bench.
Along the inside upper folded edges of the steel side panel are threaded mount points for mounting the motherboard tray and the back panel (radiator / fan tray). Along the bottom folded edges of the steel side panels are rubber feet to cushion the test bench against vibrations and to hold the bench in place.
Step 2 of the assembly instructions adds the middle tray to the side panels, giving the test bench is shape and center support. The test bench is not yet usable in this configuration, requiring the addition of the motherboard tray and back panel to give the test bench is full rigidity.
the middle tray affixes to the assembled side panels using four M4 6mm hex head screws through holes along the mid-point of the side panel. The screws thread directly into threaded holes in the left and right sides of the middle tray and side panels. The middle lip on the left and right sides of the tray side along the outside of the side panel with the outer threaded tabs sitting along the inside of the side panel. The two middle screws go through the tray edge and screw directly into the threaded hole in the side panel with the outer screws going through the side panel and into the threaded tabs on the tray. This sandwiches the side panel between the two tray mount point for added strength and stability between the tray and the side panel.
The middle tray itself has mounting holes for the PSU cage, the 5.25" device bay, HDDs, and SSDs along its to, as well as top, middle, and lower cable pass-through holes. All drive mount rails and cable pass-throughs are clean cuts with no rough edges, preventing the possibility of catching or nicking cables (or fingers for that matter). The inner rails are for mounting SSDs, the middle rails for HDDs, and the outer rails for the PSU or 5.25" device bay cages. The cages are bottom mounted while the HDDs and SSDs are mounted directly the tray surface. Underneath the tray, the edges are folded down to give the tray added rigidity and strength. The four side mount points are located along the left and right edges of the tray, with the outside holes threaded for flush mounting to the side panels.