Remixed this part from mikolaszuza PSU Frame brace.
The release of the video and the brace came at the perfect time for me, while I was thinking about some details on my own LACK enclosure setup.
There are two versions:
V1: 1:1 design only with replaced mounting points
V2: replaced mounting points + cut-out in the midsection, for better looking and more vertical shells to get a little bit stiffer also its safes some filament.
I am not totally satisfied with the mount because on the mk2 the lower PSU mounting point is much smaller then the aluminium extrusion bar on the mk3 frame. But without spool holder on top of the printer it should be fine. When you push against the frame the lower horizontal part of the braket bents a little bit.
PS: nice video i found about "infill & shells setup an strength comparison" https://www.youtube.com/watch?v=AmEaNAwFSfI
printed with slic3r prusa edition
Fill pattern: Honeycomp
Vertical shells: 5 Perimeters
Solid Layers: Top: 5 Bottom: 5
Used Filament: 65g (estimated)
printing time: 4 h:55m (real printing time)