I know the LACK enclosure is very popular, also because there is a great step wise manual how to build one, from PRUSA itself. For me personally I did not like the idea of putting my printer into a better cardboard box though, even if I was already sold on the general concept of an enclosure.
So I was looking for alternatives and I was surprised I did not find any enclosures based on the BROR shelf system. It is not as dirt cheap as LACK but not unaffordable either and the dimensions are similar, even if 10 cm broader and of course higher. As I could not find anything I simply designed my own and here it is.
The design is actually for MK3s+MM2s but it can just as well accommodate a pure MK3s system. The only change would be the number and location of the filament holes.
You can find the print files, purchase list and assembly instructions on prusaprinters in case you'd like to have an enclosure based on a sturdy powder coated steel shelf.
I'm new to printing and so far have been using it on the corner of a desk for PLA. Am going to be printing some ASA soon so have modified an old shelving unit into an enclosure. It'll do for now but having been reading about the fire hazard aspect your post is very handy thanks.
I've been thinking of using polycarbonate rather than acrylic as its more resilient to heat and class 1 self extinguishing in the event of a fire. I haven't found any recommendations for this but not sure why not. I may be being a bit paranoid but I thought if something did go wrong then they're be more hope of tackling it with a fire extinguisher. This wouldn't of course be of any benefit when leaving the doors open for PLA.
Anyway, thanks for posting I will have a look at the BROR metal ranges in Ikea.
Are you using the Bror shelves as well? How is the enclosure coping with the weight? I have a 40 x 40 x 5 concrete slab like your photo and it's heavy AF. I think Homedepot says it's ~15kg + 7kg for Mk3S.
My stone plate in the Bror enclosure has also 15 kg, pretty much the same as a concrete slab of that size.
In general the BROR shelf has absolutely no problem with that weight, it is designed for much larger loads (the manual claims 100 kg), as long as they are spread out sufficiently across the shelf (which a stone plate obviously is on its broad side).
The only issue is with getting the support of the shelf floor right. By IKEA design there is only a central support beam below the shelf floor. That is rather terrible for our purpose as the printer and/or the concrete/stone plate with a printer are going to wobble left and right a that way. The shelf floor acts like a spring in that case. That is why I modified the design, by adding two more of the same support beams, 12 cm left and right of the central one. Those beams can be simply clamped into the frame, once you bend the small latches of the support beams inwards. With that modification the whole shelf is rock solid even when the printer is moving rapidly.
If you have 3 shelf floors (in my design I actually have 4 of them) you will have the needed support beams as you have no use for them for the top plate anyway and also not for the shelf floor I used as back plate.
You can see how the underside of my Shelf looks like. The grey aluminium profiles are not of much use but as I have them already I kept them in place. The 3 black IKEA support beams (only the central one is supposed to be there according to the IKEA manual) are what make the design very stable.