Huge, quiet fan case side replacement for Qube 500!

I love Mini ITX cases, I have been using the Cooler Master NR200 for a while now. It is a good case but does not stay as cool and quiet as a larger case can, smaller fans just make more noise for the same airflow and there is no way around that. The bigger the fan the better, all else being equal. And Noctua make an amazing 200mm fan, NF-A20 PWM which I happened to have lying around… 

So when I saw the Qube 500 it was obvious, replace the unfeatured side of the case (named TG-PANEL in the model) with a fan side. But I don't have a 3D printer that can print something so large, almost nobody does. Instead I made it in quarters with the fan an integral part of the structure - this is an easy print with a mid-sized printer like my MK3S.

Fitting the side of the case looked complicated at first but notice the BOTTOM-PLATE model has two nice rectangular holes in it, symmetrically placed on top and bottom! I was able to design clips that should clip straight into those holes holding the case side securely. When I get my hands on a case I will be able to test and revise the clips but I think they will work. To avoid a complicated print using supports the clips fasten to the case side quarters using M3 bolts and brass threaded inserts.

The four quarters are printed with no supports, flat on the bed. The four case clips are printed with no supports, on their sides - this is important, you want the filament to allow for some flex without breaking, so no flexing across the layers and PETG is recommended. If you really wanted you could allow supports in the holes for the brass inserts - but a less than perfect top inside surface won't matter, you will be using heat-insert brass inserts in those holes so you will never see the inside again.

Once the eight pieces are ready check them over, test fit them together, and then insert the threaded inserts - two into each of the towers on a quarter piece, and two into each case clip. When that is done there is only one way the quarters can go together - fasten them with the 10mm bolts. Don't use too much tension, you can compress or crack plastic if you overtighten. The clips attach to the insides of the quarter pieces, one clip per piece, with two 10mm bolts each.

When assembled note that the piece called  “lower right quarter” has a slightly different outline for the fan. The Noctua fan is not perfectly symmetrical where the cable comes out. It will fit if the cable is tucked under the fan (label facing outwards) as the fan is inserted. Then attach the fan to the assembly using regular fan screws from the inside of the four-piece panel, or using 40mm M3 bolts if you prefer.

M3 hardware is used throughout, 16 hex socket head 10mm bolts and 16 M3 brass inserts. The inserts I use are stepped and go in and stay in well with a 4.5mm hole, 6mm deep. The ribs of the four quarters surround the fan and provide strength against flexing, and a sturdy surface for mating the four parts together.  It looks a bit industrial but I think the exposed hex bolts enhance the look of a very utilitarian case design.

The Noctua NF-A20 PWM model was made by Michael Witt, and is available on Grabcad.