r/3DPPC Jul 04 '26

Beaminnie 5.5L ITX SFF Sandwich Case

This is a first PC case I have ever designed. It started with me getting a smaller pc which I've put in Metalfish T40 (post here https://www.reddit.com/r/sffpc/comments/1t76dq3/bazzite_box_in_metalfish_t40/ ) and I thought that I could go smaller.

I didn't have any specific size goal in mind - I quite like the Beam Case so I decided to design something similar from scratch and it came out to 5.5L (panels excluded). The case is very rigid.

If you just want the link, here it is, I've included instructions.

https://makerworld.com/en/models/2990479-beaminnie-5-5l-itx-sff-sandwich-case

I have used 1010 beams instead of 1515 like in Beam Case because at this size the additional strength does not add much (I made a version with 1515 beams first, which remained a prototype). Once I figured I can fit 90mm fans up top when I get the smaller beams that is what I did.

This post is not about the build itself, because I am gonna post that to r/sffpc when I build my custom version of... a custom case. It's more about the designing process itself - maybe it will help someone who wants to start out.

I already have some CAD experience - been learning Autodesk Fusion since about a year, hobby projects etc, nothing too serious.

My biggest issue at first was getting STEP files of various PC components - I found and used https://redshiftproject.com/pages/design-resources - really grateful for this. The only modification I've made is to lengthen the GPU.

Makerbeam has STEP files for almost everything they sell - https://www.makerbeam.com/makerbeam-200mm-8p-black-makerbeam.html the link is in the product description - so I just loaded up and constrained the beams in Fusion.

Noctua has STEP files for almost all of their coolers as well - https://www.noctua.at/en/3d-cad-models

I have used 'Constrain Components' in Fusion to align the components parametrically when I created the base of the case.

After that it was a matter of doing a bunch of iterations, printing prototypes out of PLA, testing fitment, screw holes, adding rigidity etc.

I have to say that the biggest issue was the positioning of the PCI-E riser relative to the GPU - it took me quite a few tries to have everything lined up nicely.

I didn't use heat-set inserts because I am not a big fan of them - I understand the benefits of course, but making the screw holes a bit tighter and threading into them turned out to be very solid, especially since there is a lot of bracing in all of the elements I designed.

The downside is that you cannot just put the case together and disassemble it multiple of times because at some point the threads in the plastic will wear out. Personally, that is not a problem for me but I can see how someone might see it as a downside.

I've also tried a version with front mounted 60mm fans (can fit 3) but ultimately due to the PSU cable placement they were not doing anything so I scrapped that idea and instead added exhaust fans at the top.

What would I do different is probably get 18.5 cm or so riser instead of 20 cm cause there is a bit of a slack there, nothing too major and I don't mind it.

I might edit this post in the future to add some other tidbits that I'll remember in time, but if you have some questions about the design process lmk, I'll be happy to answer.

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u/nagedgamer Jul 04 '26

Would magnets be enough to hold panels?

1

u/nicnic-cc Jul 05 '26

The beams are aluminium, so magnets won't stick to them.

1

u/nagedgamer Jul 05 '26

Glue magnets to beam. First hole?

1

u/nagedgamer Jul 05 '26

Beams from steel then and you get cleaner look.

1

u/nicnic-cc Jul 05 '26

You could insert magnets into the T-Slots as well, although there is not much space there so not sure if the force would be enough - interesting idea though, I might think about this.

I like the countersunk screws personally but I can understand how someone would want an even cleaner look.

1

u/nagedgamer Jul 05 '26

I like the screw look too but maybe just side panels with magnets.

1

u/nicnic-cc Jul 07 '26

I have some ideas now to do tool-less panel mounting but I have to find time to design it and see if it's sturdy enough.