Pet Project: Printable AT computer chasis (Needs huge printer)

[wierd_w]

I have started work on creating a 3D printable AT/ATX computer chasis, since Thingiverse came up mostly dry. (there *IS* a computer chasis on there, but it is far too modern, has zero provision for retro boards, and is meant to be printed in a buttload of sections on teeny tiny printers) The intention is for AT retro board builds, more than anything, so I am enabling provisions for retro style port cutouts and pals.

 

The current iteration of my in-work draft is able to fit on my AnyCubic Chiron, at least as far as Cura is concerned.  The chiron is huge, but slow-- it is about the most affordable of the huge format 3D printers, as far as I have seen.  This thing WILL NOT fit on a smaller printer.

 

The chasis itself is very much a "boring beige box", but this is intentional.  I intend to release the base model (including .STP format for import into whatever CAD you might have) as CC:BY, so if you want to make something neat out of it, knock yourself out.  I do not care what that neat thing is, or even if you choose to sell it. Just mention where you got your data from.

 

As-is, I am designing the entire thing as a "Print in one go, Print-In-Place" arrangement, where there are small gaps that are easily bridged by the printer, but are sufficiently wide that adhesion will not occur, so that the case lid, all the front cover knockouts, port knockouts, and slot knockouts print "fully supported".  Support material will be designed and modeled in place for trickier bits, like the drive retainer cage, the top of the chasis, et al. Ideally, you would totally turn supports off in your slicer.

 

The knockout for the ATX form-card rectangle will have an appropriately positioned round hole where an AT style DIN5 keyboard port would be found when fitting an AT board.

 

 

Here's some pretty captures from my CAD software with my work-in-progress-- (Do note that I have not designed retainer cages yet for the drives, nor added provisions in the front for power button, Power/HDD LED, Reset Button, Turbo Button, retention of PC Speaker, or anything like that yet. This is still WIP, I am just sharing what I am working on: )

 

 

 

 

When I release finished data, if you intend to print one, please use a suitably temperature stable material, like PETG or ABS.  While I understand and empathize that PLA is both easy to print and cheap, it deforms at 70C, and the inside of the case could reasonably get that hot if you have retro components in there.  If you use PETG, please apply a uniform coating of PVA glue on the bed, as PETG is infamous for destroying glass beds, and the Chiron totally has one.

 

 

Again, Cura thinks it will totally fit, but just barely:

 

 

 

 

 

Comments, suggestions, abject ridicule-- all wellcome!

Edited October 19, 2021 by wierd_w

[carlsson]

Honestly I thought if you were to build your own chassis, you would construct it from metal, wood, plastic sheets etc that you cut and glue together, not something I would expect you to 3D print even if you have a big capacity printer.

 

But good luck with your project. Correct me if I'm wrong, but shouldn't the ATX panel on the back be near the edge of the box, so you can mount the motherboard against it? From what your design looks like, you would have a spacer across the middle of the chassis where the motherboard is attached, or maybe I'm confused.

[wierd_w]

There are IO cutouts for discrete cables (as found on AT motherboards from the early 90s, or from IDC pigtails as found on mutli-IO cards, from the late 80s.), above a rectangular cutout (that has the print-in-place knockout in place in the images).

 

The rectangular cutout is in the correct location for an ATX form card. 

 

The knockout will have a suitable hole for a DIN5 keyboard, for use with an AT style retro system board. (286, 386, 486, etc...)

 

 

The IO cutouts will have print-in-place knockouts inside them also when I am done (meaning knocking them out is optional.)

 

Edited October 19, 2021 by wierd_w

[carlsson]

Aha. I think the majority of AT cards I've seen had a handful connectors directly on the board, but those may have been specific brands which always was a problem if you wanted to use the board in a different case.

[CatPix]

Older AT board might have several connectors, but from what I've seen, by the early 90's up to the end of AT, the only standard connector was the DIN one, everything else was provided as "discrete cables".

Early ATX case were compatible with AT and there were those "plates" with only the DIN hole on it

[wierd_w]

Correct! Most 386 and newer AT style clone boards just have a DIN5 as an integrated port. Everything else was either done as an IO board, or was an IDC header on the board, they intended for you to put a discrete pigtail on.  Sometimes they didnt even put the posts on the header. (especially for ps/2 ports)

 

The IO knockouts provided are:

 

2x DB25 (parallel port, or 25 pin serial)

 

1x DB15 (Standard PC gameport, or an older scsi connector. Usually gameport. Frequently found on 90s vintage multi io boards as an IDC header)

 

2x PS/2 port (or ps/2 and RCA female, such as routed from an EGA wonder, which exposes a composite-out signal as a 4 pin IDC header. Said header was intended for use inside a compaq portable / portable II, to attach to the internal monitor. It can be routed out the back just as easily, for ega on a composite monitor.)

 

2x DB9 (or vga pigtail, for whatever reason)

 

All of those were frequently supplied with io cards or motherboards of that vintage. I am just providing a convenient place to mount them.

 

The emphasis of the project is for AT boards, but if you desperately need a chasis, and shipping is too delayed (or you want a very custom bespoke chasis, and have the skills to doctor this bland beige box into one) this project is accomodating.