Reverse CAD Atari ST case.

[Marcopolomint1]

Hi all, new to this forum but couldn't find a similar thread.

What would be the appetite for a full fidelity +/- 0.2mm accuracy ST case (both lid, base) and possibly also the keyboard panel?

I'm a Mechanical engineer have worked in product design amongst other applications for decades so used to building accurate CAD models.

It has countless uses for upgrades, mods, giving feedback on space under shields etc...

As far as i'm aware the original mould tool was never located. I suppose Atari could be approached to see if there were any drawings
in it's archives but they are unlikely to respond.

Also wondering if there were any physical differences in the STFM vs STE case. I don't think so....

cheers,

Marco

[exxos]

Have a look here viewtopic.php?t=224

[Marcopolomint1]

Apologies, I will post in that thread if you need to delete this thread. My bad I used wrong search terms.. I have a few insights etc I can maybe add to the discussion there.

[rubber_jonnie]

Also wondering if there were any physical differences in the STFM vs STE case. I don't think so....

cheers,

Marco

The STFM and STE cases are broadly similar, however the STE case does have some physical differences and whilst an STE mainboard will fit in an STFM case, it needs a little work to fit properly.

First off the STE has stereo audio output not present on the STFM, so they need case holes.

Next there are 2 joystick ports on the left hand side. These require the molding to be different to expose them. You can use an STFM case but if you do then they can't be seen/accessed without cutting the case.

They support Jaguar pads AFAIK, but I'm not sure if anyone uses them.

There are some variances I've encountered with cartridge ports as well but that is a more general thing rather than an STFM/STE thing, and it relates to the way the main PCB is supported at the cartridge port.

Unfortunately it's not a one size fits all scenario, and whilst the case top is shared, the bottom half does have the differences I've mentioned.

[Steve]

Hello Marco,

The Atari STf case has already been turned into very high quality CAD models, in both full-size and 3D print 2-half sizes. I have them on my hard drive but I can't remember who made them, so I feel awkward uploading them without crediting the author, but I can upload them here.

Screenshot_20260715_153404.png

[JezC]

Not wanting to muddy the water too much here...but even the top case has some differences because of the different eject buttons for teh floppy drive.

Early drives had a 'long' eject button while later machines had a much smaller eject button.

So the only consistency is the inconsistency :(

Edit - the post by Stece above shows the long eject button case

[Steve]

I am guessing that editing this STf CAD model to conform to STe and even Falcon isn't too much of a task, especially for a professional.

[Marcopolomint1]

I was going to post my insights on the 39 page thread Exxos linked to but maybe just better post them here now I've read that whole 39 page thread.
Say for arguments sake what we're talking about creating is a saleable item; professional looking consumer polished. All hypothetical.

1. FDM/SLS/SLA prints are not going to work because of surface finish and colour/colour depth and consistency. In moulding world we talk about VDIxx finishes on parts so for example the ST case looks to be about VDI30 which is quite a coarse texture. I've moulded in VDI24 a lot for tactile consumer stuff and it's defo smoother than the ST case. There are VDI charts I can check against. There are many other logistical reasons not to FDM, least of all pillar strength, wall fragility etc....

2. CNC, Laser cut, been down these routes they have their uses. Not for this but I picked up this was a non starter in the big thread. Did a hideously complex 5 axis CNC job for a client on a block of plastic and the cost was horrific.

3. Steel tool mould which we generally call hard tooling. mega bucks. My far east moulders would quote about 15-25K per side top/bottom in ABS. That's 30-50K for a whole ST set of parts. Suitable for 100,000+ shots per tool. Also the moulder often have multi shot tooling where for example both the lid and base are in the same mould or there's 4 lids for example in one shot but those tools are ever larger and more expensive.

4. Vac cast, vac forming (yes they are two different things). Clunky, low fidelity, weak , poor surface texture control. Non starter. Foam blown and roto moulding are also both unsuitable.

5. casting, re-moulding...again you just won't get consistent results and cost is prohibitive.

So I think that summarises those 39pages.......here's my solution and I'm offering no guarantees as it needs verification but it's what i'd do:

6. I do tooling for low volume runs also, and when I mean low volume I mean up to 1000 for example, I use what's called in the industry "Soft Tooling". Now this isn't to be confused with silicone moulding/tooling. These tools are cut from much cheaper, softer metal, usually aluminium or mild steel. These soft tools (depend on draft angle and shut out angle for example on the vent fins) generally only last hundreds or few thousand shots. Bu they do last. For soft tooling of the size of an Atari ST you're probably looking at about £5-8K per top and bottom, so around £10-15k total. The higher costs are also associated with the fact that the larger tools have to be used on larger machines, this one needing about a 200tonne machine. Cost per mould maybe looking at around £30-£50 per set but big caveat on this as price changes are mental just now. As a side note the quantity of faces you have side-cores on (i.e. side ports effects the cost too as they aren't on the tooling line of draw and require extra pneumatics.). Moulders use what's called "tool inserts" when they want to create variations within the same tool, as long as the main fundamental underlying geometry is the same. I can get quotes for soft tooling with the CAD. or not, LOL!!

cheers,

Marco.

[Marcopolomint1]

I am guessing that editing this STf CAD model to conform to STe and even Falcon isn't too much of a task, especially for a professional.

No, fairly straight forward.

[exxos]

My last thoughts was split the case into flat layers and it would make even 3d printing possible. But it's time in developing how it would all reliably fit together.

Problem with full cases, very large and expensive to ship. Probably £100+ these days overseas and chances it arrives not broken..

Things like the vents could be printed in 3 chunks. If a chunk gets broken, it's cheap and easy to replace. We also was working on the idea for removable back panel to fit various motherboards. But time is never enough for all the projects.