I/O plate for APM Mustang

Applied Micro Mustang uses standard Mini-ITX form factor just like many PC mainboards. The problem is that contrary to PC ones it does not come with I/O plate. So I decided to make one using 3d printer.

First version

Loaded Tinkercad page, did quick measurements and sent STL to my brother-in-law Szymon for printing. That’s how v1 was born.

It was not good:


As you may see several ports were misaligned (or too small). So I moved ports a bit. The other problem was thickness — turned out that 1mm of plastic was too weak. Second version got printed as 2mm thick:


Other filament made it look ugly. And shows that my measurements were wrong.


My brother-in-law uses FreeCAD for his designs so I decided to recreate model of I/O plate in this tool. There was some cursing involved as their approach to doing holes in objects. On the other side positioning of holes was much easier to do.

There were several changes and versions were moving fast. I decided to not put any 3d text on model for several reasons:

Fifth version was 1mm shorter as I had to add space for screws in case:


At this moment I left APM Mustang for my brother-in-law to make changes easier.

In meantime we got some hints from people more involved in 3d printing and decided to do some other changes to how model is done.

Mesh design

FreeCAD has this idea of ‘mesh design’ - you select object, create mesh of it and then export it as STL. The problem is that this part is completely broken under Ubuntu (used by Szymon) — it creates mesh elements but with 0 points/faces.

Seventh version

6th version existed for a moment and then 7th came as first one using mesh:


Not that it changed much ;D

Final one

Few more iterations, another set of measurements and finally we got version which went into use:


It is still far from being perfect but does it’s job. As 3d printing n00b I have no idea why there are vents around holes for ports. Maybe something wrong in printer setup or slicer configuration. Suggestions are welcome.

One button is for power, other for reset as case had just one button on front panel (which I do not use).

Files to download (MIT licensed):

3d printing computers mustang