Installing panels at home using countersunk screws, I'm normally using premade plastic 'button-heads' to cover the screw heads once installed. However, my local Bauhaus failed to have the correct size on shelf, meaning I had to think for myself...
So, without further ado, I bring you custom designed button-thingies to click into the torx of eg screws used for securing panelling. In my case the screws were 5*70 T20 - but as I am also providing the sourcecode for OpenSCAD, you are free to adapt them to your personal use. All you need is a vernier caliper, OpenSCAD and time to fiddle.
I've become addicted to OpenSCAD, as it is simple, provides total control and relies on a process I'm familiar with; textual programming. Here, the output is a 3D-object :)
Designing this thingy required me to either invent something on my own (hard) or copy (easy) the crucial part - the torx. Therefore I've copied a module generating a torx from here.
The rest - the buttonhead itself - is not much to talk about.
Looking over the code (excluding the insanely complex module written by my norwegian muse), you'll find it easy to adapt it to suit your needs - and your printer. With this being something that requires a snug fit to stay in place, you'll have to be prepared for a little experimentation.