Improved holster for Tandem T:slim X2 pump with integrated clip

This is a case for the tandem t:slim x2 insulin pump. It prints in one piece, requiring no additional hardware, is fairly easy to post-process it to a point where it is comfortable to wear in contact with skin, and includes a clip which grips much better than the one that comes with the OEM pump case.

I highly recommend PETG for toughness, UV resistance, resistance to creep, low wear over time, and tolerance to a fairly wide temperature range.  You would probably also have good results with the hardest TPU you can get ahold of, but I have not tested this.  I recommend against PLA (even e.g. PLA+ or Tough PLA), as it still lacks some of the listed benefits of PETG; remember, this is meant to be worn out and about, and you don't want it to get brittle from the outdoors, or soften and deform in a warm car.

I also recommend starting with the included .3mf file; I used a trick for stronger parts (described below), so if you want your new pump case to be as sturdy as possible, and don't want to have to think so hard about tuning every slicer setting to achieve this, the .3mf file is a good starting point; you will likely still need to adjust it so the slicer uses your printer and filament settings, but the print and support settings should be about where you want them. YMMV if you choose to slice this from scratch.

I also slightly adjusted the dimensions of the case (99.5% scale in X, 101.25% scale in Y), after a few iterations showed that it did not quite fit as well as intended.  Maybe my printer is slightly out of alignment, and you'll have to tweak the sizes for your own printer, but this was not so painful to do a few times; now I have the file saved, and I can reprint it any time I need.

The slicer trick I uses is as follows: Orcaslicer has a setting for adding an extra perimeter every other layer. Combining this with some careful line widths and an extrusion multiplier, and we can emulate brick layers, which enables much stronger parts. For the uninitiated, this means that, rather than putting a line of molten plastic directly on top of one line on the previous layer, we print halfway between the lines on the previous layer.  This means we are printing over more of a gap (since the lines are somewhat rounded, printing the typical way leaves tiny air gaps at the corners between every line and between every layer), and if we increase the extrusion rate to better fill that gap, we now have a better shot at filling every nook and cranny inside the part.