The ACME (Another Cupholder Misguidedly Engineered)

Here is the ACME (Another Cupholder Misguidedly Engineered). If you're like me and you drink from big bottles, but can't or despise using the doorcard pocket, you'll want this. It is designed to fit any bigger bottle and any cupholder size through the usage of compliant mechanisms. It also has a recess for a handle in order to (hopefully) fit those big water bottles and mugs the Americans love. Don't have any around to test though.

There are two files: One for the body itself, one for the three prongs that (hopefully, depending on your printer) press fit into the top slots. Their orientation is correct for the porpose and they can be glued in place if needed. The body has three more prongs on the bottom that act as a compliant mechanism in order to press into the walls of the existing standard-sized cupholder, therefore keeping the adapter in place. What I found as a limitation to the design are far recessed original cupholders, such as in the Yaris, where the front cupholder cannot be used due to existing geometry. The back cupholder fits the ACME very well though.

The whole adapter was designed for high-warp, semi-elastic filaments, specifically ASA (white in pictures), from which it was tested in real life on a couple of cars (Toyota Yaris, Toyota Corolla). It should work well when printed in ABS or PA, but I don't have the ability to test them (for now). It works in PETG (grey one in pictures) as well, but only if outside temperatures don't go over 30 Celsius, since above that the temperature inside the car might permanently deform the prongs and they will lose flexibility. HT-PLA as well as ANY FIBER-REINFORCED filaments are out of the question since they are not flexible enough for the compliant mechanisms to work twice, that is to say "don't blame me if you've printed in PETG-CF and the prongs snapped". 

As for print settings, go for whatever temperature, cooling and speed work for your filament, but otherwise use:

• >25% crosshatch/gyroid sparse infill (the difference between 10% and 25% is 5g, so well worth it)

• 3 walls

• no scarf seam (it might mess with the structure)

• precise wall

• precise z-height

• avoid crossing walls (especially if printing in PETG or PA)

There are no supports needed, even if your slicer might suggest them (the white ACME in the pictures was printed in ASA with no fan, so I know it works). It should not warp off the print bed either since there is some special design on the bottom that prevents it. If it does though, put some mouse ears and it should be ok.

Keep in mind that the white one (ASA) in the pictures was printed on a semi-enclosed Sovol SV06 with a 0.6 nozzle that reaches a chamber temperature of 38C on a good day. Your non-janky printer should perform much better than mine did.

STEP files included as well