About this 3D model

I have a large water bottle that doesn't fit the regular cupholder in my Chervrolet Trax, so I downloaded a one piece adapter that was too big for my printer. Based on that concept I designed a collapsible adapter that could be printed in place in my MonoPrice Select Mini. I printed 2 of them, in black generic PETG and they worked well, but one of them shrunk to a point that my water bottle friction fit it after leaving it in a closed car in direct sunlight. I printed it with 5 walls for sturdiness, maybe overkill but the water bottles tend to be very heavy while full.