This is a simple peristaltic pump I designed. It uses a 755 motor and 608 bearings that fits 3.2mm Bore Size Silicone tubing.

The motor is mounted into the rear of the frame using M4 screws,
The bearings and bearing mounts are friction fit, but are snug enough that I have not had any issues even with a few hours use.
There is space underneath for a 2x18650 battery box.

It does the job of getting water from point A to B.

Very tight fit, in the images I have printed in PLA at 0.2mm layer height.