Small water pump for N20-like motor

thingiverse

A compact water pump designed for toy electric motors features a 0.9-1mm shaft, a 12mm casing diameter, and two flat areas on opposite sides. This device resembles a "N20" motor, similar to the one found at https://www.ebay.com/itm/Mini-MNB-N20-DC-6V-12V-33500RPM-High-Speed-Micro-12MM-Motor-DIY-Toy-Hobby-Model-/322643405199, but since it's extracted from junk, its exact type remains unknown. The motor can be longer without issue. After creating the rotor and casing, ensure the rotor turns smoothly inside the casing. If not, reduce its size or grind it down until it's 0.6mm or less away from the casing. Remove the motor and apply a thick layer of lubricant to its shaft to prevent water entry. Reinsert the motor and rotor. It's also highly recommended to secure the rotor to the shaft with a small amount of high-viscosity superglue. Water resistance can cause the non-glued rotor to detach even if it operates fine in air or short bursts. If the motor spins properly, attach it firmly in place using glue. Then, apply glue to the top, ensuring it doesn't enter the pump but covers the joint completely for a watertight seal. This water pump comes equipped with 4mm hose barb tips compatible with standard 4mm i.d./6mm o.d. aquarium hoses. However, insert them carefully as they prioritize unobstructed water flow over strength. This device is suitable for small desktop water fountains or car swamp cooler water recirculation pumps, such as the one found at https://www.banggood.com/12V24V-35W-Dual-Input-Mini-Air-Cooler-Fan-Water-Ice-Evaporative-Portable-Air-Conditioner-p-1261035.html?admitad_uid=915fcb44b9c0adef45a8f89cfe695c4b&utm_content=615449&tagtag_uid=915fcb44b9c0adef45a8f89cfe695c4b&ID=49554&cur_warehouse=CN. Generally, it's best to print the casing first, followed by the rotor and lid last, allowing for adjustments based on tolerances with minimal plastic loss.