This is my fourth generation of electric turbopump that can supply extremely high pressures of fuel to a small rocket engine. Similar to the pumps in Rocketlab's Electron rocket, it uses a very powerful brushless motor to create extremely high pressures. It can be used for either water or fuel (depending on what material it is printed out of) and can be used for much more than just propulsive applications.

Performance: (with a 2050kv waterproof brushless motor)
This pump can easily produce up to 240 PSI in water if fully submerged, with pressures higher than that causing cavitation. I hope to improve the cavitation threshold in future designs, but this working pressure range satisfies my current pressure requirements. The working fluid is sucked in around the motor to dissipate heat quickly, as this pump will draw 930 watts at full pressure on a 4 cell lipo battery. Because the battery voltage goes down to 15.2 volts at full load, I can calculate that the impeller spins around 31,000 RPM.

Printing:
This Pump will push the structural limits of most common materials so make sure to print in a material with really good layer adhesion to avoid delamination at these extreme pressures. Because everything is fluid-cooled, PLA is actually a good material to use for this. PLA works really well for this if printed really slowly and slightly above its recommended temperature, ≈ 230C. This will get excellent layer adhesion but it increases the risk of clogs and will need to be printed in a well ventilated area.

Pump Housing - 100% infill 10-20mm/s PLA @ 230C no support

Pump Housing Top - 100% infill 10-20mm/s PLA @ 230C support required

Pump Impeller - 100% infill 10-20mm/s PLA @ 230C no support

Assembly:

• Clean all printed parts thoroughly to ensure smooth inner surfaces and a close fit
  between the impeller ant top housing.
• Attach the waterproof motor to the top housing with 3x m3 x 12mm countersunk screws
• Press the impeller onto the motor shaft with the print seam lining up with the flat side of
  the shaft until the perimeter is nearly touching the top housing. If necessary, use a small
  dab of epoxy or CA glue to secure the impeller to the motor shaft.
• Apply a thin bead of hot glue to the inside edge of the lower housing and while still hot,
  press the top housing into place. Make sure to align the perimeter screw holes.
• Use 10x #8 x 3/4in thread forming screws to tighten down the housing and fully seal the
  two halves along the still malleable hot glue bead.
• Use a 1/8-27 NPT tap to thread the output for whatever adapter fits your project best.
• Make sure to check for leaks and make sure your impeller is secure through the full
  operating range before use.

Safety Note - This pump will generate very high pressures that have the potential to cause serious injury. Do no stand near the pump while it is in operation without appropriate PPE to protect you from flying debris or fluid injection injuries.