Centrifugal Water Pump - hand drill driven

thingiverse

It is a water pump that can be easily driven by a hand drill. I got inspired by firefighter pumps. With a rotational frequency of about 1200-1300 rounds per minute I measured a maximal flow rate of about 60 litres per minute at zero pressure. At zero flow rate I got more or less 2,2 metres of pumping height or 0,2 bar. When used without anything connected, the water splashes about four metres away. It is not self priming, although it starts to pump the water already when it is barely touching it with the blades. For making it you will need a Ø 8 mm shaft (a threaded shaft might work as well) and two 608 bearings (better 608-2RS). It would be best, if there is a press fit between the shaft and the bearings. Furthermore you need some M5 screws & nuts. An Ø 8 mm O-Ring with 1,5 mm section is advisable as well. I created two impeller designs, but I couldn't find big differences in performance. Please let me know if you do. You can glue the impeller to the shaft, but it should be enough to simply press it on. Anyways there needs to be a 1 mm deep cut flat area on the shaft to transmit rotation, as shown on one image. The sealing can be printed with TPU or you use silicone instead. You can run the pump as well without it. That garden hose adapter is optional. It needs an O-Ring (Ø 11 mm x 2,5 mm). With long pipes it is not working very well as the pump isn't providing much pressure. I recommend using the pump without garden hose and adapter. As it is, I think it is not working perfectly yet. I might as well make another version at some point. So far I haven't tested it out with much higher speeds. If anyone is trying it, I would be happy to hear about it (comments or make-section). I am also open for ideas to improve. PRINTING: You can print it with PLA at 0,10 - 0,30 mm resolution with 20 % infill. I recommend to print thicker walls. The two pump housing parts need support. All takes about 12 hours and 180 grams of plastic.