electric water gun

thingiverse

Summer season started here in germany. It's hot and and I wanted to cool down. Using water. My cheap watergun broke and I wanted to build my own. An electric one with a big tank, a good range and cheap parts. This is the result. It has a 1,2 L water tank and a range around 8 meters, depending on the nozzle and battery level. It is also possible to "quick charge" the water tank, by pressing the tank under water. For this feature the pump should be sealed with enough silicone :) You will need: - 12V universal windshield washer kit (https://www.amazon.de/gp/product/B077N3V7H1) -> The one in the link is the exact same one I used. - 3x 18650 Li-Ion Battery -> I used old ones, I ripped off an old laptop. Be careful! - 1x HX-3S-01 3s Li-Ion BMS (https://www.amazon.de/dp/B07T3B3F8X) - 1x Small step up(Boost) converter (e.g. https://www.ebay.de/itm/253381738734) -> Set this voltage to 12,8V - 1x USB C Breakout (e.g. https://www.ebay.de/itm/284897735457) - 4x M3x12mm Screws - 2x M6x12mm Screws - 2x M6 Nuts - 2x small wood screws for the nozzle (3x10mm or something like that. I don't remember :)) - 1x E3DV6 Nozzle (0.8mm worked the best) - Wires - Superglue - Zip ties Solder the Li-ion in series and connect the BMS according to its schematic, connect the output of the boost converter to the BMS and connect the VCC and GND pins from the USB C breakout to the boost converters input. Connect the output from the BMS with the water pump and connect the button in series between the pump and the BMS. I covered all the electronics with clear varnish and a second coating with silicone. I screwed the nozzle adapter directly into the tank. The lid is a bit loose, so I glued it permanently on the handle with superglue. I also mounted the PCBs with superglue. The cables and the hose is mounted with zip ties.