Pascal Engine

thingiverse

This DIY boat engine incorporates the fundamental principle of the pop-pop boat mechanically. Water is drawn into and expelled from a pressure chamber by means of a diaphragm moving up and down regularly, utilizing a periodic motion. I attach the engine to a styrofoam "hull" and corrugated plastic "deck". The boat can move at a speed of about 15 cm/s. Note that this engine features no underwater moving parts; the diaphragm is situated above water level and only pushes and pulls trapped air inside the chamber. The diaphragm in this case is made from silicone rubber molded onto a 3D printed form, but other materials could also work, such as plastic bags or umbrella fabric, possibly reinforced with silicone sealant for sealing. The power source is a 130 DC motor running on 2 AA batteries. I designed the chamber with support material included in the STL file (vertical clearance 0.5mm) because automatic support blocks the outlet hole. There is also a version without support. The second gear was printed twice and features plain 3mm shaft holes. The third gear must be secured to the shaft by tapping and placing a nut against it. The shaft protrudes out to hold the crank, which is locked in place the same way. However, there are 2.8mm and 3.2mm hole diameters available; all the 2.8mm holes are for tapping purposes, while others remain plain. Watch a video of the boat in action at https://youtu.be/MhlXEtJgdNg.