Jet powered model boat (inspired in NQD)

thingiverse

I've seen many videos of people upgrading their powerplant with an NQD and building a fun model boat. I wanted to do the same but couldn't find the right model at a price I was willing to pay. So, I decided to design my own jetboat from scratch. You can see one of my previous projects on Thingiverse (http://www.thingiverse.com/thing:1141731) - it's a propeller-powered boat that runs smoothly and is quite cheap in its current configuration. However, it lacks agility, so building a jetdrive was the next logical step. My powerplant consists of: * Mabuchi 540 motor (4.5 euros if you buy three) * 3.175 to 4 mm coupling * DC ESC * 3S 220mAh LiPO battery * 9 gram servo I estimate that building a jetdrive boat with these components should cost under 30 euros. You can see the boat in action on YouTube (https://youtu.be/vU8ZhXroyTs). For the hull, I used PVC foam and a lot of hot glue - you can buy it in sheets for 5 euros per square meter. I don't have plans because I built it by hand. The shaft is made from 4 mm inoxsteel rod, which you can find at most hardware stores. When printing the housing, I recommend smoothing the inner surface with sandpaper and acetone (I printed mine in ABS). Inside the housing, I used M4 nuts drilled with a 4mm - 4.2mm drillbit as bushings. To connect the servo to the jet drive, I used hot glue and one of the arms that comes with the servo, gluing it to the top screw hole and connecting it to the servo with a 1 mm rod. I used M3 screws throughout, except for the ones holding the turning part, which are wood screws with an exterior diameter of 3.5 mm.