X1AaronW

Im planning to build a sub from pvc pipe roughly 24in long with a 2in i.d. it will be powered by a 36mm diameter x 60mm long 2200kv brushless motor. Long story short; im looking for speed. What kind of prop should I use?

Got RPM

First off, what voltage? Regardless, the Kv is too high for a fully submerged prop if you want any run time. You will want a prop about 1.5" in diameter with no more than 2" of pitch. Less would be better. On 2S a Kv of 700-800 would be plenty, otherwise you will draw way too many amps and overheat the motor and ESC. On 4S, 300-400 Kv should be close, too much and you will overheat. Run time will still be limited wit the size of cells you could fit in that tiny hull.

It takes a huge amount of power to move a fully submerged sub rapidly, particularly if it is not well streamlined with a tapered tail. Five mph is almost 8 feet per second and would be tough to achieve on a small boat like the one you propose. What speed do you want?



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X1AaronW

Forgive my level of optimism. I have zero experience In This. My design has changed. Same motor but hull size is 3in x 16in not inclincluding the sonar cone or tail section. The esc is 95A battery is 7.2v 5000mah. Im gonna make it as stream line as possible by using a large easter egg as the the mold for the sonar cone and im still working on a mold for the tail section but im thinking of making it to where the prop sits inside the tail section in a way that works it works like a jet drive and water is sucked in through 2 vents located just behind the prop. After some research I found that the prop recommend is a 40mm x 2.198 pitch. I realized that the prop size is for boats not subs. Looking for 10 mph but if I can get more you bet your sweet ass im going for lol!