Propellers and Ducts


Show the propeller from several directions to make it easier to see. Only then will the propeller be easy to judge.


Please have a look here:

Question is, if outlet vanes could increase the efficiency. How could they be shaped?


Your setup looks great!

I plan to try the same setup as yours with different props and two motors I have powerglider 100kv and turnigy sk3 149kv ( with two blade prop - should be more efficient).
@PowerGlider, can you please share your enclosure and motor mount design, so I can try it ( also outlet vanes as well). I think outlet vanes should be thin and just straight ( as per your shared video and my personal investigation) probably motor enclosure supporters should be angled in opposite to rotating direction


I have ordered 100kV MP56115 inrunner motor with 14s 300A watercooled esc.
My setup: 12s 20Ah liion battery, direct drive, loaded rpm about 3500rpm. Target speed 35-40km/h (min 30km at first)
Could you suggest the prop for this setup?


To proksa1: In order to be able to select the correct propeller for the e-foil, you must first measure the drive torque (


I want to use it for old surfboard, not for efoil.


This principle is universal - it’s not only for e-foil, but also for surfboard and Titanic


You can leave the edges sharp!


I shared a link on another thread to a Free Impeller Design Software if you guys are interested: Jet Propulsion?


Currently exploring the different options for waterproofing my motor shaft with the printed housing. Will something as simple as a mechanical seal get the job done? Or even just a rotary shaft seal? Or will more drastic measure have to be taken?


Just for inspiration:

A guy build his own EDF blades from carbon fibre.


or :



i use this:


man these carbon guys are just sickly awesome! thanks for sharing!


Hey @WNT,
I want to try an old jetski impeller, what’s your take on that?
It’s a Skat-Trak USA 9-17


Any1 from America here who have heard about “Mokai kayak”? They used 7-8 hp IC 4 stroke engine with a jet system. Not a racer but imo not a slug at all… Found some images (mostly youtube diy repair videos) of its impeller, looked like bigger size with my blind hawk eyes (80-100mm?).

Company is based in NY. Nothnig fancy, just some more given numbers and performance.



HI VeFoil,
Do you have results on your 220KV new inrunner motor and 80mm duct? What was the pitch most efficient in this case? I appreciate if you can share your measurements with this duct.


Hi @tunnelvision, Can you please share again your prop and duct design? The dropbox link is expired and doesnt exist anymore.


I planning to use that motor but still dont know how to design prop with javaprop…really need help now