Thanks @tylerclark. There are still a few things to improve. I looped in Fusion expert @Taylor and we want to improve it more. Not sure if anyone tried the parametric prop yet. When changing the blade count the computer sits there for a minute, something in the model I set up in a non efficient way. Stay tuned.
Yeah, something like that would be interesting to take full advantage of your amp draw at the higher speeds
I run this propeller with a duct. I have two designs, one is a perpendicular hydrofoil (kort nozzle: i.e it does not taper in at the back like a traditional nozzle), this taper results in excessive drag. It is simply a aerofoil or hydrofoil profile which generates lift towards the propeller. I also have another design which is a pure foil (i.e. same shape on both surfaces) which also works. Both don’t seem to generate a lot of drag, however I haven’t had the guts to test it without it 
2 Likes
Nice!
I didn’t bother to reinvent the wheel with props because there are so many tried and true designs already. What I did was used this very simple calculator Vicprop - Prop Calculator for planing hulls to figure out what diameter and pitch I needed for my fat ass to scoot along at 25mph given the kW I have available and the rpm of the system. Then I found and downloaded a mercury racing propeller design (which was far to big) and simply scaled it down with CAD to the correct OD, made some modifications like the square prop shaft and a few other things. That’s it. Printed it in PC-Max and bam!
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This is awesome performance!Thanks for share!
But at 3500rmp on the prop,148mm dia and 200mm pitch with 26mph onboard this is no slip propeler 
,is this even possible? 
.
Didn’t understand you with the duct… do you have duct with airfoil and without any angle?
best regards!
Simon
guys maybe time to think in a complete different way? Put the propblade inside and the engine outside? Gives you incredible power and no sealing problems anymore…
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Personally I use a solas one
http://www.marineengine.com/newparts/part_details.php?pnum=SOL0001-073-06-P&ebcn
Yep, a rim driven thruster should work very well. Only challenge is to build it from scratch, with a decent budget.
Is this your design? Does it work with 3kw?
Cheers
@tunnelvision, I am very impressed that you got up to 26mph with that prop and with a duct. You said your CAD is available, you post a link to your prop and duct here? Thank you.
The square shaft is a good idea, especially for gear reduction high torque prop. The printed props may be not as strong.
This page has more ideas about alternative ways to connect shaft and hubs. https://www.stoffelpolygonsystems.com/
Probably this one scaled down 
2 Likes
Is anyone building jet drive (impeller) if so what have you come up with thus far?
I have found that impellers 50-80mm like 16,000 RPM and 16,000 is also the sweet spot for many motors for electrical efficiency. Im looking for some impeller designs and nozzle with diffuser to 3D print and test.
Hi!
I used solas prop in the begining… I had 300kv motor with 4:1gearbox 12s lipo and around 3300rmp unloaded. Speed was around 12-13mph-foiling.For me at 75kg was enough but my 100kg friend couldn’t get on the foil… I got around 35A…
best regards
Simon
Hello
Very interesting. You got only 36 amps???in cruise mode? It’s mean 4x12x36= only 1800w! That’s true?
My setying is 8s, direct drive and 130kv! What do you thing about?
Why do you change it?
I build 80mm jet with fully molded carbon fibre impeller at the beginning 
,but efficiency was too bad, I think it is very important (for classic jet) that the nozzle of the jet pushes water close to the air so the air can be soaked in to the steam(kinda mixture air-water). it seams weird but when water travel thru the air gets more kinetic energy- it can accelerate.Under the water there is no air after water leaving the nozzle so the acceleration is smaller…
I make classics jet-surf from it
https://instagram.com/p/BUrB5G0jHfv/
For foil I think proper propeller would be the best…
best regards
Simon
…when foiling. I changed it becouse with the duct was like 20%less power, even couldn’t get on the foil 
. Then @Hiorth send me his design and it worked pretty well!! thank you Nikolai!
Then I designed my own 3bladed kort, with blade area close to the Nikolais prop. So now I can play with different pitch and blade shape…
It would be really nice if you could run it direct-drive,but can be to much load for the motor…
simon
10 Likes
How did you make this? What Motor?
This might be the way to go… but sofar to expensive… We`ll see what future brings;-)