Hi Jezza
Where would I get one of these from?
Thanks.
I got that from a prop shop in the UK. Can’t remember the name now.
That’s the place. They make some awesome props.
Ordered one of those cleaver props from prop-shop (CRC/11013/3/LH/BR), thanks for the tip.
I only have 3d printed ones now so this’ll be my first real prop. Will hopefully arrive next week. will try it out and let you know if it’s any good for my setup.
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What motor you running? They designed to run between 7500-10000rpm. I know that bazaki on endless sphere managed to get 55kph on a surfboard with one so on an efoil it could be very interesting!
I’ve been too busy with other work over the last 4 months, but got some good stuff coming soon I hope.
I am interested in this also. How to mount? You use Flipsky 100kv? Looking forward to see some assembled pics and logs.
Regards!
80100 setup. Asked them to match it with my 12 mm axle. I have 130kV at 10s so only 5000rpm noload, guessing 4000 loaded…
Planning for 16s for next build so it’ll be a bit snappier then.
Got cleaver prop today, it’s beautiful but really small! I understand the rpm recommendation 
I’ll try it on 10s and see.
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This prop might be good to try on SSS56114 360kv direct drive 12S setup, resulting about 15K rpm with this prop (if torque will be enough) .
Check out this guy running high speed kayak on similar setup:
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15k is a lot. My 80100 motor is maxing out at 7-8krpm due to eddy current losses.
Is his duct available to buy? And where do I get such a prop, thanks
Yes, from Kenzen RC. https://www.kenzenrc.com/
Their presence is as old as the forum itsef: Search results for 'kenzen' - FOIL.zone
https://www.aliexpress.com/item/32272783458.html
They have interesting 3 and 4-blade CNCed alu propellers (120, 130 and 150mm diameter of various pitches ) that I’ve never seen tested on this forum:
3 blades: https://www.kenzenrc.com/productinfo/426431.html
4 blades: https://www.kenzenrc.com/productinfo/426439.html
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I get that the duct around the prop can help protect from weeds, Does it do anything to help with performance? I’m not concerned with weeds in the water I will be in… @SoEFoil @Antonbit and I’m open to others input.
Well it was my first time riding yesterday and fell over the board instead of with the board but if I wouldn’t have fallen in front of the mast I could have gone head first into the propeller had the duct not been there
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The duct is only there to protect from injury. There no performance benefit in the slightest and actually only a decrease in performance.
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Has anyone tried a really tight tolerance duct and propellor yet? I know in jet systems the tolerances are ridiculously small. A friend of mine is building jet drives for small boats and once there is a 0.3mm gap between impeller and nozzle the system starts to cavitate and either wear ring or impeller needs to be replaced.
The gap between my prop and duct is about 0.5mm. I had to put carbon around the duct to prevent it from deforming. The alu prop touched the inside of the 3d printed duct and took some material away without the enforcement. I also put carbon rods inside the struts. Now it works but I wouldn‘t make the gap smaller.
The topic hasn’t been properly investigated IMHO. People have understood that propellers need to be modified to match the motor/battery combo so in a near future, I hope that the duct/prop combo will be the centre of attention.
Theory is promising: many papers, patents and studies have announced a 10+% increase in performance with a properly designed shroud/duct with the appropriate airfoil section.
Practice has been disappointing so far:: the airfoil section of that HR or Rice Speed nozzle is not that clear. Removing the duct ensures a 10-15% speed increase because the right implementation is still to be found. A neutral duct (a duct that doesn’t degrade the free prop behaviour) hasn’t been found yet.
Hey @Guldsteen , you put a lot of attention designing your duct according to the airfoil sections documented in studies and theory: Guldsteen’s build - CAD, links and pictures - #6 by SoEFoil - Builds - FOIL.zone . How would you qualify your latest duct efficiency: positive (you’re gong faster), neutral (same speed) or negative (slower speed) ?
Rice Nozzle attempts on this forum: Search results for 'rice speed' - FOIL.zone
I don’t like that dude rambling and ranting way too much for ad revenue, plus he’s going to end up blowing both his motor and ESC in no time, and if that’s not scary enough, think about Li-po fire on his plastic kayak, considering he keeps using that high amp setup with a submerged, bare, fully exposed direct drive SSS inrunner, I did warn him though.