Yes, you’re right, creative activity is very fun for me and most forum members. However, it took me about 15 years to fully understand the hydrodynamic issues of propellers, so I am now concentrating all future creative activity on propellers, wings, etc.
All things with dynamics in name are hard to understand 
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Im read some stuff about propeller but didnt eaven scratched sufrace of problematics…
So if you have good understanding of propeller mabye you can give me advice what could i try to use for 4800rpm that my setup have…
If you insist, then design and build a v1 propeller with only two blades. This has the following advantages (over a three-bladed propeller): less likelihood of ESC damage, cheaper and faster to manufacture, and easier to balance. During the first test, you can easily identify any shortcomings (e.g. low thrust) so that you can then design and manufacture a propeller in 1.1. You repeat all this until you have the experience to design and manufacture a propeller with three blades, which gives you the only extra advantage - more e-foil speed.
You have no show any Prop, what you have designed 
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Just a thought: Do we need to balance printed props? I understand it is important for air props or heavier aluminum props. But running in water 60-90 g prop…I am not so sure. Did anybody feel the difference riding balanced and unbalanced props?
Good question…
Printed props are so light that balancing maby dont have that big impact…
I have tryed few printed props on my buld and didnt notice any vibrations, all unbalanced.
A propeller imbalance may not be reflected in the selection of the entire e-foil. However, shaft run-out will definitely occur, resulting in reduced bearing life. Static balancing is therefore important for any rotor, especially one with a speed of 5000 rpm. Static balancing of the propeller is very easy.
However, every DIY propeller should be dynamically balanced. If it is not dynamically and statically balanced, shaft run-out can increase dramatically. This then results in an even faster reduction in bearing life.
On my new Flite propeller, I found a static unbalance error of about 0.150 g. Although this is negligible, I will remove this error as it is very easy for me to do.
Additionally, on my new APS 63100 140 kV motor, I found that it is recessing the rotor shroud. The fault is due to the shaft hole not being exactly on the rotor axis. If I don’t correct this error, it too will result in shortened bearing life.
It also contributes significantly to shortened bearing life if there are only radial bearings on the shaft (motor or gearbox).
Partial damage to the bearings will eventually start to damage the motor shaft seal (inrunner type), resulting in water ingress sooner or later.
Therefore, as a general rule, any cause of run-out should be rectified as soon as possible.
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Few of my new designs…
If anyone needs 130mm diameter cca 130mm pitch propellers.
https://drive.google.com/file/d/1xsMq4ilqDScm3TrDbWMS9Vfmk8fixIU3/view?usp=sharing
https://drive.google.com/file/d/1xsMq4ilqDScm3TrDbWMS9Vfmk8fixIU3/view?usp=sharing
https://drive.google.com/file/d/1DXhQB1gV83bOrD52wPuCC9JOTfaJD_go/view?usp=sharing
https://drive.google.com/file/d/1imXtr2Q1cTfIjoFxfalZzuhh3goj52wX/view?usp=sharing
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A long time ago, I had the idea of reinforcing my propeller with epoxy and vacuum. As the sealing was not very effective, I did not dig enough to see if it is useless or effective.
Yesterday I received some sealing bags for the 3d spools and tried again. Unfortunately the bags are not ultra thin and it will leave some marks when the epoxy dries.
I tried on a prop without epoxy just to see. And I was quite surprise to see water coming out from the prop… This prop was out from water since 2 months!!! So I do believe that if I can pull out water I can push in some epoxy!
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How did your sharrow-style looped propellor work out, in testing/durability/power usage?
To be honest I have not tested it yet. I think it will not hold up. Its ABS covered with epoxy. I should try anyway. I have shared the file with another person from the community recently. Maybe we will see some results there. I have concentrated on another prop which I am really happy with actually. Base design is also from this forum. I just made a stainless folding version of it with some minor mods. At least with my 65163 100kv setup this prop propelling me a little faster then with my FR props with different pitches. But I cant compare currents from my ESC.
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Beautiful propeller, maybe the first e-foil propeller made from metal on a commercial 3D printer. How much did you pay to print the propeller?
Well it was probably done on a commercial printer but in a non-commercial surrounding i.e. University. Therefore it was only material cost for powder and gas. The rest was understood as practicing. At least for once. But maybe the next step would be printing with steel filament ultrafuse 316L for example. At sculpteo it would be around 50$ per blade. Hub could be probably done with a good reinforced filament. Or what I am looking into next to print the hub with internal lattice structure and then filling it with some epoxy and fibres.
Thanks, it’s all interesting information.
So it seems that the shape of the folding blades is a bit better than the fixed blades of the FR propellers (both Flite and Manta). However, to confirm this, it would be useful to measure the current and rpm.
Thanks for sharing! Its working perfect with my pacificmeister-build! Miles better then the original prop with duct.
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Hi, i share this prop 133mmx256mm. https://grabcad.com/library/propeller-133mmx256mm-1 .I hope it’s useful.
Your prop 130mm with 10mm shaft
How do you block the pop in rotation ? Correct me if I’m wrong but for our use, I suspect the propeller hub diameter must not be too small with respect to the motor OD (65mm) in order not to mask too much propeller blade surface which becomes ineffective.
Hi, just sharing my own version of a toroidal prop like the sharrow.
Would appreciate any feedback
https://grabcad.com/library/toroidal-fan-blade-1
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For anyone interested, I can cast your prop design in aluminum/bronze for a long lasting strong prop!
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