It is not hypocritical to defend and protect copyrights. This is a very important right in democratic regimes!
As I have already said, I am willing to carry out tests of various commercial and prototype propellers, I can advise on how to increase their efficiency, etc. And that is not hypocritical.
10k RPMs are not too high. For example, ship modellers sometimes use much higher speeds and do not need gearboxes either.
But who wants the transmission for the e-foil drive system, so letās install it. It only gets acceleration and can use a simple and cheap propeller. Like a fisherman somewhere on a pond.
You want to test others prototypes (which may or may not be protected designs), which easily gives you the ability to copy or incorporate their designs into your own if they are good, but are not willing to share your designs even if protected by copyright. That there is hypocritical!
If your designs are copyrighted, surely you want as many people as possible selling and using the propellers. So either the design is not proven or it is not being manufactured for some reason. So when will the props be available?
It can be said that his e-foil does work but he does not have very good parameters. Very good parameters can not be obtained with the propeller used by ordinary vessels.
Model ships have very different characteristics to efoil as they are very lightweight and as a result need way less torque to start moving. You simply canāt use the same motor and propeller principles.
A higher RPM motor with smaller prop also uses way more power and as a result is less efficient. With an efoil you wanāt to reduce power requirements as much as possible in order to fly as long as possible and increase manoeuvrability.
It does not matter if the engine has a 100% (or 90% or 80%) torque at the e-foil start, but it depends on whether the propeller is properly optimized to drive the motor at 50% of nominal speed (or 60 % etc).
As I have already said, I am willing to carry out tests of various commercial and prototype propellers, I can advise on how to increase their efficiency, etc.
I think this is a great idea but Iām not sure at the moment that 2,2 kW is enough to get on the foil. It probably is with a custom foil with a big surface area or a SUP foil for exemple.
From my point of view, Epoxying the motor is not the best way to go since itās pretty hard to do it properly and a lot can go wrong throughout the process. Also, I personally am alergic to Epoxy resin (Discovered it while epoxying the boardā¦).
So far Iām going on a 6384 motor, oil-cooled inside an aluminium tube sealed. The setup is really small in length ( 145mm long) and 70mm in diameter. The problem is the friction induces by the oil.
In my opinion, the best way to go would be to go for a smaller motor (maybe a 5070 one with 100Kv or lessif possible), mounted inside a 55mm tubeā¦ Cooling could probably be done via an aluminium plate linked both the the aluminium tube AND to the stator of the motor.
If cooling is OK, this setup would be super reliable, easy maintenance, low costs, low drag.
Nothing comes out of the back, but i see your point regarding getting to the circlip.
I guess the washer/screw solution in a slightly enlarged center hole could work well.
@jakebarnhill1 on my motor, the piece that centers the big bearing in the rotor, would come into contact with the stator if you donāt remove the small screws first.
So without circlip, iām afraid if the motor stops while youāre moving, the prop would be pulled the wrong way and youād loose you stator if the interference above doesnāt happen on your motorā¦
@Bender isnāt that what happen to you? missing circlip?
The problem with the circlip could be handled with a clamp ring or by having a watertight electric plug(s). The motor mounting plate screws are coming from the front and can be easily unscrewed. If we had a watertight plug inside the motor mount plate, the motor can be withdrawn straight to the back.
An alternative to watertight plug could be a watertight fixed coupling, but then you need to draw the flexible wires trough the mast to disassemble the circlip and maintain the bearings.
I have no experience with wires in mast, what do you think?
To be able to work on the motor without having to disconnect from the cables or move the cables inside the mast, i have a āservice loopā that hides inside the pod on the other side of the mast from where the wires comes out of the mastā¦ writing it, i realized how unclear it isā¦ iāll upload my post with a picture when i get home
Sorry, i cannot consider your special problems. Maybe you should wear gloves when dealing with epoxy. I barely had skin contact to epoxy, its ugly. Use Polyurethane or something else.
An oil filled can around the outrunner is too far away from direct cooling. It only opens new problems and solves none. You need a seal. You pollute the lake with oil. You pollute the oil with water. The motor pod is much bigger, inducing lots of drag. The aluminium tube causes eddy currents. The oil induces much more drag because of viscosity. I fear it will never work. Sorry to write this. I hope i can avoid great disappointment.
I agree, we are already having success with direct drives fully submerged in the water. Epoxy is not an issue, it can be applied by hand, then once itās set just sand it back so it doesnāt interfere with the magnets.
The bearings should be no issue as well, the stock bearings on my motors are like new after hours of use over 6 weeks. They are not stainless steel either. I didnāt even oil after each use, i just filled the area between the bearings where the shaft slides through the centre of the motor with grease, and the small supply of grease keeps them rust free and running smooth. I have re-packed it once only.
I wasnāt asking for any sort of help regarding the epoxy (And obviously I wore gloves at all times), sorry if I didnāt express myself properly.
Also Iām using 100% vegetal oil that wonāt damage anything AND am using dual Vring so that nothing can go out of the tube nor nothing can go in.
Regarding the induced drag, I did some measurments at maximum RPM (close to 4500 RPM):
Sealed mounted on, propeller spinning in the air: 530W
Same configuration but with the oil poured in: 700W.
If Iām not mistaken, being on the water wonāt affect the added power induced by the oil.
In my opinion, both have pros and cons. Trial this weekend, Iāll let you know how it goes.
Awesome keen to see how it goes! Why donāt you try automatic transmission fluid? it is very thin and this is why some e-bikers use it in their hub motors to dissipate heat from the stator to the rotor to shed more heat. Ive done this on my bike hub motor and can confirm that it doesnāt damage the motor in any way apart from making everything inside oily.