Crazy idea, please kill it before it is born, please


Crazy idea, please kill it before it is born, i need to let my brain think about something else.
The idea is simple: Just think about a classic aeroplane.
In front, propeller near motor, front wing over motor, fusulage and rear wing.
The duct must be redesign or flipt, or ringed. This “plane” must be mounted at the end of the mast, and the body has to be somewhat tubeish. There must be some fundamentally wrong with my thinking, please tell me why, i am learning :sweat_smile: See my beautiful CAD work, lots of hours :roll_eyes:


I would say there is nothing wrong with your idea. It should work.

The thing is, how does it solve the specific problems we have (cooling, waterproofnes , …). And where do you want to start and what is your goal?

Right now the classic approach of fitting a motor to an existing foil seems to be tho most promising way for the average DIY person because you have to engineer less parts.


I think the theory is solid, but it has not been built like that before. I think that is because of a gereral fear that having the prop in front increases the risk of foreign object damage. Both to the prop and to the foreign object :sweat_smile:.


Thanks @PB1 for not killing the idea(i think).:disappointed_relieved:

The thing is, how does it solve the specific problems we have (cooling, waterproofnes , …)?
It does not solve any of those problems, but maybe a couple:

  1. We dont have to solve long shaft problem, because the motor and prop is very close. I have seen Pasificmeister had some problem with this, and had to move bearings to solve it.

  2. I see some safety benefits, because the prop is close to the big front wing(horizontal) and the mast(vertical).

  3. Maybe better environment for the prop, no “turbulence”.

  4. Maybe it will give us more stability and higher speed, because the prop pushes mutch more water over the front wing and create more lift, and then we can use smaller wing, and that will give us higher speed( i hope).

  5. More flexibility to the length of the fuselage, and shape.

And where do you want to start and what is your goal?
I was so inspired by Pasificmeister, i did not comment on his Youtube vids, and when he started this community, i was just reading, but insted of just reading and “stealing” i was inspired to share some ideas and resource Youtube… I son find out that a wing is not just a wing and so on. I like the many approaches of efoil. And all i want to do is to
contribute in my small way. I have not bought or built anything jet, i am
waiting until it boils down to a few ways of making an efoil. I hope this is ok :smiley:


Hey Flex, great to see you brainstorming here. I am not an avionics or hydrodynamics expert but this is what I am reading about pusher vs tractor:

  • Performance-wise, a pusher is theoretically better. This is because the high velocity propwash isn’t scrubbing over the fuselage or wing, introducing more drag (or “negative thrust” if you like).
  • Conversely, a tractor’s propwash is always creating extra drag over downstream surfaces - more drag than if those surfaces simply were scrubbed by the plane’s airspeed.
  • Cooling is a reason to go to tractor setups for airplanes, not an issue for us here.
  • Keeping the prop further away from the ground during takeoff/landing and not have dirt kicked up into it by the tires is another reason for airplanes choosing tractor config. Should not really be an issue for us.

Regarding your point #1, the shaft setup will be similar regardless direction (except you can leave out the little thrust bearing), everything is kept as short as possible, length determined by coupler and 2 shaft seals and now the additional bearing. Goal is always to have the prop as close to the gearbox (or motor for direct drive) as possible.

So from what I have learned so far I think we are on a good path with pusher setups. But I love crazy ideas and please don’t be discouraged to give it a try. Lot’s of crazy ideas here and we might find out something new. That’s what keeps innovation moving forward :slight_smile:


@pacificmeister thank you for your input.
Now i can bury it(RIP) :relaxed:
The god thing, is now i(we) know what not spending time on, there is some value in that too :smiley:
Thanks again for the explanation :star_struck:



@Flo, Yes, and a bunch more wrong with the idea, thanks tho :smile:


These guys use a prop on the front. Interesting design.

I would think this to be a safer way to do it. You are less likely to get your leg/foot trapped.


And no duct/shroud…


@Dirkdiggler, dam you i was just done mourn the idea :rofl::joy:
Good eye tho :smile:
I think there is many questions and ways to go, thanks :smile:


Just perfect for when your foot comes off the pedal and straight into the prop :smiley:


@Jezza :joy::rofl::joy::joy:


I bet there is one, they only took it off for demonstration purposes. That thing looks like they put a ton of resources into the design. It looks so weird, that they almost certainly must have done a lot of computer simulations.


I think they modified the Aquaskipper foil design for their use. Obviously not meant for high speed use.

I’m sure they use a shroud or something normally. Pedal slippage would be a problem without. Still probably two feet away and by then I’d imagine the prop not spinning anymore. For our purposes though, it would be much harder to get in contact with the prop as you are most likely to fall off the back and push your legs forward. This way you’d likely just kick the back of the foil - which in itself could be a serious hazard. My wife has tons of experience with people using the old Airchair foils and having to be stitched up from the gashes. I had to do some sweet talking to her to let me even try the foilboard, not to mention even bring it on the boat. It goes right back in the bag as soon as I am done so no one gets hurt.


One really good reason for a puller is that if you are stalling, you have the engine wash airflow to keep control surfaces out of stall.

In an aircraft, once you have stalled your control surfaces, ailerons, rudder, elevator, etc, you are at the exclusive mercy of gravity and God.

So this is going to be useful if your efoil has controllable surfaces. I’m yet to see one. the manta5 has the surface follower way forward and would not see an advantage IMO.