I’ve continued to dabble on my efoil project in pretty limited free time, but figured I’d share my latest with this group and see if I can get good advice. (Apparently I’ve been at this sideproject for almost 4 years now… Boris eFoil attempt: planing but not flying)
My build is pretty similar to the latest from the above thread with the exception of a new front wing. I wanted to make as few changes as possible and felt the front wing upgrade could really help and so got the Naish HA 1840 (wingspan 112cm) which is almost 2x my previous wing and 50% more surface area.
After some weird shit with my electronics (absolute current limits were too low, kept getting FAULT_CODE_ABS_OVER_CURRENT until reprogramming the VESC on the water and setting limit to 300A), I was able to fly, but only briefly.
I’m actually able to get up on the wing at about 8-9 mph. It feels easier to do if I’m turning though… could it be that there’s a meniscus thing at the bottom of the board keeping it attached to the water?
Here’s the approach:
Get to 50% duty cycle with weight shifted somewhat forward
Shift weight a bit backwards to increase lift and get up on the wing
Try to find a balance between too much back and too much forward
(I keep falling back forward…)
I’m definitely up on the wing, but then quickly lose balance typically maybe I’m just the throttling too much at that point out of fear. And then what happens is the board kind of falls back down into the water.
At this point I think I’m suffering from lack of skill or lack of courage, but an alternative is that my board is too long, or the wing is too far towards the back. The Lift foil has its wing at the midline of the board. My board has its wing very far back, probably 1/5 of the way.
Think of the physics of that “flying”. Draw some vectors… The front wing pushes UP depending on the speed. But it is UP relative to itself, and result depends on arm-to- center-of-masses, and the board has to be almost horizontal in order to fly horizontally - so you have to compensate for that push-up-over-long-arm-to-center . In reality, it is not static, always going +/- up-down 1-5% - just as a person standing upright on land is NOT static, as we humans are not horses, we tilt forward/backward all the time subconsciously, and when moving forward, we are tilting forward). So it needs enough speed, and proper direction.
Move your whole body forward, maybe 5-10 cm (approximately, assuming sizes from the image). Then tilting forward or backward to get those +/- up/downs. Of course, how much speed is “enough”, depends on: wing/s area, your body weight, machine weight, waves-or-not, etc and only for higher speeds, rear wing angle. The faster the moving, more forward one has to stay.
When making turns, the physics is similar same BUT the wing’s UP is not anymore aligned with gravity’s UP, so anti-gravity component is lower, so one has to move backward a bit, or the nose will go under…
Keeping horizontal, accelerate until it starts to glide… then small shake will unglue and go flying… but KEEP horizontal because the jump in speed from glued-gliding to unglued-flying is sharp/harsh and you have to be prepared…
btw Fliteboard’s mast is more-or-less in same placement near the back. And yes, water is like glue… difficult to unglue But, then, once flying, with enough skill you can go down to ridiculously low speeds and still fly - e.g. 11-13km/h for Fliteboard’s Race wings that will not start flying before 20-25km/h - for my body’s 65kg.
Hi! Try moving the mast closer to the center of the board.
I had a similar problem, I moved it forward a few centimeters and watched how the board behaved.
As a result, I moved the mast 12 centimeter from the original installation location.
I would rather say that mast location only matters on boards that dont have a flat foil mount area. Once flying the board might as well be a chicken sandwich as long as it’s flat and stiff, the foot position relative to the foil is what matters (and the foil and stab)
But, then, once flying, with enough skill you can go down to ridiculously low speeds and still fly - e.g. 11-13km/h for Fliteboard’s Race wings that will not start flying before 20-25km/h - for my body’s 65kg.