zlacker

I really didn't grasp the size of that drone. It is not a little model boat, it is a ship. This video shows it being launched, and includes images of what it looks like:

https://www.youtube.com/watch?v=gJ-uYy9Ap8A

>>Joachi+(OP)
That's a larger model, this is the earlier Saildrone Explorer mentioned in that video. The vessel they are launching is 72 feet long, this one is 23 feet. So not a model boat, but not large either.

>>ezzaf+T
Could somebody please TL;DR the wing design (of the big boat) for me? The one with the additional extra wing?

>>fho+C1
The hurricane wing? It's smaller.

https://www.saildrone.com/news/tropical-atlantic-hurricane-m...

>>maxeri+C2
Ah ok ... no I was asking about the full size wing with that second wing attached to it.

>>fho+z3
Think it's like an elevator on airplane controls the angle of the big one.

Easier to rotate the wing than a motor at the root of the big wing.

>>jcun41+ym
Ooooh ... smart! Now ... I wonder if I can do the same thing for my 3D printed (hobby-) VAWTs!

>>fho+Dt
I think those have some kind of centrifugal pitch control with a linkage (based on RPM), might have to look at existing designs.

There are some helicopter blades that have this same idea, a little moving thing to control the pitch of the rotor over a swash plate

>>fho+C1
It's a self trimming wingsail. Its only purpose is to maintain the angle of attack of the main wing, much like how a horizontal stabilizer works on an airplane.

Personally I think it is something that is brilliant, and it is actually the primary feature that enables autonomous operation as a drone. There are no halyards or sheets, no ropes anywhere. All you have to do is maintain an angle of attack relative to the wind, and you have propulsion.

BTW, the founder holds the wind propulsion land speed record, and the wing design for this is an evolution of that design. When you're moving at 4 times the wind speed, no human can possibly keep up with the continuous trimming demands of a sail. This design does it perfectly, and at an overall reduction in total complexity.

>>jcun41+Rt
Controlling the pitch of the blades is how most helicopters work.

>>ezzaf+T
Nice, I had seen the Explorer models a while back and rather liked the work they were doing, it's great to see they are progressing and making larger ones.

>>rkager+A31
Probably wasn't clear above, I'm saying they weren't using a swashplate (most helicopters) they were using this little tiny tab attached to the rotor that could be controlled.

This thing on kman kmax https://gallery.vtol.org/images/2017/08/15/kmaxServoFlap.jpg

info https://www.helis.com/howflies/servo.php

>>ezzaf+T
The house I grew up in, in the US, was 23 feet wide. And globally speaking, that's a big house. So it ain't small, either.

>>Joachi+(OP)
Some smaller sizes ones shown here: https://youtu.be/ugDnC0iidL4?t=227

>>jcun41+Rt
That's a safety feature as much as it is an efficiency feature, it allows you to safely furl the blades when you are overspeeding, you can't rely on anything that isn't directly connected to the rotor base because it might be jammed, damaged, out of power or missing entirely. The blades governing themselves is the ideal, the linkage is there for synchronization and balance purposes only.

>>rkager+A31
Yes, but that's using an external actuator, rather than weights that pull the blades to their new angle.

>>jcun41+fa1
Oh neat! Thanks for educating me.

>>Joachi+(OP)
This 2020 video shows a fleet of their "smaller" models under test in Hawaii: https://www.youtube.com/watch?v=RvXq4n2aVh8