flutterby drive

[groverdamascus]

looking for some help with a new idea, an oscillating wind vane that drives an oscillating fish tail in the water. direct drive, one moving part! too good to be true, too simple to be new, I'm ready to begin the experiment but I'm thinking it's a good idea to research first (duh).
anyone ever seen such a thing?

[Guest625101138]

I do not believe it can be done with one moving part.

I expect that for any reasonable power level relative to the boat you will have nasty force couples to contend with.

For more meaningful assessment you would need to provide a sketch of what you have in mind.

Rick W.

[Kay9]

Some basic LAWS of physics start comming to mind real fast, that make me think this isnt likely to work.

Would like to see a drawing.

K9

[alan white]

Originally Posted by groverdamascus

looking for some help with a new idea, an oscillating wind vane that drives an oscillating fish tail in the water. direct drive, one moving part! too good to be true, too simple to be new, I'm ready to begin the experiment but I'm thinking it's a good idea to research first (duh).
anyone ever seen such a thing?

Yes, I know the concept. The upper (wind powered) part reciprocates by slinging a flag between two upright rods. The flag is longer (wider) than the distance between the rods. One of the rods is affixed to a pivot, which allows the other rod to rotate about the first rod 360 degrees.
The two rods are solidly connected together.
The whole assembly "waves" like a flag does, but with complete control, and the waving action causes the fixed rod to reciprocate. This in turn vertically connects to a semi-rigid fish-tail blade.
Orientation or indexing between the wind mill and the fish-tail is adjustable by a bevel gear pinion between two bevel ring gears. Allowing the pinion gear to rotate (by unlocking it) allows sailing at different points of sail.


Alan

[Tcubed]

Fascinating!

I have a sketch of this i drew in one of my sketch books of about twelve years ago. I had kind of forgotten about it and had no idea whether or not someone else had thought about it as well.

[alan white]

Originally Posted by Tcubed

Fascinating!

I have a sketch of this i drew in one of my sketch books of about twelve years ago. I had kind of forgotten about it and had no idea whether or not someone else had thought about it as well.

I built a prototype and it worked quite well. The flag can also orient to pump up and down to run an irrigation pump through a lifting and dropping rod.

[ancient kayaker]

Don't see why it shouldn't work. I built a kite when I was a kid using an old model plane wing that oscillated side-to-side, just to annoy the older guys in the model plane club: it worked on both counts!

I can see the up and down direction of oscillation would work on all points of sailing but I don't see a horizontal one working too well except upwind. Maybe I'm not visualizing what you guys are describing. Let's see pictures!

[alan white]

I've never applied my windmill design to boat propulsion. The importsant thing is that it doessn't matter whether the fish-tail propulsion blade or the wind mill end are horizontal or vertical. However, a reciprocating wind mill on a horizontal axis is simpler. With a horizontal axis, a rod is made to go up and down. The rig above orients to the wind, but always goes up and down.
The connecting rod can be connected to a sliding ring that allows 360 degree rotation of the wind mill.
The relative orientation of the wind to the boat direction can easily self-index so the boat control would simply be a matter of steering and nothing else.
I don't have a scanner hooked up right now unfortuinately. I may try to hook one up tomorriow.

[Guest625101138]

Originally Posted by alan white

I've never applied my windmill design to boat propulsion. The importsant thing is that it doessn't matter whether the fish-tail propulsion blade or the wind mill end are horizontal or vertical. However, a reciprocating wind mill on a horizontal axis is simpler. With a horizontal axis, a rod is made to go up and down. The rig above orients to the wind, but always goes up and down.
The connecting rod can be connected to a sliding ring that allows 360 degree rotation of the wind mill.
The relative orientation of the wind to the boat direction can easily self-index so the boat control would simply be a matter of steering and nothing else.
I don't have a scanner hooked up right now unfortuinately. I may try to hook one up tomorriow.

The original post stated ONE (1) moving part! This sounds like somewhat more. Still waiting to see a concept with one moving part.

Rick W

[alan white]

All I can imagine is a vertical axis windmill--- the kind with maybe four vanes. a vertical shaft down to prop in a tunnel drive that has a vertical turn in it, but the rpms would be way off without gearing.
I don't think it would make sense to limit the drive to one part except as an exercise resulting in a very very low efficiency.

[Tcubed]

Here are pictures of some sketches i made in 96. Excuse the terrible quality, almost all my stuff went underwater when one of my boats sank. I'll draw this out again so it's clearer soon.

Alan, i couldn't agree more. The first post described one moving part but i think that is quite unfeasible. A more realistic number is nearer half a dozen parts, which is still quite simple.

[alan white]

Hard to read those drawings, as you can imagine.
There are many methods by which a wind machine can propel a boat.
From a practical standpoint, the uses of any rotating or reciprocating system, no matter how many parts, will always be limited by the problem of large parts swinging or spinning around up there overhead.
Sails are limited to 3/4 of the compass in direction, but otherwise they are incredibly simple and trouble-free. They can be put in bags of all things, leaving little windage up otherwise.
Back to dreaming: The simplest system not using sails that I came up with was a horizontal axis pivot that hung a flag-like fabric area which caused an up and down pumping action. This was actually tested and worked well.
The up and down pumping caused a rod to go up and down exactly like an oil well. The application for marine propulsion might use a "whale-tail" part attached directly to the vertical rod.
The advantage is that the "sail", a rectangle of dacron, could be furled, leaving the frame alone just like a normal sailboat.
However, the drag component of such a rig would probably disqualify it from real use because of the difficulty in staying it----- and reefing presents even more problems.
I would like to understand what you've got there, but I can't understand the drawings. Not to complain--- haha--- I have NO drawings myself!

A.

[ancient kayaker]

Originally Posted by Rick Willoughby

The original post stated ONE (1) moving part! This sounds like somewhat more. Still waiting to see a concept with one moving part.

Rick W

Don't think it can be done if the objective is only one moving part. To get reciprocating motion from wind power needs two at least, the airfoil and a pivot attached to an arm with a pivot, not counting a mast to raise it to a useful hieght. At least the airfol could be rigidly attached to the hydrofoil qualifying as a single part. I am visualizing an arrangement similar to a very simple vane steering mechanism so the airfoil/hydrofoil can wave back and forth horizontally; vertical reciprocation would require more parts to link the airfoil and hydrofoil which could no longer be rigidly fastened together. Did Grover leave the building?

[Tcubed]

alan white's Avatar
alan white said<<<<<<<There are many methods by which a wind machine can propel a boat.
From a practical standpoint, the uses of any rotating or reciprocating system, no matter how many parts, will always be limited by the problem of large parts swinging or spinning around up there overhead.
Sails are limited to 3/4 of the compass in direction, but otherwise they are incredibly simple and trouble-free. They can be put in bags of all things, leaving little windage up otherwise.>>>>>>>

Exactly.
I guess what keeps us dreaming about these things is the notion of sailing at any point of sail and possibly even from within an enclosure just manipulating some levers and things. Kind of conjures up images of the mad inventor, doesn't it?..

[Tcubed]

Here is a bit better doodle i just drew of what i had in mind. This drawing is to illustrate nothing more than the basic aerodynamic part of the setup. The wing sail flaps back and forth within the 'yoke' which itself swings back and forth. The hole through which the sail goes is shaped such that the sail will automatically be angled and cambered at whatever it is designed for.

No doubt the least of all the problems would be a tremendous amount of noise. The cloth version i had thought of too but would no doubt be much less efficient. No doubt all these limitations passed through my mind and that is why there is only a couple of pages dedicated to this idea in my sketch books.

As a land based windmill system it is much more promising i think.

The inset diagram A is to show the yoke and the foil from above.