I recently saw this George Rickey sculpture at my local library branch.
The interesting thing is the way it moves. Its obviously 2 triangles
suspended in such a way as to move in the wind. There is a central
bearing at the top of the pole, allowing it to turn to face the wind
and the trinagles move horizontally. However, the traingles never seem
to tip completely over like you would expect them to. I watched it for
a long time and concluded the bottoms of the traingles are weighted
somehow to offset the balance, but at some point, I would expect the
tipping point or weight at the top cause it to tip over. Its made of
stainless plate welded to form square tubes that make up the triangles.
How do you think this done? Hopefully the pictures will be able to tell
the story of how it moves. His other pieces are also an elegant use of
material and balance. View my pics he

http://photos.yahoo.com/knucklehead1002002

-Mike

I viewed your pics with interest. It almost seems a physical impossibility
that they would ever turn completely over due to the way they are weighted.
I was wondering if they might be gear driven somehow and motors in there to
get them to turn. I cant imagine how turning the both of them into the wind
in any direction would ever allow them to catch enough wind to even stand up
straight from their axis point. They look too top heavy.


"mclorson" wrote in message
oups.com...
I recently saw this George Rickey sculpture at my local library branch.
The interesting thing is the way it moves. Its obviously 2 triangles
suspended in such a way as to move in the wind. There is a central
bearing at the top of the pole, allowing it to turn to face the wind
and the trinagles move horizontally. However, the traingles never seem
to tip completely over like you would expect them to. I watched it for
a long time and concluded the bottoms of the traingles are weighted
somehow to offset the balance, but at some point, I would expect the
tipping point or weight at the top cause it to tip over. Its made of
stainless plate welded to form square tubes that make up the triangles.
How do you think this done? Hopefully the pictures will be able to tell
the story of how it moves. His other pieces are also an elegant use of
material and balance. View my pics he

http://photos.yahoo.com/knucklehead1002002

-Mike

I haven't seen any of that series but I did help erect one of his spear
pieces at our local science museum. It was three 8' long tapered spikes
formed in stainless and mounted on a 12' pole with a pivoting top. The
spikes had universal joint mounts about 2' from the big end. The only limit
stops were to keep it from bumping into the support pole but otherwise could
swing freely. The bottom of each spike had just enough lead weight to hold
it vertical. The slightest pressure would send it spinning. In normal
winds the spikes will only go as far as the horizontal but they can rotate
360 degrees. I know this because I was standing at the base mounting the
title plate to the pole when the guy in the bucket who was giving it a final
polish bumped a spike and sent the tip flying about an inch away from my
face.

--
Glenn Ashmore

I'm building a 45' cutter in strip/composite. Watch my progress (or lack
there of) at: http://www.rutuonline.com
Shameless Commercial Division: http://www.spade-anchor-us.com

"mclorson" wrote in message
oups.com...
I recently saw this George Rickey sculpture at my local library branch.
The interesting thing is the way it moves. Its obviously 2 triangles
suspended in such a way as to move in the wind. There is a central
bearing at the top of the pole, allowing it to turn to face the wind
and the trinagles move horizontally. However, the traingles never seem
to tip completely over like you would expect them to. I watched it for
a long time and concluded the bottoms of the traingles are weighted
somehow to offset the balance, but at some point, I would expect the
tipping point or weight at the top cause it to tip over. Its made of
stainless plate welded to form square tubes that make up the triangles.
How do you think this done? Hopefully the pictures will be able to tell
the story of how it moves. His other pieces are also an elegant use of
material and balance. View my pics he

http://photos.yahoo.com/knucklehead1002002

-Mike

The lead weight would make sense. I noticed the pivot point of the
triangle is anchored from the very axis of the traingle and actually
extends toward the middle of the triangle. This would, I think, move
the center of gravity to a balnce point ...if the weight were heavy
enough. I don't know for sure, but I don't think there is anything
mechanical to offset the weight. Other than counterbalancing.
-Mike

hint "Two Open Triangles, Gyratory II Rickey's two wind driven
elements (geared down so that in high winds the parts are not
dangerous) provide an endless series of combined, almost dance like,
shapes and movements" ... If you look closely at the pictures, you
will notice that the edges are recessed and appear to be gear
connected (rack and pinion) to each other.

"mclorson" wrote in message
oups.com...
|I recently saw this George Rickey sculpture at my local library
branch.
| The interesting thing is the way it moves. Its obviously 2 triangles
| suspended in such a way as to move in the wind. There is a central
| bearing at the top of the pole, allowing it to turn to face the wind
| and the trinagles move horizontally. However, the traingles never
seem
| to tip completely over like you would expect them to. I watched it
for
| a long time and concluded the bottoms of the traingles are weighted
| somehow to offset the balance, but at some point, I would expect the
| tipping point or weight at the top cause it to tip over. Its made of
| stainless plate welded to form square tubes that make up the
triangles.
| How do you think this done? Hopefully the pictures will be able to
tell
| the story of how it moves. His other pieces are also an elegant use
of
| material and balance. View my pics he
|
| http://photos.yahoo.com/knucklehead1002002
|
| -Mike
|

hint "Two Open Triangles, Gyratory II Rickey's two wind driven
elements (geared down so that in high winds the parts are not
dangerous) provide an endless series of combined, almost dance like,
shapes and movements"

There are no gears that I was able to see close up. Even if so,
remarkable engineeering don't you think?

... If you look closely at the pictures, you
will notice that the edges are recessed and appear to be gear
connected (rack and pinion) to each other.

The triangles are not connected to each other.
There is a small lip around the entire outer surface where it appears
the exterior has been spot welded onto an internal frame
They move completely independant of each other. I'd like to know
more...where are you quoting from?
-Mike

mclorson wrote:
I recently saw this George Rickey sculpture at my local library branch.
The interesting thing is the way it moves. Its obviously 2 triangles
suspended in such a way as to move in the wind. There is a central
bearing at the top of the pole, allowing it to turn to face the wind
and the trinagles move horizontally. However, the traingles never seem
to tip completely over like you would expect them to. I watched it for
a long time and concluded the bottoms of the traingles are weighted
somehow to offset the balance, but at some point, I would expect the
tipping point or weight at the top cause it to tip over. Its made of
stainless plate welded to form square tubes that make up the triangles.
How do you think this done? Hopefully the pictures will be able to tell
the story of how it moves. His other pieces are also an elegant use of
material and balance. View my pics he

http://photos.yahoo.com/knucklehead1002002

-Mike



Since nobody mentioned "springs", I will...

But it probably is just plain old gravity.

I hope that the pivots are well designed remain mechanically sound as
they weather and wear. The artist/owners probably wouldn't want to
experience the gravity of the situation if one of those triangles went
sailing off into the breeze and landed in an occupied baby carriage.

Jeff

--
Jeffry Wisnia

(W1BSV + Brass Rat '57 EE)

"Truth exists; only falsehood has to be invented."

I agree with other posters that this is rather neat.

Figure it's just a matter of weighting the triangles properly
and setting the pivot points at or above the center of gravity.

The different edges of the triangles act as simple air foils
and cause the triangles to move relative to each other.

And the bicycle crank in the middle adds to the effect.

Not complex but VERY ingenious!

DOC



"mclorson" wrote in message
oups.com...
I recently saw this George Rickey sculpture at my local library branch.
The interesting thing is the way it moves. Its obviously 2 triangles
suspended in such a way as to move in the wind. There is a central
bearing at the top of the pole, allowing it to turn to face the wind
and the trinagles move horizontally. However, the traingles never seem
to tip completely over like you would expect them to. I watched it for
a long time and concluded the bottoms of the traingles are weighted
somehow to offset the balance, but at some point, I would expect the
tipping point or weight at the top cause it to tip over. Its made of
stainless plate welded to form square tubes that make up the triangles.
How do you think this done? Hopefully the pictures will be able to tell
the story of how it moves. His other pieces are also an elegant use of
material and balance. View my pics he

http://photos.yahoo.com/knucklehead1002002

-Mike

What appears to be a bicycle crank is really a flat level bar with the
axles mounted on each end opposing each other. My underneath angle for
taking the picture made it appear that way. Yeah, great stuff...I'm
drooling.
-M

Ah...

That guy needs to put a crank in there!!

Don't these artists know anything??
:-)oooooooo

DOC

"mclorson" wrote in message
oups.com...
What appears to be a bicycle crank is really a flat level bar with the
axles mounted on each end opposing each other. My underneath angle for
taking the picture made it appear that way. Yeah, great stuff...I'm
drooling.
-M