Re: lazy susan type bearing? thrust bearing?
 

I expect for the turbine blades to use two rectangular sheets of aluminum sheet metal. Each will be about 24" by 36" and will have a slot cut at its mid point that goes about halfway through. I'll join them together by sliding one sheet into the other's slot and vice versa. It's kind of like the box dividers inside a case of wine. I'm sure there's a more classic example of this join but I can't think of it just now.

Additionally the sheet metal will be hammered with a rubber mallet into a curved shape which should provide some additional stability against horizontal forces.

The sheets will not be connected to a shaft at all but only to the rotating wooden turntable via L-brackets. I'll be depending on the inherent rigidity of the metal augmented by the slot join and the curvature of the metal.

jspatz, the pulley hub seems pretty good to me. The thickness of the pulley plus the set screw hub is probably about an inch. It does spin very evenly. Also, I haven't seen an Andymark hub with a 1/2" round bore without a key notch. If there is one, it might be good to have. There are also die-cast hubs available from Chicago Die Casting (see attached document). Not yet sure where to buy them.

Re: lazy susan type bearing? thrust bearing?
 

Hammered into a curved shape? That will give pretty bumpy results. A roll-forming method over a round form would give a much smoother result. Anyway, regarding stiffening the outer edge without any other support...putting a slight verticle bend (or "break") near the outer edge of each vane will greatly stiffen the end and make it rigid. Just curious how are you attaching the vanes to the wood base? Leaving several tabs of material on the bottom edge of the vanes, then bending them at a right angle to create mounting tabs would be one method.

You realize of course that you are going to owe us all some photos of this thing when you are finished with it.

Re: lazy susan type bearing? thrust bearing?
 

I have very good news! I asked my carpenter buddy to come over last night and we cut some 2x4s and assembled a turntable using the roller thrust bearing, the flanged bearing, a washer, the 1' shaft, a shaft collar, a thin plywood turntable, and one of the bronze bushings. It was a pain to align everything properly and get it all level, but it totally worked. I can set the thing spinning quickly with a single finger and it'll keep spinning. My girlfriend timed it spinning 4 minutes and 15 seconds from an initial impulse. Totally, completely low-friction. In fact, I can just blow on the wooden turntable and it'll move. I consider this a triumph.

I bought some 1" plastic tubing as a way to keep the dust and elements out of the thrust bearing. I'll cut off a tiny bit and drop it around the thrust bearing.

jspatz, i've been reading about roll forming in the interwebs and I think you might be right. Trying to picture appropriate curved surfaces -- especially the concave one.

Yes of course I'll be posting pictures. I owe you guys.

Re: lazy susan type bearing? thrust bearing?
 

Sorry to have been gone so long (although it's probably a relief to you guys). I assembled the VAWT part -- or at least a temporary version of it. It passed the goal I had set, namely that it would turn in the presence of an ordinary electric fan.

http://vimeo.com/16100233

As you can see, the turntable is not exactly perfect but I think it might be good enough for the time being. I'll be attaching the speed reducer and the chimes before too long.

Re: lazy susan type bearing? thrust bearing?
 

Did you mean to password protect the video? I'm unable to watch it.

Re: lazy susan type bearing? thrust bearing?
 

oops. i had the wrong link. try again? it should work now.

Re: lazy susan type bearing? thrust bearing?
 

Well done!

Re: lazy susan type bearing? thrust bearing?
 

Nice.

Re: lazy susan type bearing? thrust bearing?
 

Cool! The vane is MUCH taller than I pictured when we were conversing about bearing methods. Now that I see the thing, its more like a tall rotating cylinder rather than a flat platen. Given this, I would change my advice about how to mount it. Those vanes are pretty tall to be unsupported at the top. Is there any reason there could not be another plate on top, forming a tall sandwich that holds the vanes securely? Then I would put another bearing on top so the cylinder is rotating between a top and bottom bearing. This way the turbine is firmly supported from wind side-load with widely spaced bearings, no cantilevered load above the bearings. In other words, a bearing above and below the turbine, rather than two bearings below the turbine trying to cantilever it. Would require another hub on top. Bottom shaft would protrude through the bottom bearing to your gearbox.

Re: lazy susan type bearing? thrust bearing?
 

Savonius rotor turbines generally have top and bottom plates and a gap in the middle.

Re: lazy susan type bearing? thrust bearing?
 

Bingo.

Re: lazy susan type bearing? thrust bearing?
 

I'm back for more effort on this music contraption if anyone still has any interest.

I'm grateful for the diagrams and suggestions about the VAWT blade shape and mounting scheme, but I am happy enough with the VAWT for now to move to the next stage -- namely applying the power from the vawt to the turning of a drum which will strike chimes.

To that end, I ordered some stuff from SDP/SI:
* GT2 (3mm) Pitch, 60 Teeth, Polycarbonate Timing Pulley With Aluminum Insert to connect to my 1/2 inch VAWT shaft
* Speed Reducer, Size 42, 30:1 Gear Ratio to "gear up" to give the VAWT a substantial power advantage for turning the music box drum while at the same time slowing the drum rotation speed to something suitable for a short tune
* GT2 (3mm) Pitch, 48 Teeth, Polycarbonate timing pulley to connect to the 6mm speed reducer shaft
* GT2 (3mm) Pitch, 207 Teeth,9 mm(.354) Wide Neoprene Belt to connect the two pulleys so the VAWT supplies power to the speed reducer.

The reason for the pulleys rather than a rigid coupling is that the speed reducer is metric (6mm) and the VAWT shaft is imperial (0.5 inch). I was also thinking -- perhaps wrongly -- that having the shaft of the drum offset from the shaft of the VAWT might allow some flexibility when trying to mount the music drum.

I'll also probably need the following:
* 6mm shaft for the music box drum
* hub(2) to connect 6mm shaft to the music box drum
* bearings or bushings to support the music box drum
* shaft coupling to connect the music box drum to the speed reducer.

I'm still unsure of the dimensions required of the music box drum, but I've got a 14" diameter cardboard tube (some kind of storage tube) for the music box drum. This should be workable -- I can screw or hammer pins into it which can act as the pluckers for my chimes. If you open any music box, you'll see the drum I'm talking about it. It plucks the little chimes. This height of this drum (the length from hub to hub) will be determined by the number of notes required for my song. I'm still mulling that over. Leaning toward a minimalist arpeggio a la Philip Glass.

As for the geometry of drum vs. VAWT, I'm thinking the drum should be mounted below the VAWT so as not to impede air flow. This may require some modifications to my VAWT chassis to elevate the VAWT.

Any thoughts or commentary are quite welcome.

Re: lazy susan type bearing? thrust bearing?
 

I would suggest a flywheel and governor to keep the speed constant and less dependent on the wind, otherwise, you seem to be on the right track.

Re: lazy susan type bearing? thrust bearing?
 

The VAWT turntable and blades seem to have plenty of intertia to keep speed steady. If anything, I'm a bit worried about the wind being string enough to get the beast turning.

connecting the 'plucker drum'
 

OK I ordered a couple of plastic timing pulleys, a timing belt, and a speed reducer so that I can deliver power from the VAWT shaft to the speed reducer. Ignoring for a moment that the speed reducer has a 4mm shaft and not a 6mm shaft, I'm wondering how to mount it so that
* the timing belt can be tightened and/or removed if necessary..this makes me think that either the VAWT or the 'plucker drum' mounting point must be moveable to take up the slack in the belt. Either that or a roller of some kind.
* the square shaft on the bottom of the speed reducer (see attached image) sticks out far enough from whatever it is mounted on to couple with the hub on the plucker drum
* The vertical placement of the plucker drum (and thus the speed reducer) is such that the belt connecting to the VAWT is sufficiently level for effective power transmission.

I'm also wondering a couple of other things:
* What kind of parts must one get to mount a roller? It needs a shaft...does it also need bearings or hubs, etc.? Seems kinda pricey for just a roller.
* Is the speed reducer (with puny 4mm shaft) sufficiently strong to drive the plucker drum? Its Maximum momentary torque is .1 (.90) N.m (lb.in.). The plucker drum will have pins that must displace a plastic tab with a screw in it -- not a lot of force. I suppose I need a diagram for this.:confused:
* What sort of coupling works well for a flat shaft end like the one on my speed reducer (see picture). Is a hub with set screw ok? Or do I need some kind of socket to couple with it?

My plucker drum is a rigid piece of cardboard tubing (for shipping i think) that is about 14.5 inches in diameter and about 2 feet high. I'm imagining I'll need a thrust bearing and/or bushing setup to mount it so that it rotates freely.

What I'm having trouble picturing is how to couple my speed reducer to the top of the plucker drum given all my other constraints.