Relocation and Updates

Matt and Bob painted the turbine a few weeks ago to protect it from the elements. It looks immaculate. I have since moved to Boston after graduating this June, but progress is steadily being made on the turbine. The folks from Patagonia contacted us about applying for one of their Environmental Grants. More news about that should be coming soon.

We were also contacted by Peacepoint TV about filming the turbine for a show they're doing on the Science channel. We'll see what happens.

Below are some pictures of Bob and Matt moving the turbine across the Midway.


Bob with the turbine in front of the SSA.


Rolling down Ellis Ave.


In front of the Admin Building.


Standing in front of its new (temporary) home.


Testing the winds on the roof of the parking garage.

It's Alive! (Rotor Assemblage 3)

Matt and I worked all day today to put the Lexan pieces on the ribs. Take a look at this video to see the turbine spin.


Taking a break after finishing half of the helix.


The process.

Rotor Assemblage 2

On Sunday we cut our sheet of Lexan into six pieces - two pieces short of what we need. These pieces fill the spaces between the ribs and will allow the turbine to catch the wind, like a sail. Bob finished drilling the holes in the shaft and we started to bolt the ribs on the next day. I ordered a few more pieces of Lexan for the remaining pieces and to make covers to protect against rain.


Jordan cutting one of the curved Lexan pieces.


Bob at the mill.


Putting the rotor together.

Rotor Assemblage 1

We did a lot of work on the turbine today. This morning, Clay welded a few strips onto the bearing supprts. The turbine shaft will pass through the hole in the picture once the bearings are mounted.

Later on, Matt met me at Midway Studio to haul some items over to Bob at the CIS building. Matt came up with an ingenious way of transporting the 90 lb. flywheel, borrowing from the classic game of his youth, hoop stick. By the end of the night, Bob had made 80% of the holes on the turbine shaft, taught me how to use the mill, and made the two other shafts.


Strips.


The first of the rib assemblies to be bolted onto the shaft.


Bob with mill and rotor.


Matt cleaned up the flywheel.

Roofs

On Wednesday I took a tour of the three candidate roofs with Mike from facilities.


On Kersten's roof, next to the scope.


From the roof of Hinds, looking down on Crerar.


From the roof of Crerar, looking at Hinds.

Each had its advantages and disadvantages, so I'm not sure which building would be best.

Ribs

Dan Stearns from University Theater did a beautiful job welding the rib sections together on Tuesday. These 5 sections will be separated on the turbine shaft by 1.5 feet, which gives us the desired 6 foot total height. Each section will be offset 45 degrees from the previous one, which results in a helix. The ribs will act as a frame to support the lexan scoops. Three of the five rib sections also have horizontal pieces of conduit welded on. These straight pieces will support the airfoils that may or may not get made this year.

Earlier this week I gave a presentation about the turbine to the Society of Physics Students (SPS), an undergraduate student organization that primarily hosts weekly talks about physics. A number of them were very interested in working on the turbine and would like to take care of it next year.


Master welder at work


Delicious ribs

More Frame Work

Matt, Jordan and I assembled much of the remainder of the frame on Sunday. It takes quite a while to drill through steel, so we were only able to attach the two long diagonal trusses and the top bearing support. To make a 3/8" hole through 1/8" steel using a hand drill required about 6 different bits - starting with 1/8" and working up to the 3/8" bit.

I was hoping we would be able to create the turbine ribs, but it turns out that welding EMT conduit to black steel pipe is trickier than we thought. Dan from University Theater diagnosed the problem and will hopefully weld the ribs this week. Bob got some work done on the pulley wheels, so I am looking forward to putting them into place.

Also, the flywheel should be arriving soon; it's a 90 pounder salvaged from a John Deere tractor.


Drill-master Jordan.


Me drilling holes for the top bearing.


You can see the two diagonal trusses and the bearing mount up top.

Materials

Jordan and I picked up some 1/2" EMT conduit from the Home Depot and visited Bil at Aerotecture yesterday. Bil sold us 6 lightly used square-flange mounted ball bearings at a very nice discount. We weren't able to use the bender at Aerotecture, but Bil suggested that we try Chicago Metal Rolled Products to coil the conduit for us. Chicago Metal worked on Bil's earlier turbines, before he got his own bender. They also created the curves in the roof on the Ratner Center at the University of Chicago. If you ever need to get some metal rolled, go to the guys at Chicago Metal - they were the most pleasant people to deal with and were kind enough to do the work for free. Ziggy was going to do the coiling, but one of the five Stanleys ended up doing it instead. As you can see from the picture, the coils were perfectly rolled to a 1.5' inner diameter.



Other materials: Last week we picked up a 4' x 8' sheet of 0.093" Lexan from Piedmont Plastics who also gave us a discount. The Lexan will be used to fill the gaps between the ribs.

Nuts and bolts from McMaster should be arriving on Saturday morning, so hopefully we can start putting some things together over the weekend.

Flywheel and Alternator Placement

Bob drew up this CAD layout to figure out where the alternators, pulley wheels and the flywheel will be placed. The alternator in the top right corner will be directly connected to the turbine rotor by a pulley belt looped around the massive wheel Bil Becker supplied us with. The other alternator, at the far left, will be indirectly connected to the turbine rotor, and will rotate with the flywheel. This will be accomplished by using an intermediate shaft (located in between the turbine shaft and the right-side alternator) that will transmit power from the turbine rotor to the flywheel. The lower pulley wheel on this shaft will be mounted on a bicycle freewheel, which will allow the flywheel to continue rotating even after the turbine slows down. In order to compensate for the rotational velocity that is lost by placing a pulley belt between the flywheel and the freewheel-driven pulley wheel, an extra-large pulley wheel will be mounted on the same shaft as the flywheel. This XL pulley wheel will be machined from a solid 24" x 24" x 1" piece of polyethylene, an extremely dense and rigid plastic. This pulley wheel will be connected via pulley belt to the alternator on the left hand side.

Alternator Porn

I took one of the alternators apart to see what it looked like inside. When I opened it up it looked like the magnets might have been rubbing up against the inside of the coils. You can see that the outer edge of the magnets are worn down and the inside of the wire coils are scratched, but this might just have been from the machining of the parts. The shaft seems to rotate a little more freely now, but we might want to file down the edges a bit.


Closed.


Open.


On left: note the rectifier sitting inside the cover. On right: the magnet rotor sitting inside of the coil ring. You can see the three sets of coils that comprise the three-phase configuration.


Magnet rotor.


Coil ring.

3D Turbine Rotor

This is a picture I made using Google Sketchup. I can't figure out how to fill in the spaces between the ribs. These spaces will be closed with either Lexan or Poly-Fiber on the actual turbine.


I will try to make a model of the frame so you can see how the turbine fits inside, and a model of the flywheel and alternator too.

Maroon Article

Read about the New Initiatives Fund and the projects that received funding in this Maroon article.

Turbine Supports

David and I put together the upper and lower supports for the turbine helix today. The lower support is welded to the frame, but the top one will be bolted on. This will allow us, and future custodians of the turbine, to easily remove the helix for repairs or tinkering. I also hammered down the ends of the pipes so we can thru-bolt them to the frame with greater ease. Bob is definitely a superior pipe-flattener.

Two photographers from the Maroon took pictures of me and David for an upcoming article (coming out tomorrow?) on the projects being supported by the New Initiaves Fund.


The frame on its side, showing the lower support.


A good way to take out your aggression.


The upper support.


Getting there...

Over the Weekend

After two trips to the Resource Center on 135th street, we ended up with about 150 pounds of steel for just 10 cents a pound. We're using steel pipe that David suspects was used for farm equipment as our cross-braces, and some really beefy punched steel to build the structures that will support all of the internals (eg the turbine itself, the alternator(s) and the flywheel).

Bob demonstrated with ease, though not without some bruises and burns, how to flatten the steel pipe, which had a 1/4 inch wall (not an easy task for mere mortals like you and me).


Locked and loaded, part deux: beefy steel.

Aerotecture Visit

Bil Becker, the founder and president of Aerotecture, invited us up to his office to take a look at our designs and share some wisdom. He took us onto the roof, which is home to an array of solar panels and one of his elegant Aeroturbines. We were all impressed by the turbine; it began rotating at the slightest breeze, and was quieter than the wind itself. With scarcely any moving parts, it is simple yet rigorously engineered.

Bil was kind enough to donate a pulley wheel and two alternators, which we will be testing soon. Thank you Bil!

Watch a video I took of the Aeroturbine today and hear Bil explain how it works.



Rotors


Jordan, Bob and Bil


The Aeroturbine


Beautiful gifts

Welding the Frame

The turbine itself will be housed inside of a rectangular steel frame 10 feet tall and 4 feet on either side. This morning I cut down the steel angle that Dan at the Experimental Station gave us and the steel we bought a few days ago. David made quick work of the welding, putting it together in under 2 hours. It may look like an open-sided metal box to you, but it's the first element of the project that's been physically realized.


David welding the bottom square


A textbook weld


Welding the frame



Standing tall

Steel

Matt and I drove out to Romeoville today to pick up the steel we ordered from Chicago Tube & Iron. Apparently, it was pretty obvious to the guys that worked there that we had never been to a steel plant before, but they were still very helpful. Welding the frame commences Wednesday.


Bay number 3


"Never been to a steel plant before, huh?"

Locked and loaded

Details

What makes the wind turbine we designed unique lies in both the turbine’s design and operation. In terms of design, the turbine is built around a vertical axis, which means that it is capable of capturing the wind from any direction. This is in contrast to the traditional “windmill” style turbine, which is built around a horizontal axis, and can only capture energy from wind blowing in the direction perpendicular to the turbine blades. There are also no “blades” on our turbine. Instead, there is one “sail,” helical in shape and made out of durable, light-weight Poly-Fiber sheeting – the same material used to cover light airplanes.

We knew we had an effective design when it turned out our design ideas had already been incorporated into an existing turbine – the aeroturbine, produced by a Chicago based firm, Aerotecture.

The unique aspect of the turbine's operation lies in its ability to store energy after it has been captured. One of the biggest criticisms of wind turbines is the intermittency of the power they generate. That is, they only generate electricity when the wind is blowing, unless you can somehow manage to store the energy while it is being generated, and then switch to the stored energy supply when the wind has stopped blowing. We intend to do this by using a flywheel connected to the turbine via a freewheel. In this way, the turbine will transfer power to the flywheel when the wind is blowing. Should the wind die down, the flywheel can continue spinning, even as the turbine slows down.

However, energy storage is not the primary goal, as it is not essential to the success of the turbine. The electricity created by the turbine can simply be directed back into the grid, whether it is produced intermittently or smoothly.

Space + Equipment

Unfortunately, building a turbine is not the kind of thing you can do in a dorm room or even in your apartment. No, you need to weld, machine and drill, and none of the equipment required to do this is cheap or easy to come by. I met today with David at Midway Studios, who is graciously allowing us to work there and will be helping us weld. Now we can finally move out the heap of parts I've accumulated in the hallway of my apartment.

David also directed me to the McMaster-Carr catalog for our bearings. I'm looking at model #5967K84, the Cast Iron Flange-Mounted Steel Ball Bearing 4-Bolt SQ-Flange, for 1" Shaft Dia, 3-3/4" Base. It's on page 1095.

However, I'm also considering the Nickel-plated version on page 1098 because it might stand up better to the outdoors. Even if you're not in the market for mounted ball bearings, the McMaster-Carr catalog is worth checking out. It's like flipping through a life-size lego catalog.

More details about the project will be posted over the weekend.