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.