Project: Building a wind turbine

[DaJe]

So some of you may remember a bit ago when I said I had to build a wind turbine for my engineering class. Well, I started on it now. I actually already started some work on it, and didn't take pictures of everything because making a worklog for it wasn't my priority. But, I'll show youw hat I have anyway.


First I'll give a quick overview of the design I have. I have a foot long tube of cast acrlyic with a 3 inch inner diameter. I also have 3 inch acrlyic discs. Those discs will plug up the ends of the tubes. In the middle of the discs will go a bearing. Through that bearing will rest a foot long aluminium shaft. On the end of that shaft is the blade, which I secured with bondo. I just took a blade setup from a fan and used it. Now, I have some neodymium magnets which are arc shaped. 6 of those magnets will go together to form a hollow cylinder of magnets. I originally had other magnets which would take 4 to make a complete ring, but I'll explain that later. Alright, so using rubber gromits to fill in the space, I secure the cylinder of magnets around the shaft. Along the inside walls of the generator housing will be rows of copper coils. Some of these magnets have north on the outside, some have north on the inside, so they alternate. As the shaft spins, the magnets will rotate past the coils, while the alternating poles will cause a magneting flux, and pull the current through the coils, generating a usable electric current.



Hopefully that overview was good enough, now onto some pictures.





I'm going to use acrylic to create brakcets to secure the copper coils to. I have a sheet of acrylic on which I overlayed paper, and marked out the lines to cut six 1.5 inch wide strips.

Here's what I'll be using for the generator housing. It's a one foot long, 3 inch inner diameter, quarter of an inch thick tube of clear cast acrylic.

Now, the tube will be cut in half down the middle, to make it easy to work inside of. The two half will be screwed together (was originally thinking of a hinge and latch) and will be able to be disassembled. The acrylic discs at the ends will also be cut in half, and have holes in the middle of them for bearings. Here is one of the discs, already drilled and cut, with one of the bearings in it.

The shaft is a 1 foot long rod of aluminum, half an inch thick. I took the blades off of like a desk fan, and used bondo and super glue to make sure they'd be secure.

I'll have to hand wind all of the coils from spools of magnet wire.

Here are the magnets. As you can see, they are arc shaped and pieced together to form one long cylinder. These are basically the most powerful ones I could buy. They're very fragile though. I've broken so many magnets over the past week.

So tomorrow, I'll wake up early and start more work on this, getting as much of it done as I can. I'll be sure to take more pictures and keep you guys updated on this as I progress.

[jdbnsn]

Check you out, way to go man!

[Trace]

Very nice! I may have to make one to power my computer and make my parents happy they don't have to pay the bill.

It's always windy where I live...

[DaJe]

It would be ideal for me to have this done for Tuesday. I have all of my materials, I have all of my ideas, I already have some of it put together. So I'm going to stop working on it today and attempt to get all of it done tomorrow night. The reason is that I can't risk cutting this acrylic by hand. Not the big tube anyway. Tomorrow morning I'm going to go into my school and hope that there is someone working in the machine shop who will cut everything for me. I really need machine precision. If there's no one willing to do it for me, I'll have to just do it myself at home, and hope it comes out alright. Once I have the tube cut in half, and the acrylic sheet cut into strips to use as coil brackets, I'll have everything I need and will just need to assemble it all. So assuming I get everything cut, I should be able to finish it all tomorrow night. I'll work all night if I have to.



I did do some more today, but I'm just going to update on this for now. The problem with the magnets were that the gromets I was using created a gap between some of the magnets. I now fixed that and have new gromets as well. I increased the magnets from 3 sections to 4.

On each end of this magnet tube, I have a rubber gromet. It slightly overlaps the end of the tube as well to help secure the magnets. These gromets will secure the magnets tightly to the shaft.

I also decided to put one gromet in the middle of the magnet tube for extra stability, as you can see in the right half of the tube in this picture.

[tinker]

looking really sweet!
It's cool to see something different every once in a while.

[DaJe]

So tonight I started winding some copper coils. I only had enough wire to make 4 coils. If I had more time, I would buy some online and have as much as I need. But I don't so I'll have to stop by Radioshack and buy some. All Radioshack has in a package of 3 spools, all of different gauges. So I can only use one spool from each package. Each package is also like 5 or 6 dollars. So I'll need to spend like $50 to get enough wire. It'll be alright though. And hopefully I'll also be reimbursed for some of it.





I've wound 4 coils so far, each one had 100 winds to it. I need 20 more.

The coils are going to be slightly longer than the magnets, unless I rewind them to be smaller. But rather than that, I'm just going to add more rubber gromets and break the magnets down into 4 sections, spaced apart slightly.

Now ideally, the magnets and the coils would be the same length. But, only a little bit of the coils will be outside the length of the magnet. I figure the magnetic field will reach our far enough anyway. And the majority of the coils will be along the length of the magnets anyway. This also makes another part easier. With the magnets together like that, they'd have alternating poles lengthwise, making me have to change the direction of the coils for each section. Now with them spaced apart, and the poles lined up, they can all be wound the same way.


The only problem is that I have no idea how to properly wire up the coils. Hopefully I figure that out soon enough.

[Fuganater]

You need 24 coils?!?!?! Holy crap dude thats alot of work. Hopefully you get it done on time. And get reimbursed for the wire.

[DaJe]

Well, each magnet section needs its own coil circle, and I plan to make each circle out of 6 coils.

[mofo]

Each turn (one wrap of wire) equals more power that the fan generates. there is a limit where the back current would actually stop the rotor from turning but its unrealistically high I think.
So him using more coils equals more power. AHHHhahahaha ha! sry had to.

At some point can we get some sort of wiring schematic of what you plan to do?
Great idea.

[DaJe]

Yesterday I waited around in the machine shop for a bit for the technician to come around and cut the acrylic for me, but he never did. So today I had my class, and went into the shop with my professor, and the technician was there too. He helped me out and cut off some of my acrylic tube, but then had to go. So then me and my professor just cut up the rest. And as long as the professor was there, I was able to use the saw myself.

We were originally going to do some testing of the turbines today, but never got around to it. I said I needed my turbine finished by today, but that just wasn't feasible. So I just hoped someone else from my team would have the one he was working on finished so he could bring it in. See, someone on my engineering team was working on one, but I continued to work on this one, because I just wanted it to be as great as it could be. The professor spent most of the class helping the other two guys on my team get the other turbine working right while I worked on what I had.




I had the technician cut off 4 inches of the tube, because I ordered a piece that was longer than I needed. After that, we decided to use that scrap 4 inches to try out the cut. We made sort of a bracket from scrap metal as a way to keep the cut straight.

My professor decided to be the one to make the first cut.

And then on to the big piece, the part that really mattered. I was the one to cut this one. No mistakes could be made, and if they were then the fault would be on me. Note: I was not wearing safety glasses like I should have been. I completely forgot about them until I was done cutting it. I did put some on afterward when I cut some more stuff though. You should always wear protective safety equipment.

It came out pretty good. A nice straight even cut all along it.

And as you can see, the circles I cut earlier match up with the tube, meaning it can be pull apart and opened up.

And then the bearings will rest in the holes in the circles.

So I should have this thing done by next week. What I'm going to do tonight is order some magnet wire online. Now that I actually have time to do so, I can get plenty of what I need for a good price. ****ing Radioshack... Anyways, I'll keep you guys updated on this over the next week.