Windmill almost complete!

I skipped school today... =D. I did however, get a lot more done than I would have at school! I modified the axle that I found in the printer to allow for a skateboard bearing to fit on, then attached the windmill blades on the end. I have to secure it onto the platform but that is just a matter of drilling some holes and stuff. Attaching the motor might be tricky ... I get to build a motor mount! woohoo

Rotating Tower: Solved

So I was talking with my dad about bearings and my tower issue with not being able to acquire pillow block bearings, etc. and he had the idea of using an old computer chair as the rotating part. The pillar is probably hollow which allows for the wires, the top can be adjusted to fit with the base of my current windmill easily enough, and the very bottom can be fastened to whatever tower or post is available. Sweet!

In other news, today I ripped open a printer and found three motors! One DC motor and two AC stepping motors. Ethan swiped the DC one, but I still have two AC motors which are both permanent magnet (I assume) and are fairly strong. One generates up to 15V with the electric drill, and the other generates 10V with the electric drill. I'm hoping to attach one or both of these to the windmill, though I'm not exactly sure how yet. It's probable that just the 15V will make it onto the scene, but it would be cool to have two motors up there!

Images

First picture is of the tower joint between two 4 by 4's
Second picture is of the VAWT windmill from the side
Third picture is the VAWT from the top, so the blade profile is visible
Fourth picture is the HAWT windmill the broke the wind chime
Fifth picture is the swivel for the VAWT windmill that doesn't work
Sixth picture is some electronics: In my hand is the rectifier, the coil on top is from the dish washer, the coil on the bottom is from the fan (identical to the one currently on the HAWT windmill), the wood disk in the middle has some NIB magnets from various hard drives glued to it, and the rest of the stuff isn't too important.

Tower Construction Etc.

Today I decided to give tower building a try. I had some old 4 by 4's lying around from the tennis court fence and thought a few of them would make a good tower. I screwed some boards around the joint to hold them together and so far I have a pretty long 4 by 4 sitting in the garage. The plan from here is to take a couple shortened 4 by 4's and create a joint for the tower to pivot up and down on. The two shortened ones will be cemented into the ground, and in between will be some sort of rod that the third long one (the one sitting in the garage) will pivot on. It will be something like a trebuchet where in one position it is vertical (after the trebuchet has been released and has gone limp) and the other position the highest point is on the ground (trebuchet loaded 'n' ready). This is hard to describe with words, there is an image of a similar one here, though it is made of metal instead of wood and the pivot is in the middle instead of to one side. Anyways hopefully something will be erected in my backyard in the near future...

In other news, the HAWT windmill that I had made was wedged in an apple tree today and spun so fast that it broke a nearby wind chime. I was amazed, since it couldn't even turn into the wind being wedged in an apple tree and all.

VAWT Construction

So Ethan came over yesterday and we made a VAWT. It pretty much is awesome and we polluted the stream. The only problem is it doesn't work because the bearings we have (wooden dowel through drilled holes) kind of suck. I need to acquire pillow block bearings somehow, that way I'll be able to have good bearings and balance it correctly (it is a tower and when the balance is off, all the pressure is applied directly to the bearings).

Also someone on a forum directed me towards stepper motors as a source for magnets. Apparently printers and vending machines have them... so if Richard has some old printers....

Construction Time Again

Good album! In other news, I've been constructing the turbine itself! The first one is a HAWT with three blades. They are each flat boards attached to the main shaft at an angle so that when the wind hits them they turn from drag. I have also cut out pieces for a 'lift turbine' which uses an airfoil to get the tip speed much faster than the airspeed. This one will take a bit more work since I have to shape them just right.

The prop is mounted directly to a fan motor for now, which is taped to a board. It's very wobbly and wouldn't last ten minutes in any sort of "weather." The board that it is taped to will hopefully swivel on something eventually, provided I get some sort of bearings on it. For now the tail is rather useless, but it does have one.

I've got plans floating around in the back of my head to create a VAWT too. Might be about time to dust off the table saw...

HAWT vs VAWT

HAWT - Horizontal-Axis Wind Turbine
VAWT - Vertical-Axis Wind Turbine

So here's the dilemma. A HAWT is way more efficient, but it generally requires elevation. VAWTs are much less efficient because half the time they are fighting the wind, but they have the ability to be down low to the ground. Since I'm renegade, I am going to opt with HAWT and build a tower somehow =D. Other groups seem to have opted for VAWT, at the beginning I didn't understand why, but I hadn't considered the height limit of 3m. With that limit, it's probably best to make a VAWT since the wind will be so irregular down low.

I've got two plans going simultaneously as a result: (both HAWT)

Plan A involves three thin flat boards of wood. The thin boards will be mounted on a circle of wood at an angle using triangular blocks of wood. This will make a drag windmill I assume, since the air hits the blades and makes them turn.

Plan B involves some online instructions here. I've scaled them down to 50% and then squashed that a bit to allow it to fit my scrap wood boards. So far I've got three blade cutouts, but no shaping has been done yet. I think I might have to go to my friend's house to use his band saw. These blades will be much better once finished, but they will take considerably more work to construct. The tips of these guys are going to be very thin, so I may end up coating them in fiberglass for strength even though epoxy is rather heavy.

I'm still unsure of the bearing setup. I will most likely end up using the armature from the fan that I stole from the dump. In this case, it might be smart to build a rotor the same exact size as the one that originally matched the fan motor. We'll see how the magnet collecting turns out... I may want to buy a bunch that are the same size to fit with the armature that I have.