The original 17' turbine called for using 16" rotor plates, however they stated that the large magnets were pretty close to each other, so I am using 18" rotors. I am also using a 20" long piece of 5" schedule 40 pipe for the yaw bearing, primarily because my top stub for the tower will be made from 4-1/2" schedule 80 pipe and the 5" fits over it with extra a little extra room.

Other modifications included beefing up the entire spindle housing assembly, the stator brackets and the yaw bearing, in addition I had two 30" OD plates made up out of 1/4" steel that will be used to hold the blades on rather than use wood.

I started out by using a piece of 6" schedule 40 pipe for the spindle housing about 7" deep. Using two plates of 1/4" steel with 6-1/2" OD and a 2" hole cut into the center I welded the spindle shaft and housing together.

Rather than use round pipe to connect the spindle housing to the yaw bearing I decided to use some 4" x 6" x 1/4" rectangular tubing. It gives me more surface area to connect the two pieces as well as making it far easier to put the spindle housing on the 5 degree up-slant.

I also put the housing at a slightly greater angle as well, about 8 degrees rather than 5. I was concerned about blade flex and having them strike the tower stub so decided to increase this a bit.

Rather than using flat stock for the stator supports I used 1-1/2" x 1/4" thick angle iron, this will supply additional support for the stator. A couple of these supports were also welded to the yaw bearing where they had to be profiled to fit into their positions.

After about a day and a half I completed up most of the housing/yaw bearing without the tail support. Wherever possible I welded from both sides (if accessible) for even a stronger assembly. I am looking for some pipe/tubing that will fit better than what I have. But here is a bunch of pictures of the unit to date taken from various angles:

Here are more pictures of the assembly with the tail pivot:

Here are a couple of close ups of the tail pivot box section:

Next I moved my attention to fabricating the tail section. I cut a length of pipe that fit over the tail pivot and cut a section out so that it would pass over the boxed section. I approximated the rotation of the tail from 'normal' to 'completely furling', marked the tubing and cut out a section so that the tail could move it's full range of motion. I tried to get as close to optimal, and later on will probably need to 'tweak' this cut out section.

Then I used a 8-1/2' length of 1-1/2" pipe, cut it at 20 degrees and cut out a birds mouth so that it would fit over the pipe. I then had to use a jack stand on top of a small table to hold the pipe level so that I could weld it on. I then used some 2" wide 1/4" thick steel to reinforce the tail, in addition to two vertical braces and welded the entire thing up including a cap for the tail pipe. I will have to add some additional steel onto the tail so that I can mount the fin, but a pretty good start.

Finally I threw together a stand so that the entire assembly could be put together and moved easily.

Here are a bunch of pictures showing the tail on the assembly:

Unfortunately my chuck has a maximum capacity of 10" so I had to put the rotor on the knee mill, and using an adjustable boring bar opened up the inside hole to almost 5". Since I was on the mill I next put in six holes on a 6" bolt circle. Taking the plate over to the lathe I could now chuck it using the inside diameter and turned the outside diameter to about 11-3/4".

The brake rotor will be mounted behind the hub and held on by the 1/2" stainless steel threaded rod.

The brake caliper can be simply bolted on or it could be mounted so that it floats. I had a short piece of 4 x 4 x 3/16" square tubing and milled out a slot in one side so that the caliper would fit, I ended up using a die grinder to make it fit as good as possible while still allowing it to move freely. I had to cut away one portion under the caliper so that it would not hit the rotor.

Then trimmed the length and put on a back plate that will be used to mount it to the turbine housing. I could not put the brake caliper on the next vertical slot as when the tail furls it would have come too close to the brake mechanism, so I put it down into the next slot.

I modified the brake, the engagement rod was too short for my purposes so I used a longer piece of 1/2" round stock and modified it to fit the way the original shaft worked.

Finally I added a bracket on the back side to help hold the engagement rod in the proper position. Later when I know how I am going to engage the brake I will adjust the length.

Here are some pictures of the mounted brake caliper and rotor

I ended up taking off about 1/4" from each side of the corners, this gives me some extra 'wiggle room' in case I have to move the plates around a little bit so that the collars are in the proper alignment. Here is a shot showing one corner modification:

Just in case anything was off I decided to mark the orientation of both of the plates so that I could put them back into the original positions. I used a drill bit and made a divot at one corner of each plate as well as a couple on the matching side of the tower upright.

I had a piece of thick wall tubing with the dimensions 4-7/16" ID and 5-1/2" OD, about a 1/2" thick wall. This material I am going to use to make up two collars that will be welded into the center of the plates and the stub pipe of 4-1/2" schedule 80 pipe will go into.

I cut two pieces about 6" long each, and using my lathe bored the inside diameter to about .080" over the outside diameter of the 4-1/2" pipe. In addition to boring the ID, I put a rabbit on one end about 1/4" long so that it would fit into the hole in the 3/8" plate, this will help keep things aligned so that I can weld them into position.

Once the collars were made up I put them onto the stub pipe and put the pipe into position inside the tower. After wrestling around with the stub pipe (it's over 200lbs! and 14' long) I got it positioned correctly and tack welded the collars onto the 3/8" plate. Then I removed the stub pipe, removed the plates and welded them up, putting welds on the top and bottom side on of the plates over on my welding bench. Here is a picture of one of the mounting plates:

The plates are spaced apart by about 40" between them. Here are a couple of pictures showing both of the plates in position onto the top-most tower section:

The magnets that I purchased have a 3/16" hole in the middle of them. I planned on using this hole to 'pin' the magnets onto the rotor. Again this step might possibly be unnecessary, but doing it will allow me to use less resin around the magnets. There is almost no way that the magnets can now 'exit' the rotor despite just about any reasonable speed that the turbine might be able to turn at.

In addition it should make mounting the magnets easier as no placement template is required, nor any super-glue to temporarily hold them on until they are completed with the addition of resin. I have to believe that this is the ultimate in strength, and the more exposed area should help in circulating more air through the stator, and keeping everything cooler.

I started out by marking out the center locations of each of the 16 magnets on each of the rotors and drilled them out as a 'pair' By pairing the plates and drilling them out simultaneously I will ensure that the magnet locations match between the plates. I also marked an alignment mark on each of the rotors so that later they could be matched up

Each of the 3/16" holes were then drilled out.

Next I cut 32 lengths of 3/16" steel rod out just about 1-1/8" long. These pins were then inserted into the rotors, spaced so that they extend out the other side of the plate by just under 3/4" and then I TIG welded each pin into place, ensuring that they will not move.

So in all each coil used about 1.58 lbs of copper, and very little remained on the spools. To wire up the coils I ended up unwinding the last coil and cutting it, so each coil ended up being about 79 turns. So in all - almost 20 lbs of copper were used to make up the coils!

I found a couple of interesting points, one that winding the coils was a bit tougher than I thought, attention had to be paid to tension, winding evenly along with maintaining a rotation count. One other point was that once the coils were removed from the coil winder that they immediately expanded to about 1" thick!

Post Note: I wound the coils incorrectly! They should have been 59 turns of #14 wire - two in hand (two strands).

My approach has been a bit different than others in that I wanted to reduce as much as possible the amount of resin that went into a stator mold, in addition I wanted as much cooling around the coils as possible.

As much as I could look locally I could not find any 3/8" diameter bronze bolts, the largest I could find was 1/4". I wanted to put in the power studs into the stator when we cast it, but this will have to wait until afterwards.

Here is a picture of all of the coils sitting in the mold with some strips of fiberglass cloth super-glued to hold them together:

You can see the 1/4" thick plywood 'rose' which I cut out to basically match the outside of the coils (plus about 1/4"). All internal edges were filleted with some caulk to produce a radius - essential to help remove the finished stator from the mold.

The overall diameter is 22", and at each of the black lines will be a hole put in to hold the stator in place on the turbine. The mounting holes are fairly close to the coils, but have some clearance. I also made a side 'island' where the power connections will be made.

The central portion of the mold is 3/4" thick and around the outside edge I used some 1/4" plywood (on both top and bottom) to reduce the outside edge to about 1/4". Also I added blocks into the center of all of the coils that will 'open' up the centers to allow cooling air to circulate.

Each of the center coil blocks were lightly glued and then screwed from the back side to hold them in place. In addition I did the same for an 8" center island. My thoughts were that if the stator was difficult to remove from the mold then the center island could be removed and all of the coil center blocks could come out with the stator. Worst case is that I could remove the center islands from the extracted stator outside of the mold.

I wired up the coils in a 'star' fashion and brought the whole assembly over to my good friend Paul Schreiner, of PS Composites. Paul helped me out with finishing the mold, using some wax strips around all of the center islands, applying a coat of mold release and then a couple of coats of PVA which helps have the final product release from the mold.

Paul had just enough quantity of a special high-temperature epoxy that I wanted to use for the stator. I had seen enough references to burnt up stators to take this additional precaution. In addition milled fiberglass fibers and micro-ballons were used to thicken up the resin and give it more volume.

We then used a lot of strips of 10oz cloth cut into 2" wide strips and laid them into the voids, used about 3 quarts of the epoxy and clamped up the mold. All of the cloth was 'wetted' out and removed as many air bubbles as possible. Since we were compressing the whole assembly at least four layers of cloth were put around all surfaces as well as top and bottom of the mold, with even extra around the outside 'rose' area (probably up to 10 layers). This is a lot more than I have seen from others making up stators, but it should be an extremely strong and durable unit once done.

When we clamped up the mold we got some epoxy squeeze-out from about 90% of the edges so we are hoping that enough epoxy was inserted into the mold, if not it can be patched up afterwards.

The top of the mold consisted of one 3/4" thick plywood (with matching 1/4" plywood 'rose') as well as the 3/4" thick section of the mold that was removed when I routed out the main body of the mold

We used quite a few clamps to pull the top of the mold down onto the stator as well as a 1/2" bolt into the center, all of these were necessary to compress the 'expanded' coils back down to a reasonable thickness:

Next I had been wanting to build a couple of work platforms that will be near the top of the tower, this way when I am up there I am not standing on angled supports and killing my feet. I had found what I believe they call 'grip step', it is 7" deep and perfect for my application. I fabricated some angled mounts out of 1/4" steel, and they bolt onto the tower.

While at it I also welded in the two collars that keep the yaw bearing square on the stub, as well as a stop collar so that when I retract the stub it will have a positive stop.

Here is a picture of the top of the stub with the collars welded on:

Here is a picture of the completed crane, in all it extends about 60" above the supporting structure which should give me plenty of height to raise the turbine off the tower stub:

Here are some close up pictures of the pinned sections:

The picture above shows the bottom collar, which allows a 3/4" bar into it which will be used to keep the boom from retracting. In addition a long bar will be used to help rotate the boom so that anything being lowered can be swung safely away from the tower edge.

It was a good thing that I had planned for contingencies as it was necessary to remove the 8" center island, and all of the coil center blocks as well. It was not a pretty site as I ended up drilling holes in the bottom of the mold and using a 1/2" steel rod and hammer to remove them...

The culprit appeared to be that I did not build in enough of a relief angle around the mold center and all of the coil blocks. The wax and PVA that Paul put onto the mold worked fine and it would have released easily had I built it with some more effort and forethought, but time was working against me when I made the mold.

To make a long story short, I got out the stator in a single piece, however the mold was not as lucky. I have a bunch of cleanup to do around all of the edges but here is how it looks so far:

A gallon of the epoxy primer is the smallest quantity that they sell, but the urethane enamel they sold in quarts.

I had been looking around for some pulleys/sheaves for the crane winch cable and I just did not find what I wanted - so I decided to make a couple of them. I had some 2" x 3" aluminum stock that I put on the lathe and cut out two pulleys, I then used some steel tubing that was 5/8" OD and 3/8" ID and pressed fit them into the center of the pulleys. The outside diameter of the pulleys is about 2-1/2".

Finally I made up some cable brackets to keep the cable from coming off the pulleys and got them mounted in a suitable place. There is another pulley near the winch to help ease the transition from the winch to the top two pulleys that you can not see:

Post Note: The location of the hand winch is wrong, it forces you to have to reposition on the tower too much. I eventially removed the leftmost pulley and moved the hand winch to the top bar where this pulley used to be. The cable goes over the single pulley and down to the lift point at the bottom of the crane.

Finished up a bunch of small ends that I have been putting off, but now that I was preparing to painting the bare steel today finally got around to doing. Welded on some lifting U's for the main turbine housing and the tail section, as well as put on some supports for the tail vane, put hole into top of yaw bearing to pass cables through, and lots of grinding.

Did not get the color coat put on as I ran out of time, but I got all of the bare steel primered with about three coats of primer. In all I probably used about 1/2 gallon of primer to do everything, which once mixed with the catalyst equaled about 1 gallon total (it is mixed in a 1:1 ratio).

Got all of the steel painted today with the color coat of paint. I used a urethane enamel with the color close to a cobalt blue:


You have to be careful when spraying the urethane paints as they use a hardner that contains *cyanide*, yes that is what I said and if you are not careful about getting paint on you, someone else or even your animals breathing the overspray then trouble will happen! When I painted my Vortex I used a full body suit along with gloves and a respirator, since I was painting the turbine/tower parts outside I did not use the suit but I kept the dogs inside the house.

Due to the large amount of glue joints I will not be using a urethane glue (preferred) but instead I got a gallon of TightBond III wood workers glue. I used this glue when building my Vortex chassis and it is a very good glue.

My planer (a Dewalt) can only handle at most a 12" width so I did each blade into 2 sections. Each time I glued up a section I let it sit at least 2hrs in the clamps, then put in another section for glueing. After about a day I have the completed blanks for each of the three blades ready for the final diagonal cut on the trailing edge.

A lot of clamps were used to hold each section while glued up (about 12) and in addition I went through darn close to the entire gallon of TightBond III glue that I purchased (good call on the glue quantity).

In all after planeing, I easily ended up with at least 3 garbage can's full of chips. The nice thing about sassafras is at the mentholated smell coming from the wood is a pure pleasure to work with, I have heard that sassafras is the poor-man's walnut. I have worked with both and I have to say that my favorite all-around-wood is sassafras.

Finally after about a day and a half here are the three blade blanks that I will begin to shape into their final contours. Their length is 8-1/2' and width at the hub is about 9", total width is just under 14" wide just before the root, and after planeing they are about 2-1/4" thick. Their length is made from continuous pieces of wood, there is no splicing to make up the combined length, this is important as the OtherPower.com guys made their 17' diameter blades and spliced the wood - all three blades self-destructed at the joints!

I am trying as much as possible to learn from the mistakes from others in my endeavor, here is a picture of the blade blanks so far:

Instead of taking down the blade thickness as the first step I decided to cut out the pitch angle on the blade faces. This job progressed pretty fast and quickly I learned the value of my power planer. It was the absolute best tool to help cut out all of the excess wood on the face of the blade. I was able to fairly quickly bring down the surface very close to the line drawn for the upper trailing edge. Using the power belt sander to bring the final surface and to carve out the tight area in the root of the blade.

Between these two tools I was able to carve the pitch angle on all three blades within about 4-5 hours. I used a couple of the 'wedges' that were cut off the blade blanks to help raise the blades to a more comfortable work height on my bench and it helped a lot.

Here are a couple of pictures showing the blade progress so far: