Print PDF
Favorite
Email
Step 5Tail
The area of the tail vane and the length of the tail boom are both dependent on the diameter of the windmill. This ensures that furling takes place at the right wind speed. The tail boom should generally be about as long as the radius of the turbine (one blade length). In this case, it should be around 3.5 feet. In reality we made it quite a bit longer by mistake. It still seems to find the wind alright, but I think it will effect furling.
As for the area of the tail vane, it can be determined by a simple equation: D(squared) / 40 = Area of the Tail Vane (where D is the diameter in your unit of choice). This equation is given by Hugh Piggot who has many years of small wind turbine experience.
The shape of the tail vane really has very little effect on the mill as long as the area is correct, so feel free to get creative. I spent some time with an air grinder and cut out a neat looking tail, but it's not entirely necessary. What does matter is the angle at which the tail is mounted. It needs to be at about 45 degrees from directly behind the center post on the opposite side of the generator. In addition to that, it should be mounted at a 20 degree angle from perpendicular - the pictures I've included illustrate this nicely. This may need to be adjusted slightly depending on when you want to mill to furl and how heavy the tail vane is.
The tail is made of electrical tubing and brazed together. We put a lot of supporting pieces in the middle of it to strengthen it. The tail vane is made of stainless steel and it is riveted onto the tubing.
As for the area of the tail vane, it can be determined by a simple equation: D(squared) / 40 = Area of the Tail Vane (where D is the diameter in your unit of choice). This equation is given by Hugh Piggot who has many years of small wind turbine experience.
The shape of the tail vane really has very little effect on the mill as long as the area is correct, so feel free to get creative. I spent some time with an air grinder and cut out a neat looking tail, but it's not entirely necessary. What does matter is the angle at which the tail is mounted. It needs to be at about 45 degrees from directly behind the center post on the opposite side of the generator. In addition to that, it should be mounted at a 20 degree angle from perpendicular - the pictures I've included illustrate this nicely. This may need to be adjusted slightly depending on when you want to mill to furl and how heavy the tail vane is.
The tail is made of electrical tubing and brazed together. We put a lot of supporting pieces in the middle of it to strengthen it. The tail vane is made of stainless steel and it is riveted onto the tubing.
| « Previous Step | Download PDFView All Steps | Next Step » |
2
comments
|
Add Comment
|
1
Aug 18, 2009. 8:25 PM0087adam
says:
Is that a weedeater with a saw blade on it!? (in the background)
Reply
3
Aug 19, 2009. 11:29 AMbrokengun (author)
says:
Yeah basically. It's for clearing woody plants and stuff. We live in the woods.
Reply
 |
Add Comment
|
