16ft turbine part 2 repost from fieldlines June 22, 2009
Repost from June 22 2009 Hi Guys,
time for a progress report on the 16 foot turbine I am currently playing with. My last post on this machine can be found here
http://www.anotherpower.com/board/index.php/topic,99.0.html Magnets with a capital T
Well a lot has happened since the last posting. the metal work is now complete and ready to go on the tower, just waiting for the wind to stop blowing
The yaw tube was originally a hydraulic cylinder removed from an old JCB and the stub axle and flange are from the front axle on an old series Land Rover. I try to recycle as much as possible from my ever growing junk pile
The tail boom is 8ft long and follows the design from the Dans book for the 17 footer, the alternator is tilted back 5deg again all pretty standard stuff. I did however deviate from the design with the offset, I decided to go with a full 6% 11.5 inches. I pondered hard over the offset I studied many old posts on the subject I eventually decided that to much is better than to little and went with the full 6%. I may need to play with the tail angle/area to track the wind correctly and also with the weight to control the furling point. One other change to the design is a positive tail stop with a rubber bumper, this stop is made from 1.5 inch box section, it will also serve as a lifting point for hoisting up the tower but its main purpose is to prevent a blade strike when fully furled.
The trickiest bit to figure was the tail vane area as there are so many variables and conflicting examples so I decided to just guestimate it and tweak it later. I settled on a vane 6ft x 4ft of ½"ply
The stator is 3 phase 48v each coil has 40 turns of 2 in hand 1.6mm, I connected a set of bridge rectifiers and spun her up ,cut in at 48v was 109 rpm , right on target for a 16ft prop.
The tower this machine is going to sit on is currently flying a 12 footer it's the one behind the house
The 12ft machine is coming down and I will be fitting a new section that will give the tower an extra 10ft and anchor points for additional guys. The new section is 4" dia heavy wall galv tube it is 20ft long but 10ft will be inserted into the tower, the end of the tube is plated with ½" plate and it will have a ½" thick brass disc/washer as a bearing. I have also installed grease nipples on all the moving parts
The turbine at the front of the house is a 10 footer on a 35ft tower it and its tower are moving down the hill to run the lights and pumps for the Polly tunnel and garden features. I will then build a new 60ft free standing tower for the 12 ft machine it will be sited in place of the old 10 footer.... I think ...or at least that is the plan.
So that's the progress so far, all we need now is some decent weather!
Russell
repost from fieldlines June 22, 2009
