Simple design for my new WN 500 PMA

Discussion in 'Frame Construction' started by timber, Oct 26, 2010.

  1. timber

    timber WindyNation Engineer


    This is how I plan on mounting my new wind turbine.
    I already have the 21' x 2-1/2" tilt-up pole with 5/8" diameter shaft extension.
    The plan is to use two pieces of 1-1/2" x 1-1/2" x 3x16" angle mounted with two pillow block bearings as the main frame.
    These will be secured to the PMA using 3 large diameter hose clamps.
    A furling tail will mount to the 1-1/2" angle as shown using a 5/8" diameter bolt and a scrap clamp that I had in the junk pile.
    I'll use 1/2" conduit as the tail frame and make it as long as necessary to provide proper furling.
    A bit of trial and error and luck should get me there after a few trials.
    I planned on a tail approximately 24" tall x 12" , not sure of the material I'll use for the tail yet.

    Any thoughts, comments, disgust or disdain are welcome.
    I made a similar frame for my last, home-built motor conversion alternator and it worked quite well but the furling used a screen door hinge on that one which was not a very good system the way I had it. I'm hoping gravity will work better and be more uniform to have better control over high and gusting winds.

    Attached Files:

  2. TomT

    TomT WindyNation Engineer

    A lot simpler than mine .
    Also easy construction.
    Like to hear how it works out. :D
  3. dank

    dank WindyNation Engineer

    Looks good to me, needs a slip ring. Dank
  4. timber

    timber WindyNation Engineer

    I don't have a welder so I try to get creative in finding other ways to put things together.

    Don't think I'll use a slip ring, I had my previous turbine up for 3 years and it never got tangled or wrapped more than once around the pole and always unwrapped itself as the wind lulled.
    I'm sure some sites might need one.
    I tend to think that the less outdoor connections or contacts the better, especially here in the Pacific Northwest where moisture and oxidation run rampant.

    I appreciate your comments!
    I'll keep you posted on how this works out.
    (Now watch it wrap the cord into a bundle and yank all the wires out ... just to make a liar out of me ... :D )

  5. windyguru

    windyguru WindyNation Expert

    I like it. It is very simply and creative.

    I would love to see some pics. as the build progresses.
  6. timber

    timber WindyNation Engineer

    I may need a frame brace to help support the weight/ torsion of the tail assembly.
    Will add one if needed. Could also incorporate the motor, thru-bolts to better tie it all together, we'll see.
    I do want to keep it minimalistic and easy to construct ... basically just a turbine with a flying tail.
    Hopefully it will be effective and easy enough to build that others can use the design.
    I'll take pics as I go.

  7. timber

    timber WindyNation Engineer


    Slight revision, I moved the vertical pivot back behind the turbine.
    Received my new Wintura 500 with WindGrabber blades, 3 phase rectifier and 2 load dumps.
    It came well packaged and arrived in 5 business days.
    I was like a kid at Christmas opening it up.
    Couldn't find my camera or I'd have some pics for ya.

    Cut and drilled my angle and dry fit everything together, I believe it's going to work out just as planned.
    As noted above, I made a revision to the bearing locations to better balance the unit once I get the tail on.
    Still need to purchase my down wires then install my rectifier, dump load, charge controller and Watts-Up meter.
    I'll mount the turbine on my existing tower (21' tilt-up, 2-1/2" pipe) but plan on building a new tower at the opposite end of the lot.
    Soon we'll be charging with wind power again ... just in time for late fall windy weather.
    I'll try to find the camera so I can get some pics as I progress.


    Attached Files:

  8. timber

    timber WindyNation Engineer

    The other day I noticed that I have the yaw bearing on the wrong side :roll: and I wasn't happy with the direction of the furling mechanism pivot, tilt.
    I moved the steel angle to the opposite side and added a piece of flatbar to the top angle so the furling pivot is now tilting at a compound angle,
    about 45 degrees as viewed from the top but tilting away from the turbine as well.
    I also added stops to that the tail will trail about 10 degrees to keep the blades into the wind on one side and prevent the tail from being able to collide with the blades at the other extreme.

    I'm very pleased with the way this works now, very much like the Windynation tail and the way it should be.
    Need to mount my yaw bearings and figure a good cable support that holds the down wires a few inches away from the pole.
    I'm painting up the frame pieces now and will work on a tail fin in the next day or two.
    Still can't find my camera or I'd have some pictures for you. I'll get some shots later and post back here.
    It's been very helpful looking at various setups here at the forum and it's great reading finding how others are getting along with their wind turbines.

  9. windyguru

    windyguru WindyNation Expert

    Hi Timber,
    I still owe you those graphs.

    One thing to keep in the mind is the tilt angle of the the furling pivot bar. We have ours set at about 20 degrees.

    If you go ahead with 45 degrees, your design will require a higher wind speed to furl if everything was left the same. With 45 degrees, you have two fairly easy options to compensate for the steeper angle: (1) reduce the length of your tail boom/vane or (2) reduce the weight of the tail boom/vane. Both these options will make it easier for the tail to furl and compensate for the 45 degree angle. But remember, you need to keep the surface area of the directional tail large enough so that the wind turbine can easily track the wind. Everything is a balancing act but it is good to keep this stuff in mind so that you can reduce the time spent on getting everything "dialed in".

    Also, I remember you saying you got trees on your property. Do everything you can to try an get 20 feet above the tree line. Trees or any object that obstructs the wind, will REALLY hurt the power performance of a wind turbine. If you can get that high, your results should be very similar to Murray's.
  10. timber

    timber WindyNation Engineer

    Hi Windyguru,

    My apologies, I didn't explain the tail pivot very well.
    The 45 degrees is as viewed from above, as if looking down the axis of the yaw bearing and viewing a protractor laying flat on the ground.

    The tilt away from vertical is about 20 degrees as you suggest. I agree, too much of a tilt away from vertical would not allow the tail to furl well, especially since the tail length is ~40" (or about half the blade diameter) and will have some weight to it.

    In other words, the axis of the pivot is a compound angle. If the blades were to face the wind coming from the north, the axis of the tail pivot would tilt slightly off vertical and toward the southeast. (This is one of those times when a picture is definitely worth a thousand words.)

    Regarding tail fin area, I plan to make that area a Minimum of 1/16th the wind swept area of the blades. (Actually slightly larger.)
    Since the wind swept area of the 35" Windgrabbers is approximately 35 sq. ft. I plan on the tail area to be a minimum of approximately 2.1875 sq. ft or about 315 sq. inches. (I'll shoot for something in the neighborhood of 24" x 14" or 336 sq. in (2.33 sq. ft).

    Murray's results are spectacular! My expectations are no where even remotely close to those, due to my location (lot size) and proximity to trees. Our firs are over 150' tall so getting 30' above them presents a bit of a problem, I'm afraid I'll have to live with what ever I can obtain ... and I realize that will be minimal at best. I'm not discouraged, however, challenged perhaps but not disappointed.

    In all honesty, I get great satisfaction from researching, building, educating the public (since others see the wind turbine) and reaping the benefits of an Un-interruptible Power Supply for our laptops or even keeping the refrigerator going during the occasional power outage.

    No rush on the charts, however I will be very interested in seeing them when you get time.

  11. murray2paddles

    murray2paddles WindyNation Engineer

    Hey Timber
    When Windy is talking about trees and my results I will paste a note that was part of a conversation with another of our forum members. This note will include the new 500 that was tested.
    murray wrote:
    " I have two turbines that collect clean wind from all directions but one. At that direction my neighbor has a stand of large aspens.They are approx 200 ft away from my turbine but when the wind blows from that direction I watch my turbines struggling to find wind and when they do the turbine can easily swing from side to side showing it is being hit with turbulent wind.

    Bottom line is I know how much neighboring trees can affect my turbine.
    Good news for me is, I am helping that same neighbor build his own turbine this year and those trees are set to come down this winter. Heck I even get to use them for firewood. "

    I just wanted to take advantage of the conversation regarding the need for clear wind in order to have good turbine results.

    Timber if a person does not have clean direct wind for a turbine how would a vertical axis turbine work in that situation ( turbulent wind) ?
    Your thoughts if those type of blades would preform better in that situation ?

  12. timber

    timber WindyNation Engineer

    Hi Murray,

    A VAWT is a great thought and may well be the best way to harness the turbulent winds here.
    A good plan might be for me to get the Wintura 500 flying as a HAWT for now, over the winter I'll rebuild my "Induction Motor Conversion" (It needs a rebuild.) When it's back in shape, I'll make a prototype VAWT using the Conversion unit to get the bugs worked out. If I gain some good results I'll think about using the Wintura 500 in this capacity.

    With the deciduous trees at bay over the winter I can at least maintain my humble battery bank (2 - 6V 220Ah AGMs) and setup my load diversion controller which will, of course, work with various types of WT. My control system is

    I should check out the VAWT section of the forum to get some ideas.
    Don't know if you are familiar with some of Ed's work at but he makes some impressive turbines and has experimented with quite a few designs. I like his Lenz turbines in particular and they appear to give some nice results.

    The nice thing is that I now have a GREAT alternator to work with and would just need to fab the frame and blades for a VAWT.
    Thanks to the experimentation and working designs of others , I'm sure I can come up with something.

    Thanks for the inspiration and ideas, I've toyed with VAWT's in the past but nothing on a large scale ... I'm glad you refreshed the idea, it's worth some serious consideration!

  13. timber

    timber WindyNation Engineer

    Wish we could edit our posts here, I see I left an unfinished sentence above ... please just disregard it ... :roll:
  14. windyguru

    windyguru WindyNation Expert

    I understand the angle now. It should work just fine the way you described it.
  15. windyguru

    windyguru WindyNation Expert

    Hi Timber
    I can not seemed to find those graphs. I will keep looking as I will also need them in the future. If I do not find them, we can re-generate them.
  16. timber

    timber WindyNation Engineer

    Not a problem, my system is coming together but at a snail's pace.
    Down the road the data could prove useful for comparison but the new graphs and video(s) on your site have already been very helpful in gaining some perspective.

    Still haven't found my "lost" camera or I'd post a pic or two of how my "simple" frame and furling tail section are coming along.
    Maybe I can take a still shot with my web cam in the mean time.

    I'm a little concerned about using "screw type" hose-clamps with this design, I think I'll try to find something more substantial.
    Three of these worked fine for a few years with my induction motor conversion alternator but it does seem like a potential weak link.
    I'd like to stick with a banding type fastener here but just haven't found the right one yet.

    Thanks (and not to worry),

  17. timber

    timber WindyNation Engineer

    There are now a few pictures in the photo section of my furling tail setup.


    It's not complete as shown. I will reinforce my stops with braces (making a triangle) and need a spacer in the tail section frame so it also forms a stout triangle. I plan on making a tail fin from 1/4" plywood and giving it about three coats of spar varnish so I can keep the natural wood look.

    I think the compound angle of the tail pivot will work nicely now. It should keep the tail straight during normal wind conditions and during high winds should let the turbine furl and return to face the wind as conditions allow. It's difficult to see the angle in these pics but the tail tilts up fairly high when fully furled (raises about 20 degrees).


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