Nose cone

Discussion in 'General Questions' started by murray2paddles, Dec 8, 2010.

  1. murray2paddles

    murray2paddles WindyNation Engineer

    In spare time I would like to experiment with making a nose cone for my Windy 500 & 750
    Does anyone have info on how to do an easy / safe attachment to the hub ?
    If so, please share info, attach photos. or caveman drawings :lol:

    I will make a mold and lay them up out of fiberglass / carbon .
     
  2. timber

    timber WindyNation Engineer

    Hi Murray,

    Can you incorporate 3 or 5 (depending on # blades) pieces of plumber's tape (metal strap w/ holes) into the mold to attach to one or two existing blade attachment bolts per blade?

    Just a thought.

    Dave
     
  3. Minnesota

    Minnesota WindyNation Engineer

    Love the idea. I think it would really help the 500/750 look more cleaned up and it could be a good selling accessory. All the pro systems have them.

    I'm a pilot and I'd be tempted to use a small aricraft nosecone to make a mold from. I'll dig around to try to find one that could be a good candidate. You likely could borrow one and then return it as they are a bit pricey.

    Minnesota
     
  4. timber

    timber WindyNation Engineer

    Another attachment method would be to have structural support within the shape to solidly hold a hub nut.
    Some blue loctite 242 would allow later removal but insure that it would stay in place until such time.

    I think this would be the preferred method of attachment if there is enough thread left protruding on the hub thread after the blade is attached.

    Dave
     
  5. murray2paddles

    murray2paddles WindyNation Engineer

    Minnesota, sounds good, I will look at dropping one of my towers to measure the space on the hub face after blades are mounted. I have spare hubs I can use after that for fitting. Haven't decided to make a plaster mold or a fiberglass one. Want to end up using a female mold and should not have to vacuum bag, just do a wet lay up.


    Dave, when you mentioned the thread available after the blade is attached , can you clarify which threads !
    Would this be the attachment bolt that mounts the blade or thread that might be left on the turbine shaft and the hub would be a spin on to a nut built into the back section of the cone? If it is shaft thread, there is very little. I like to drill a hole through the shaft end to put a locking voter pin to ensure no vibrations can loosen the hub mount ( just for safety) but on the last 500 there was not enough thread available to do this.

    Larry, does either of your windmax have cones ? If so how do they attach ?

    murray.
     
  6. timber

    timber WindyNation Engineer

    Yes Murray, the turbine shaft thread was what I had imagined using. The one you have been putting a cotter pin through.
    Guess that option won't work at all.

    It may be helpful to look at the nose cone as two pieces.

    1) An attachment or base plate (~1/8" thick disk up to about 10" diameter) secured to the innermost blade attachment bolts per blade. (retro-fit longer inner bolt if needed)
    This plate would have a ~2" diameter hole in the middle of it to accommodate the turbine shaft nut.

    2) The cone has has a means of attachment to the base plate.
    Some 1/4-20 nuts embedded at 3 or 5 locations along the inner perimeter of the cone could be attachment points.

    With the Windynation blade hubs there is a void area between each blade attachment point.
    This void area between blade attachment points would allow holes to be drilled through the back side of the attachment plate noted above.
    Countersunk heads would give this a nice clean look that would not cause additional wind friction or turbulence.

    The most difficult part of this construction would be aligning the attachment nuts and embedding them in the mold ... but ...
    If you have a pre-drilled attachment plate with countersunk bolts and nuts placed in each hole, you could lay-up the cone so that the resin is thick enough along the perimeter of the cone to embed the nuts. The pre-drilled attachment plate would act as a good template to hold the nuts in place as the resin hardens.

    Or ... The cone could be made smaller with the existing hub (rotor) drilled and used in place of the backing plate.
    The hub, in essence, becomes the backing plate.
    A standard hex head or cap head (allen) bolt could be used in place of the counter sunk bolt.
    The rotor itself could be use as the template to hold the nuts as they are set in resin.

    Just thinking out loud Murray, hope it helps.

    Dave
     
  7. Minnesota

    Minnesota WindyNation Engineer

    Here is one way it has been done. Clean look in the end:
    See time 3:50+ : http://www.youtube.com/watch?v=bEakCMoF3HU

    Perhaps a set of brakets than can share a pair of blade fasteners on each blade. The cone would then attach to the bracket with a single fastener between each blade much like in the vid.

    Minnesota
     
  8. timber

    timber WindyNation Engineer

    http://www.greenergystar.com/products/w ... de_hub.htm

    Could attach some small blocks to the rotor and just drill holes around the perimeter to attach.
    Similar to the way the hub is attached to the hub in the link above.
    Looks relatively simple and easy to construct with finished look.
     
  9. Minnesota

    Minnesota WindyNation Engineer

    L-Bracket Concept:
    [​IMG]
     
  10. Minnesota

    Minnesota WindyNation Engineer

    Using the L-bracket approach (artist misconception!): (You must admit, this looks way better.)

    [​IMG]

    Frankly, in order to clean up the whole front end, the long forward shaft needs to be hidden within the cone, imo. The best "look" would have the blade plane/hub just ahead of the front plate of the PMA and the nose cone attached such that there would be perhaps no more than a 1/2-inch gap between it and the PMA faceplate.

    I think this could be done without having to mod the shaft though it might be best to cut the shaft length down and rip new threads exactly where they need to be.
     
  11. TomT

    TomT WindyNation Engineer

    I would not go too big. Would still need air flow around turbine for cooling.
     
  12. Minnesota

    Minnesota WindyNation Engineer

    Good point. No wider than the faceplate width. A cone like this would likely improve the cooling.
     
  13. murray2paddles

    murray2paddles WindyNation Engineer

    Ok, anyone know the measurements on the face plate ?
    Might have to ask Windy if it is the same for the 500 & 750 .

    Dropped my 750 tower today to measure width on the hub inside the blades, wish I had read this first, kind of lazy to take it down again tomorrow.

    Sounds like a game show host, so is this your final answer, not to have the cone exceed the circumference of the turbines front plate ?
    So how do other turbines survive who are fully enclosed and have a cone ?

    murray.
     
  14. leamywind1

    leamywind1 WindyNation Engineer

    [attachment=0:2oq8dal7]Wind max hybrid 001.jpg[/attachment:2oq8dal7]

    Windmax come with a nose cone. No disrespect to Windy Nation.lol
     

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  15. TomT

    TomT WindyNation Engineer

    Most of the ones I have seen . The cone is just as big as the turbine. Like the wind max. The others probably have a controller in them to stop this or they are under rated so they do not get that hot even in high winds.
     
  16. Minnesota

    Minnesota WindyNation Engineer

    The PMA was designed to cool itself using free convection (indoors) - thus the finned heatsink case. Since by definition it will only dissipate heat when it is generating a lot of power, then there is by definition an enormous amount of forced convention (it's windy as hell). I would not worry about the PMA ever overheating unless there is no wind and it is just baking in intense sun, but even then I am speculating a bit on what its limits are.
     
  17. murray2paddles

    murray2paddles WindyNation Engineer

    how critical is the cone shape on the leading edge. could this be used or would it have to be rounded to function properly and not create turbulent air ? the flat spot is 3 5/8 wide.

    [attachment=0:2qhb1u7u]nose cone.jpg[/attachment:2qhb1u7u]
     

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  18. TomT

    TomT WindyNation Engineer

    I would finish the point with a piece of foam and fiberglass the whole thing. Then sand,paint,Put on turbine.
     
  19. murray2paddles

    murray2paddles WindyNation Engineer

    I put the foam cap on but I think I will just paint the foam black and show off the stainless steel on the rest of it.
    I did finish it so that it could be used to make a female mold. Someday if I have time I will finish up a full carbon cone.

    This has been an extremely inexpensive cone to make. I picked up the bowl at a dollar store for $ 1.50, it is stainless steel.
    Epoxied a piece of high density foam on and shaped. The bowl already has a lip on it so it can be drilled in 3 places and use stainless # 6 pan head bolts through the hub arms. After it is up on your tower it will look like it was from the factory.

    You just have to get over the bowl part.. It does not cheapen it, you are just being smart and green

    [attachment=0:ihnmpm14]nose cone 2.jpg[/attachment:ihnmpm14]
     

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  20. timber

    timber WindyNation Engineer

    I like it Murray, when the tip is painted black I think it will look great.
    The fact that it's inexpensive and recycled is great too ... We want pictures of it in place, of course ... :)

    Dave
     

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