Tandem rotor gyroplane

Discussion in 'Rotorcraft' started by joe nelson, Jan 20, 2011.

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  1. Jun 17, 2015 #201

    joe nelson

    joe nelson

    joe nelson

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    Ken, It isn't full scale yet. It is about 40% scale and I choose this size because of the problems with the first models. I found the the rotor blades in the first models acted differently from a full scale gyro. It took me a year and a half to find this out. I found that the blade reflex on models needs to have a down reflex. I think it's due to the rigidity of the blade longitudinally. Small models have light weight balsa or basswood blades. When rotating it noses up in the relative wind and needs a down reflex at the trailing edge to compensate. I'm hoping that the 40% scale I can use a more rigid material in the blades to see if my hypothesis is correct.

    I certainly appreciate your kind offer to machine some of the parts and I may take you up on it. I'll need to cast more parts before committing to any help. I need to calculate the metal shrinkage for my parts which has come out smaller than the needed parts.
     
  2. Jun 17, 2015 #202

    Blue Chips

    Blue Chips

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    Ah, I had misread your post all on my own and should have not misinterpreted 4X as full scale after having read your post to date. Sometimes I amaze myself how the obvious can be overlooked.


    Offer to help in machining stands, if/when you may require that.

    Ken
     
  3. Dec 18, 2019 #203

    joe r nelson

    joe r nelson

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    Well folks, I'm still alive and trying to recover from my severe back injury which has kept me from doing much at all. I am sitting here reviewing my thoughts from over the last few years. I realize that I still love this tandem project and fully intend to keep it alive. In the next few days, I will be venturing down into my shop to inventory the project. I will update you all with the status of tandem.
     
  4. Dec 18, 2019 #204

    Turd Ferguson

    Turd Ferguson

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    You can't leave us hanging with that.......
     
  5. Dec 18, 2019 #205

    D Hillberg

    D Hillberg

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    Bad back too. Broke mine into retirement. Might limit what goes but it still goes...

    balsa is flexing with the lifting moment try adding a penny on the tip [get centrifical twisting moment to stop twist up]
     
  6. Dec 20, 2019 #206

    joe r nelson

    joe r nelson

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    sorry, I didn't mean to do or leave anyone hanging. The doctors had to correct an earlier fusion which didn't go well. I was unable to walk and it had nerve involvement which caused me to be incontinent. I am not accustom to wearing diapers or peeing in a jug. When I was able to use the laptop again the website had required me to reregister. Please understand no hanging was intended.
     
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  7. Dec 20, 2019 #207

    joe r nelson

    joe r nelson

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    Have you worked anymore on the Mac tandem?
     
  8. Dec 20, 2019 #208

    D Hillberg

    D Hillberg

    D Hillberg

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    Mac tandem????

    I do have a design laid out for an 8 place 'mini Chinook'.....

    Got 3 other projects going, 1/2 scale AH 1 cobra, Sky Shark, Coanda fan fin, medical deck for R44 or R66 helicopters
     
  9. Dec 20, 2019 #209

    Turd Ferguson

    Turd Ferguson

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    disc fusion of any kind is painful just talking about it. Can't imagine having to do it twice. Hopefully that is over and done with!
     
  10. Dec 21, 2019 #210

    deskpilot

    deskpilot

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    Good to see you back Joe. It's been a long time. I hope to see further work on the tandem gyro soon. In the meant time, I wish you and all other followers of this thread, a very happy and safe Christmas.
     
  11. Dec 21, 2019 #211

    joe r nelson

    joe r nelson

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    Doug, Things are moving slowly and I have to find my notes and brush off the dust. Today, I was looking at my main problem, as I remember it, the gear boxes. I've tried two types and both required many pounds of torque to turn them. This is a bad thing for gyros that depend on free wheeling to spin-up the rotors. If I can't reduce the gearbox torque, I will have to go to using partial power or a pre-rotator. All of this adds weight.

    Turd, I wished it end of the fusion thing but it is a on-going condition. The really bad thing is the medication needed just to function. At my age any change is difficult and takes a long time to overcome.

    I would also like to wish all a warm and wonderful holiday to all my fellow Rotor-heads and everyone on the website. God bless you all!
     
  12. Jan 9, 2020 #212

    joe r nelson

    joe r nelson

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    Today, I placed an order for three books on 3d printing. I like the idea of producing parts as I need them.

    If anyone has any thoughts let me know.
     

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