prop pitch motors (curtiss Wright 1944)

Discussion in 'General Technical Questions and Answers' started by VK2VKN, Sep 21, 2009.

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  1. VK2VKN

    VK2VKN QRZ Member

    Can anybody help with a circut diagram for the curtiss wright 1944 motor
    or any sugestions how to reduce the currant drawn. many thanks
  2. W6VPS

    W6VPS Ham Member QRZ Page

    Prop Pitch Motors

    Wow...I have talked to some old timers who used them as rotors.
    While I cannot help with your rquest these guys have a wealth of information on vintage aircraft. The CAF library / research department might be able to help.

    You might also try the Smithsonsian AIr and Space Msueum. I'm sure the museum restoration experts would know where to get such information.

    Good luck
  3. W4HAY

    W4HAY Subscriber QRZ Page

    It's a heavy-duty motor. Moving those prop blades requires some torque.

    If you can access the ARRL periodical archives, there's some circuits there. Typically, they show a 24V @10 Amp transformer and FW bridge rectifier. There is mention of quite a bit of RF noise when the motor is running, but bypassing the power connections using capacitors within the motor housing is offered as a solution.
  4. AB8XE

    AB8XE Ham Member QRZ Page

    If you want to reduce the current you generally reduce the load. Since most prop pitch motors have tons of torque, it would help to know what your turning with it, and of course, the model number, gearing changes, how you have adapted it, and so forth. My first guess would be that it is a 48v motor and your running it on 24v or 12v.
  5. KC0W

    KC0W Premium Subscriber QRZ Page

  6. K9STH

    K9STH Ham Member QRZ Page

    I used to have a prop pitch motor from a B-25, it could turn the whole tower. There were those who used a prop pitch motor from a B-29 and it could turn the whole house!

    The main problem that I had was to get the selsyn motors for the direction indicator working properly.

    Glen, K9STH
  7. KL7AJ

    KL7AJ Ham Member QRZ Page

    Hey Glen:

    I was always wondering about that. Did they have to run another whole five slip rings to get the selsyn data back, or were they able to somehow multiplex that on the motor drive slip rings?

  8. K9STH

    K9STH Ham Member QRZ Page

    The selsyns that I had used, if I remember correctly, 3 wires. However, that was over 40 years ago and I eventually went to CDE rotors.

    Glen, K9STH
  9. W0LPQ

    W0LPQ Ham Member QRZ Page

    The other issue is the synchros are 26VAC 400 cycle. Typical for aircraft use. Power for the rest was 28VDC ... not 12 or 14V. AGain, typical for aircraft use.

    The Handbook years ago had an article showing how to develop the 400 cycle power from two back to back transformers. Long since forgotten where they were.
  10. W2VW

    W2VW Ham Member QRZ Page

    Telrex used 400 cps selsyns on 60 cps by only energizing them while the rotor was turning. They worked OK. Takes 5 wires but no extra slip rings as the tower selsyn is stationary.

    Late 60s QST IIRC Windom wrote up a way around the 400 cycle selsyn problem. I have it here somewhere.

    I have a nice post WW2 prop pitch rotor controller here. It appears to use 24 VAC. The xfmr isn't too large. Maybe .3kva. IIRC the old (up to 1972 or so) Orr handbook A.K.A. West Coast Handbook has the diagram.

    I'm still not sure a B-29 used an electric prop pitch at at all.

    On 7/28/45 a B-25 engine and landing gear tore right through my current work space and landed on the roof of the building across 33rd st. If one knows where to look the repairs to the building are obvious.
    Last edited: Sep 21, 2009
  11. AI3V

    AI3V Ham Member QRZ Page

    Set of 1:1 gears.

    One around the mast, and one for the selsyn mounted next to the mast.

    Standard Navy RADAR used a second gear/selsyn connected in a 36:1/1:1 setup to give better angular resolution.

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