3 axis gimbal newbee questions

Discussion in '3 Axis Gimbal' started by Dave King, Dec 31, 2012.

  1. Dave King

    Dave King Well-Known Member

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    Please bare with me. I am just starting to fly my cinestar 8 with a 2 axis gimbal but I have been reading a lot and hearing a lot about 2 and 3 axis gimbals. When I was purchasing my cinestar Quadrocopter told me that if I was going to do all the controls myself to stick with the 2 axis and that a 3 axis gimbal would require a 2nd person. My question is why? On the MX20 there are 3 pots that could be used for pan-nick-roll. Isn't it just another pot you have to worry about? I know it would be easier with a 2nd person but couldn't 1 person do it if you had the copter in GPS and position hold?

    I will be doing jobs that will require 2 people but I was trying to figure out if I should build a 2nd cinestar for the 3 axis gimble and have the one I have for the one man operation of I can just convert my copter to a 3 axis gimble.

    thanks in advance for the help.

    Dave
     
  2. Tabb Firchau

    Tabb Firchau Administrator
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    Hi Dave,

    The main reason is when flying solo a 3 axis gimbal is A LOT to keep track of. It is usually less load on the pilot to just try and manage a 2-axis gimbal. You could certainly try but I personally find it overwhelming.

    Best,

    Tabb
     
  3. Andy Johnson-Laird

    Andy Johnson-Laird Administrator
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    Dave:
    To augment what Tabb said (he's absolutely correct), the heart of the problem is the pan axis. You need to keep situation awareness of where boom #1 is so that you can fly the bird correctly, safely, and resist the gravitation attraction of trees and buildings.

    But the pan axis of the bird is completely disjunct from the pan axis of the gimbal for the 3-axis gimbal. So you've now added the cognitive workload of trying to figure out which way the gimbal is pointing to the workload of figuring out which way boom #1 is pointed.

    Trying rubbing your stomach with your left hand, patting your head with your right hand, while reciting prime numbers below 500 in reverse order. You'll see what I mean. (Hint, the first one is 499.)

    Now that you've mastered that, add in the tilt axis management and stress yourself a little by realizing that you're probably less than 20 seconds away from a crash at any point in time -- less than that if you're distracted by trying to figure out where boom #1 is.

    You can mechanically convert the 3-Axis to 2-Axis by using Velcro straps to tie the gimbal booms to the motor booms and disconnecting the pan servo from the pan Radian.

    If you use a Spektrum satellite receiver to control the 3-Axis gimbal, and, say, a Graupner GR-16 (also mounted on the Gimbal), you can use the fact that the Radian's give the Spektrum signal priority, but will roll over to the GR-16 if there's no signal from the Spektrum (because the Spektrum transmitter is powered off).

    Andy.
     
  4. Dave King

    Dave King Well-Known Member

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    OK, thanks!
     

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