Register To Comment
Page 2 of 3 FirstFirst 123 LastLast
Results 11 to 20 of 22

Thread: First build, be nice!

  1. #11

  2. #12

  3. #13

  4. #14

  5. #15

  6. #16
    I am not an experienced roboteer - but the following is based off my observations with Big Dave 3. I expect somebody else will have a better idea!

    That sounds like a (very) dodgy mix on the controller, or probably more a speed controller that's got different behaviour in forward/reverse. Big Dave 3's speed controllers do not have the same top speed in reverse as in forwards, and if one of your controllers is running backwards when the other is running forwards this could happen. I've seen this before when motors are mounted "upside down", the speed controller reversed to cater for it, and suddenly things don't behave how you'd expect.

    On Big Dave 3, we had to reverse a motor's polarity, as opposed to reversing the controller, because otherwise we ended up with this problem.

    The only other thing I guess I can thank of is that it could be that the speed controllers aren't centred in the same place.

    This is one of these things that without seeing/knowing all the control gear and its configuration I can't really comment much further. That said, you probably want to make sure your ESC pairs think they are going in the same direction with stick forwards. So undo any channel reversing (if you've applied any) and if you robot goes in circles at this point, you need to swap the wires on one of the motors with each other (since you're using standard DC motors).

    I hope that helps.

  7. #17

  8. #18
    APPENDIX AHow to setup Elevon Mixing for a Combat Robot
    Setting up channel mixing can be frustrating. You enable mixing and plug everything in only to discover that the robot is not responding correctly: it backs up when you command a turn and spins to the left when you try to go forward. Where do you go from there?
    This appendix describes a step-by-step process to get your differential steer robot responding correctly to a transmitter Elevon (Delta Wing) mix. This generic process places steering and throttle control on the right stick of a Mode 2 transmitter. For other stick assignments, consult the
    Team Run Amok Transmitter Programming Guide.

    1. Consult your radio manual and enable Elevon mixing on your transmitter. If your motor controller (ESC) has its own on-board mixing, disable it.
    2. If applicable for your radio, set both Aileron and Elevator response to 100%.
    3. Plug the left side motor controller into the channel 1 (Aileron) receiver port.
    4. Plug the right side motor controller into the channel 2 (Elevator) receiver port.

    Throttle Test: power up the robot and push the right stick forward a little (forward throttle command).

    • If the robot moves forward, good! Skip down to the Turning Test.
    • If the robot moves backward, select Servo Reversing from the transmitter setup and reverse both the Elevator and Aileron channels.
    • If the robot spins to the right, reverse only the Elevator channel.
    • If the robot spins to the left, reverse only the Aileron channel.Note: if your 'bot has multiple motors on each side of the 'bot and wheels on the same side of the robot are turning in opposite directions, reverse the motor leads to the ESC for any motor(s) spinning the wrong direction.

    Turning Test: move the right stick a little to the right (spin right command):

    • If the robot spins right, your basic setup is complete.
    • If the robot spins left, swap your motor controller plugs (left into Elevator, right into Aileron) and repeat the Throttle Test with ‘left’ and ‘right’ corrections reversed.

    Turning response will likely be too sensitive for combat. See the sections on Dual Rates, Throttle Volume, and Exponential Response in the main section of this guide to adjust control sensitivity.

  9. #19
    One wheel engaging before the other just sounds like your trims are out a little. Move the slider (or click button) below the stick on the aileron axle left or right in small increments until both motors/wheels turn at the same time. Bear in mind that some motors aren't neutrally timed too, so will spin faster in one direction than the other. Since motors are generally fitted back-to-back or opposite to each other, this can affect the straight line ability of your robot and can be cancelled out by sensitive adjustment on the transmitter stick when driving, but most of the time it's not severe enough to be a problem.

  10. #20

Register To Comment

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •