Thursday, 26 December 2013

Elbow Mod Update

Since the last update I have fixed numerous bugs the navigation errors where due to a damaged encored disc and the arm jitter was due to mismatched names in the Joint state publisher. one of the requirement for ROS MoveIt is a follow joint action server this now works I was ready to start using MoveIt then the elbow worm broke again, the printer not working at this time so I incorporated the elbow mod into the robot.The original idea was to use a MXL belt but the weight and acceleration  cause the belt to slip, after a change to #25 chain and sprocket to operation was better. One side affect of this mod is the arm can droop down which on power on causes a sudden jerk as the arm moves to start position. A simple adjustment to the start position and to place the arm into the tuck position for driving will be required, maybe a spring to hold the weight   will also help.


  1. nice work,
    do you have a name or link for the motor/gear and the controller please ?

    many thanks

  2. Thank you
    The parts where what i had in the shed
    the motor is a 50 kgcm torque gear motor
    the controller is a arduino mini pro and a L298N motor driver controlled via I2C
    I will add the schematic on this link later

  3. hello,
    Where are you from ?
    I work in a famous french robotics labs.
    Can you give me your email to discuss about your work.
    thank you

  4. Hi
    I'm in Queensland Australia