Catch that ball

This automatic ball launcher was originally designed for dog training. Drop in a tennis ball and yell “Fetch!”  The ball hits the switch, the motor pulls the arm, and off it goes. I made it of whatever I had lying around in the workshop and it’s driven by an old battery drill motor. After a spell of baseball practice use, it is now used by another happy dog & owner.


  1. Did you use a PLC to control the timing of the system? I am looking to make something similar for my dog! Thanks!

  2. Hi, no, a simple microswitch in the swing arm, pressed by the ball. As soon as the ball leaves the switch opens again, and the motor stops, ready for the next ball. I just used whatever I had lying around.

  3. I want make something like that to! Do you have any photo’s where i can see clearly how it works? That would help me a lot to start. Thx

    1. Hi Sammy,

      I made this a few years ago from things i had lying around. The motor is an old battery drill powered straight from a nine volt power supply. On the drill there is a five cm pulley that drives a belt. The belt goes round the big 30 cm wheel. On the big wheel a bolt with a ball bearing. The arm has a strip on the side. When the wheel turns, then the ball bearing pushes against the strip, and as it continues to turn it releases the arm. There is rubber band (baggage straps) that pull the arm back. In the and is a microswitch that powers the motor. When the ball is on the switch the motor turns, so as soon as the ball is launched the motor automatically stops.
      The current owners dog now drops the ball in it herself.

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