I am an electronics engineering student who recently started working on Arduino. As part of my efforts to wake up on time, I decided that I should make an automatic water spray alarm clock. I have all the raw material ready (Spray Bottle, Arduino Uno, MG995 servo, external power supply for servo). I also have the test code ready. The only thing I am having trouble is how my servo should pull the spray handle.

Here is the spray bottle: spray bottle

And here is my thought configuration of where servo would be and the interface location (red doodling): mechanism

For this interface, my options are:

  1. Nylon fishing line. It is small enough to go thru mounting holes of servo arm of servo, but not strong enough to pull the spray handle.
  2. Something that sticks to plastic servo arm as well as plastic spray handle, should it be a rod or a long piece of wood that can be put in place with screws? This is the part where I am stuck, as to what should I choose as the interface that sticks tightly to the servo arm and the spray handle and pushes spray handle when servo moves.
  • 1
    $\begingroup$ Welcome to Robotics Prasanjit Rath, but I'm afraid that Unbounded Design Questions are off-topic because there are many ways to solve any given design problem. We prefer practical, answerable questions based on actual problems that you face, so questions which ask for a list of approaches or a subjective recommendation on a method (for how to build something, how to accomplish something, what something is capable of, etc.) are off-topic. Please take a look at How to Ask & tour for more information on how stack exchange works. $\endgroup$
    – Chuck
    Apr 15, 2021 at 19:29
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    $\begingroup$ I might consider bypassing the trigger mechanism entirely and installing a peristaltic pump to do what you want, as I think you're probably not going to find a servo that you're happy with. Finding a suitable peristaltic pump might be difficult, too, though. Determine the pull force required and the distance you need to move and that should determine the work you need, and then however quickly you need the sprays to happen with the given work would give a ballpark required mechanical power. $\endgroup$
    – Chuck
    Apr 15, 2021 at 19:31
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    $\begingroup$ nylon line stretches ... use a wooden icecream stick $\endgroup$
    – jsotola
    Apr 15, 2021 at 20:03
  • $\begingroup$ buy a small water pump $\endgroup$
    – jsotola
    Apr 16, 2021 at 20:08


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