What’s a Nerf sentry gun without a sweeping rotation? I knew I needed motorized rotation to cover a wide field of (foam) fire, but how to mount the thing?

I disassembled the supplied tripod mount and found my answer: there was a spring loaded mount that clamped to the underside of the Nerf gun.


I went in search for a surplus DC gear motor that could be adapted to the mount clamp, and found a 250 RPM 12V motor with a plastic disc attached to its shaft. I marked and drilled some holes in the disc to screw the mount clamp into. Now I’m ready to build a stand to attach the motor to and bear the weight of the entire sentry gun. There’s no way the plastic toy tripod it came with is up to the task, so I’m checking out some t-slot aluminum instead.


In the Maker Shed:


Arduino Duemilanove

John Edgar Park

John Edgar Park

John Edgar Park likes to make things and tell people about it. He works at Disney Research and writes for Make and Boing Boing. He is training for American Ninja Warrior. You can find him at and twitter @johnedgarpark — if you like that sort of thing.

  • Nate

    Continuing awesomeness, John!

    The final touch will need a beeping as it sweeps, a la Half Life.

    • John Park

      Oh man, you’re right! I’m imposing a feature lock on myself for getting it finished for Maker Faire, but sound goes high on my list of things to add in real-time at the Faire, or afterward.

  • Theo Flokos

    Hi again, its very good but i think the motor its very big too ,how are you going to make the up-down rotation ?

  • Theo Flokos

    Can you tell me which motor did you use for the motorization system?

    • John Park

      I’m only doing pan (side-to-side) rotations, no tilt. I’m very impressed by the fully targeted systems, but I’m doing a much simpler system than that. I’ll see if I can find markings on the motor, but it was a random surplus 12V gearhead motor from All Electronics, so it may be impossible to track down an exact duplicate.