Let's Make Robots!

Piranha Tank

Chases Fish Tank and tries to eat him


Piranha Tank was developed expressly for the purpose of pursuing Fish Tank


Piranha Tank's chassis was custom printed by Chris the Carpenter based on Geir's Timing Belt Tank design. He had to make a few small changes to adapt the design to the size bearings we had on hand.


His mind is driven by the need to feed. And what Piranha Tank likes to eat is... Fish Tank!

More technically, his brain is an ATMEGA 328 Arduino compatible on the Hobbytronics Hobbyduino Mini. I added a DIY shield to provide a motor driver, power management, and I/O interfacing.


I love these NiZn rechargeable batteries. They kick butt for a rechargeable AA, putting out as much as 1.8V when fully charged.


Still in development, but he can drive around, avoid obstacles with his IR sensor and two front-mounted bump switches, swish his tail and wiggle as he "swims", and search for the brightest source of IR light.

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Wow! That is cool! What's next? A Shark tank? :)

Maybe by next Maker Faire. ; j

Very funny video XDD

Thanks. Youtube cut off the first 3 seconds, which was annoying. If you rewind to the beginning, you can just see a title screen "Fish Tank Meets...", which is followed by the "Piranha Tank" screen.

Next time I'll start with a longer header on the video.

Yeah! The best part is how the pirhana's tail wags faster the closer he gets to his prey!

The best part is that behavior was pretty much an accident of programming.

OMG neat bone gnashers .... i would provoke you into designing some crafty moving dentures

That'd be sick, but would probably interfere with the DIY IR sensors below his teeth.

How deliciously Evil looking!