Hack of the Whenever I Get Around to It

January 23, 2007

Revamped Animatronic Hawk

Filed under: Uncategorized — Chris Merck @ 3:30 am

For the film Lady Hawk the special effects people built a very cool, radio controlled animatronic hawk. I had the good fortune of being asked to build a board to automate the old movie prop – to make it move as part of a display for a theater lobby.

Beneath the taxidermy the hawk contains a radio receiver and many servos which operate its 7 axises of motion: wings, tail, beak, body, and 3-axis head motion. My goal was to make the hawk put on little performances on a regular interval, such as taking off, begging for food, or talking. (Of course it doesn’t talk or take off, it just looks like it is trying to!) The easiest way to do this is with some kind of automatic electronic system…

I ultimately designed and built a microcontroller board to interface with the RC aircraft controllers it uses. Here is a video of the hawk functioning under automatic control (and a closeup of the head motion). Yes, its motions are rather mechanical looking, but that is mainly due to the difficulty of manipulating many axises of motion simultaneously.

Some photos of the Hawk

The controller board is based around a microcontroller (Microchip’s PIC16F627) which sends voltage signals to the radio controllers through resistor (summing) networks and op-amps. Here are some photos of that controller at various stages of development:

testing the op-amp circuit in a breadboard

PCB, fresh from the board house

board populated with components forming a
test rig using ZIF (zero insertion force) socket
to protect the PIC


the finished board

close-up of a resistor summing network

The most trying parts of this project were fiddling with the op-amps to enable control of each axis, and the Assembler programming for the PIC – it seems like each time I sit down to write some ASM, I have to think: “O.K., what the heck does btfss do again?”

Overall this project was one of the more enjoyable I have worked on, as non-technical people can also appreciate the result. I hope the hawk enjoys its new home!


1 Comment »

  1. If anyone has any idea where this hawk is i would love to rent it out for a film. Please contact me at merelyhumanstudios@gmail.com

    Comment by michael — August 17, 2012 @ 10:07 pm | Reply

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