Animatronic 10

After the LEGO line-following robot, Gérémy was in the mood for a more ambitious project.  After seeing the movie 9, he had his mind set on making a 9 robot(puppet).  

To keep things simple we agreed to make a new robot 10 inspired by 9.  Right away Gérémy started making drawings of the robot's insides and (not shown) the remote to control it.

Note the 'erased' 9 under the 10.

In reality Gérémy wanted it to walk and do everything that 9 does in the movie.  Clearly, this project needed to be scoped down.  To get us started, I went through my stock of parts and found some good things. I recently dismantled a robot dog (Wow Wee RoboPet R/C) and got five good servos out of it. We didn't have enough servos (motors) for a fully mobile puppet but we settled on having a mobile head with one mobile arm.  The robot would initially be a sitting animatronic on which we could add mode functionality later.

Even though we wouldn't need it until the end, we went ahead a got a couple of yards of burlap... for inspiration.

1) Servo Brackets
The servos we wanted to use had no attachment points so we decided to build some brackets that would create and interface between 2 servos.  We sculpted the original bracket in Castilene, made a mold in RTV rubber and casted our first 2 brackets in high strength resin.

The bracket fits at the bottom of the servo and has an interface on the side to connect with the spinning pin of another servo.

2) Testing the Neck Servos
Since those servos are really geared DC motors, we are going to use the Adafruit motor shield to drive them back and forth and control their speed.  To test their speed range we are using a potentiometer to send the full range of speed inputs from 0 to 255 trying to find the minimum speed.

The tests showed that 25 was the minimum speed before the motors stopped turning.