Mechanisms and Things That Move

motion..control..?

April 10th, 2008

GuitarBot by Eric Singer

“Emergency Bot TV Theme”
by Joshua Fried
performed by GuitarBot
video

The Senster, by cybernetic sculptor Edward Ihnatowicz, is a large (15 feet long), hydraulic robot commissioned by electronics giant, Philips, in Eindhoven in 1970. It was the first work of robotic sculpture to be controlled by a digital computer.

video

I saw the video of GuitarBot and the video of The Senster around the same time. There is something compelling about the way the Senster moves. I started thinking about movement and how a machine can appear to be alive.

Linear Motion and Sensors:

-Slides

-Rails

-Linear carriages: bearing roller or ball carriages

-Linear Actuators

-Motors: DC, servo, steppers, solenoids

Instead:

-Acme lead screws

————————————————–Panama————————————————————-

Tried PIR motion sensor and realized it’s the wrong sensor for this.

I decide to make a mobile.

WIRE:

I made this puppet to look at balance, tension and motion. Connections are very loose.

Can I make a Geneva Stop out of wire?
MOTOR CONTROL

- Servo Motor as the linear motion for a piston to move the Geneva Stop: mess

Battery Powered:

- DC motor for linear motion for a pulley to move the Geneva Stop or direct motion of the mechanism: too fast and not enough torque.

- DC motor with gearbox: still too fast

USB Power:

- DC motor with H-Bridge:

L293 and SN754410

This didn’t work the first time I tried it. I was looking for an L293 for a couple of days thinking that it was the chip. It wasn’t.

I found a code for the SN754410 to control the direction and speed of a dc motor. In order to give the DC more torque, you have to attach a gearbox to it. I hacked a servo motor and turned it into a 360 degree gearmotor.

Servo Hack:

Open the servo. Remove all the gears. Pull out the potentiometer and remove it (cut or desolder) .