The Mechanics of Robotics: Using Motors, Solenoids, and Other Devices in Kinetic and Robotic Art
A two session introduction to the wide world of motors and mechanical systems suitable for use
in kinetic and robotic artworks. We'll cover the basic motor and solenoid types, including AC,
simple DC, DC gearhead, stepper and hobby servo. We'll play with examples of each type of motor
and talk about which ones are suitable where. We'll look at some basic mechanical parts and
systems like shaft collars, slip rings, gears, belts, pulleys, etc. We'll also talk about
sourcing components, creative reuse of found materials, material selection, building for
durability, etc. This class will not go in depth on motor control or electronics but will
mostly focus on the electro-mechanical side of robotics.
As with any topic of this complexity, you're not going to learn all you need to know in this
workshop. Our goal is to get you familiar with some vocabulary, basic ideas, and techniques,
and hopefully give you confidence that you can figure and experiment your way through the
problems you will inevitably confront. When we're done the next step is to just dive in and
start cranking away. The best way to learn is by doing!
Required materials:
work clothes that you don't mind getting dirty, safety glasses
Recommended materials:
an old electro-mechanical device (printer, scanner, fax machine, blender, something that moves!)
for sacrifices, charged 12v batter (~5 amp hours - email if you have questions about what to get),
soldering iron, small hand tools (snips, screw drivers, etc.)
I will bring a variety of motors and whatnots to play with.
Syllabus
DAY ONE
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FUN STARTERS
-
SUPER QUICK OHM AND FRIENDS:
- voltage, current, resistance, Señor Ohm's Law, etc
http://music.columbia.edu/~douglas/classes/electronics_workshop/part1.html
voltage (V in volts): potential difference. Battery, power supply.
current (I in amps): amount of flow. Water analogy.
resistance (R in Ohms): resistance to flow.
power/watts: voltage * current (V * I). More complicated for AC.
V = IR
I = V/R
R = V/I
W = V * I
THIS IS SOMETHING YOU NEED TO GO HOME AND GET COMFORTABLE WITH!!!
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USING ELECRO-MEASURING TOOLS
- measure resistance/continuity - demo with motor
- measure voltage
- measure current -- don't blow your fuse!!!!!
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SWITCHES
- what's a switch?
- touch two pieces of metal together -- YOU'VE MADE A SWITCH!
- commercial switches: the many faces of the switch
- homemade switches: guaranteed to work 73% of the time! wire one up today!
- kinds of switches: poles and throws
- two, four, six, ate, who do we appreciate? SWITCHES!
- what do we use them for?
- power switches
- limit switches
- toggle switches
- the switch as a source of entropy
Lots of good info on types of switches:
http://en.wikipedia.org/wiki/Switch
-
POWER SUPPLIES/BATTERIES
- reading ratings
- voltage
- current: amps & amp hours
- watts
- selecting a power supply
- batteries v.
- wall warts v.
- regulated supplies
-
TYPES OF MOTORS (this will take the rest of the day)
DAY TWO
-
TYPES OF MOTORS (continued from yesterday, if needed)
-
CONNECTING THINGS TO MOTORS
- shaft collars/couplers + set screws
make your own: tap & drill set -- BUY ONE!
- cotter pins
- pressure/press fit
- glue? tape? NO!
-
SECRETS OF THE ANCIENTS: THE MANY CONVERSIONS OF ROTATIONAL ENERGY
- directo drive:
- sliprings (aka commutators):
- gears
Arthur Ganson, hero of hand-made gears:
- pulleys + belts
Jean Tinguely used lots of giant pulleys with giant belts
Some homemade wooden pulleys
- sprockets + chain
Jon Kessler likes sprockets and chain!
Abbey Dubin's giant tricycle:
Lewis & Ewart's decorated sprockets:
- crankshafts, cams, linkages, variations
- lots of great models demonstrating mechanisms:
http://kmoddl.library.cornell.edu/resources.php
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CREATIVE DESTRUCTION
- Take apart your thing. What have you got? Switches? Motors? Optical encoders? A useful
powersupply? Finger remover? Toxins? Let's find out!
-
Some of the stuff in my studio...
-
CREATIVE CONSTRUCTION: LET'S MAKE SOMETHING MOVE!
Resources
books on mechanisms/interfacing/shop skills
Physical Computing by O'Sullivan & Igoe
Robot Builder's Bonanza by McComb and Predko
507 Mechanical Movements by Henry T. Brown
Machine Shop Essentials by Frank M. Marlow
Mechanisms and Mechanical Devices Sourcebook (3rd Edition)
by Sclater, N., Chironis, N.P. (free PDF text!)
Welding Essentials by William L. Galvery
The Woodworkers Visual Handbook by Jon Arno
The Artist's Complete Health and Safety Guide by Monona Rossol
websites for spending $$$
Herbach and Rademan: surplus motors, mechanical components,
power supplies
All Electronics: surplus electronics, small motors,
batteries
McMaster-Carr: new mechanical components, tools
Lots more at the bottom of this page:
http://projects.dorkbot.org/dorkbot-wiki/SourcesSources