A drawing for a link of my snake robot, based on Dowling's design, but using larger servos..
The basic structure uses sections of 2x2 inch aluminum angle (1/16" wall), mounting the servos using their internal mounting screws. A 4-40 flat head screw is mounted in dimple (i.e. smashed with a ball peen hammer over a plate with a hole) in the angle. A standard threaded standoff is screwed onto the screw to provide a larger diameter pivot for the other arm of the yoke.
The yokes are made with 1"x1/8" (or maybe 1"x1/16", if it is stiff enough) bar stock. (They are made of 1/16". The two "U" shaped brackets are epoxied together with a single 8-32 screw holding it together in the middle. The screw's not shown on the drawing (yet).)
There are 9 total links, for a total snake length of around 2 meters.
Link for Scott Edwards Electroncs (http://www.seetron.com/) who make a nifty little PIC based RS232 serial to servo pulse converter. $44 each, 8 servo outputs, 2400 or 9600 bps in. 3 of them are used on my snake robot. More details on the snake robot wiring page.
Wiring and early electrical tests for the snake robot
http://www.snakerobot.com/ - very slick (albeit expensive) robots
http://www.snakerobots.com/ - Gavin Miller's very cool snake robots
http://www.dd.chalmers.se/~f96mahe/evcomp.html Moving a Snake Robot using Genetic Programming - 5 servos, mouse hanging off the end used to evaluate fitness... Interesting
http://www.frc.ri.cmu.edu/~nivek/OTH/resume.html Kevin Dowling's resume.. His PhD thesis is a great introduction (he's a good writer) to building a snake robot and discusses many of the issues. I can't help feeling that his project is just started, though. He got the robot built, worked out some algorithms, but actually doesn't report on actually running the robot with any measurements (except some power measurements?). Perhaps time ran out?
http://www.mil.ufl.edu/publications/FCRAR99/eno.pdf - Jormungand, an Autonomous
Robotic Snake Charles W. Eno, Dr. A. Antonio Arroyo Machine Intelligence Laboratory
University of Florida Department of Electrical Engineering
good pictures and general design and construction info.
http://set.gmd.de/~worst/snake-collection_b.html GMD's Collection of Snake-like Robots
robot/snakerobot.htm - 29 October 2001 - back to robots - back to Jim's home page - Jim Lux (mail)