Minutes of the PARTS meeting on March 6th, 2004
Monty Goodson talked about dues and web hosting. Then he talked about having people that have not filled out the survey to do so we know what people want in the group. Next he mentioned that First contest is today and that this is the last day of the competition, there is a team from Newburg. They are teams from around the Northwest, including two teams from Portland, one from Wilsonville, and one from Newberg. This is the high school competition, involving large custom-built robots. Details here: http://www.usfirst.org/robotics/. First Robotics Competition March 5-6, 2004, Location: Memorial Coliseum, Ticket Prices: Admission to this event is free event: www.rosequarter.com. DARPA on the 16th of March and that one of the contestants rolled, article in Scientific American about the contestants. ROBOlympics at the web site www.robolympics.net is going to be held in San Fransisco on March 20-21st. Dan Gates mentioned that he is working on a deal for 30 people to stay in rooms for ROBOlympics. Steve, Tim, and Monty went down to Newburg to display their robots at a science fair. PDXBOT.04 update with who is doing what and about the Logo. Still need Organizer and Competition Coordinator. Monty then announced there would be two speakers for the meeting: Steve Davee on "Cheap and Kinda Easy -- Educational and Hobby Robotics on a Budget" and Chris Widener on basic physics of robotic drive trains.
Steve Davee related his experiences teaching second and third graders robotics, show off a few of the projects, and share some creative sources of supplies suitable for inexpensive, entry-level robotics. The materials for "Cheap and Kinda Easy -- Educational and Hobby Robotics on a Budget" came from Wacky Willies. He gets hobby motors, markers, cup, tape, and batteries for an art robot. He then had them adding a second motor for two axis and then can remotely control them using a controller that has two double pole double throw switches and a 4.5 volt C cell battery pack. He then got Teddy Ruxpin bears (Wacky Willies has tons of them!) that he dissected to get lots of parts. They provided a gearbox with the first stage, a pulley, then a group of different gears. He then taught the class to build a Mars rover out of 2 motors, wheels, and bear parts with the remote control to control the robot. He then worked with the students using the gearbox to build a remote controlled arm, and then put the arms on the Mars rover. To make the controller for the Mars rover and arm they put two of them together and connected the battery packs in series for the Mars rover and just one for the arm, to control both the arm and rover two controllers is needed. He also got CD parts that have 3 motors. Two linear motors and one rotary are in a CD drive. The motors are not steppers. He made a little Mars rover out of the CD drive parts, but the rubber bands fall off. A question was asked about adding sensors and the reply is to use bumper switches. Steve is offering to do this training for other kids.
Monty Goodson then showed, described, and demonstrated the PDXBOT walking robot contest. He then described and showed parts of the line-following contest, with Pete Skeggs showing is robot going on part of the line-following course.
Chris Widener spoke on the basic physics of robotic drive trains. That included about gear trains, tires where the rubber meets the road. He explained that a soft rubber tire surface is better than a solid. All surfaces are not smooth they are rough and you do not get complete contact. A soft rubber surface fills in the gap and makes more contact; also, the rubber will flatten and provide more surface area of contact. The robot with the best traction is the one that will win. Motor drive to the tires has friction and the gear train also has friction. With the more gears and axles the more friction the less torque goes to the wheels. Use the motor directly to the wheel and you get less friction and more torque. There is a consideration the size of the motor shaft to the wheel ratio for different speeds and torques. Without a transmission there is more room. With motor wheel drive for more room for other items like batteries and also can build smaller robots. With motor to wheel the motor wheel connection could deform the wheel rubber. Also if the motor connection slips on high torque a gear can be used instead on the motor and the wheel. The wheel gear can be on the inside of the wheel or beside it. There is a coefficient of friction for static friction when items are stopped and then dynamic where there is movement. Static friction is bigger than dynamic. Bigger wheels are an advantage because more area and coefficient of cohesion was mentioned.
Monty Goodson then talked about the sumo competition for PDXBOT.04 and the different size classes. He then demonstrated micro sumos. He then explained about the robot talent show competition and the technology demos.
Brad Lewis talked about his PICAxe project. He built a rice controller to control a hot plate to cook rice. He is also donating some PICAxe parts that use pBasic language to the library. PICAxe is at www.rev-ed.co.uk/picaxe/. He is also the librarian. The library is at www.library.bradlewis.com.
He also showed his project book that he uses for each of his projects for documentation.
Josh Triska told about and showed his $59.00 boards from PCBexpress at www.pcbexpress.com he used eagle software to layout the board at www.cadsoft.de.
Chris, did not get his last name, showed is Mark III robot.
Steve Davis showed a Scientific American magazine about the Mars Rover and the DARPA Grand Challenge.
Karl Boe is making a signal generator for some one. He then told about a polymer LCD screens that are LCD compatible dot matrix from www.crystalfontz.com. He also explained how he programs special characters on the display.
Larry Ossowski spoke about a robot book "Robot Programming: A Practical Guide to Behavior-Based Robotics" Book by Joseph L Jones, and Roth, Daniel get from Amazon.com that he found that the Seattle Robotic group at www.seattlerobotics.org reviewed the book.
Pete Skeggs showed gears from www.servolink.com that can be used for gears for the wheels as in the talk earlier by Chris Widener. They mesh with the brass pinion gears on the cheap Mabuchi hobby motors, enabling you to build a simple gear box.
Dan Gates from the southern robotics group showed Johnny that is a prop in the I-Robot movie at www.irobotmovie.com. The Mark III is LEGO compatable for connecting to LEGOs. The HC11 board that is compatible for the Mark III kit will drive the LEGO motors. The Mark III board needs the expansion package to drive the LEGO motors. He also showed a four-wheeler that he is working on. He has some Japanese magazines that had an article on the southern robotics www.sorobotics.org even RoboMaxx, in 6 weeks after PDXBOX.04. If we submit pictures then he can help PARTS create a calendar for next year. The calendars cost is $6 and then sell for $12 dollars for the group. He also showed his general-purpose chassis that he is working on for sale for $99 this is startup to pay for his robotic hobby at www.1sorc.com like at www.amigobot.com. He then showed SAM for servo-actuated-man that he is building. He built SAM with common tools so that anyone can build. He forgot to mention, but put in PARTS user group about graphical flowchart programming for the Mark III at www.1sorc.com and the other links here.
Jonathan Fant showed his robot Fred with sensors of infrared and ultra sonic that are controlled by an ARM board that communicates to them via I2C communications. He showed an Infrared communication modal for $55-60 dollars that will do RS232 serial and I2C Infrared communication from www.totalrobotics.com. He is looking for a cheap mechanical arm and would be a good business. He showed an O0Pic programming book that includes a picture of the Mark III robot called “Programming and Customizing the OOPic Microcontroller: The Official OOPic Handbook“ at Amazon.
Someone I did not catch the name told about Xscale version 200, or 400 MHz for $269 dollars.
Monty Goodson talked about next meeting guest speaker Edward Epp from Intel will talk about using Linux and the Intel X-Scale processor for robots: "I will demonstrate how to control an Amigobot through a web browser. I will focus on the Stargate board running Linux, Apache, Perl, and Player. The Stargate has a 400MHz PXA255 processor, 64 MBytes RAM, 32 MBytes of flash, Ethernet, USB, CF & PCMCAI slots, Bluetooth radio, and Mote connector. It is about the size of a deck of cards." For more information: Sourceforge site platformx.sourceforge.net/ Crossbow site www.xbow.com Data sheet pdf Amigobot www.amigobot Player playerstage.sourceforge.net About the presenter -------------------- Edward Epp has worked for Intel for 4 years and in Intel research for the last 1 1/2 years. During his time at Intel, Edward has worked on the Robotic Strategic Research Project and is currently working on in the Ubiquity Group that supports use of Intel's XScale(tm) platform in many technologies including the personal server, sensor networks and robots. Before joining Intel, Edward had extensive experience teaching students. He was a high school teacher and then taught at Goshen College for 4 years. Edward moved to the Pacific Northwest to teach Computer Science at the University of Portland for 10 years.
In May a group from OSU group to talk about Tekbot.
Monty Goodson talked about what he is doing to fix his robot mousetrap for RobOlympics and start on a nano-sumo robot.