This page has little tidbits of information about robotics, electronics, and other random subjects.
This section provides some names and numbers that you might be able to buy parts from. These are all companies that I have had dealings with in the past, and have a certain amount of confidence in their reliability. This certainly isn't a complete list, as there are many great places to buy new and surplus parts. Shopping for parts always seems to be half the fun.
Servos are available from most hobby shops, however the pricing between stores can change dramatically. Many people order their servos from Tower Hobbies, which is a large R/C model supplier. Expect to pay around $15 for a Futaba S-148 servo with all of the control horns. Tower sells other useful parts as well, such as wheels, cables, and motors. Getting their catalog is normally worthwhile, although they are notorious for sending you a catalog every other week!
Tower Hobbies, http://www.towerhobbies.com/
There are three basic ways of buy electronics that most people use: new, surplus, scavanged.
New supplies are always the nicest, since you often get exactly what you want. The downside is the premium price you pay. Many times, however, there is no other way to get certain parts. There are several mail order electronics suppliers. A couple that I have been quite happy with are:
Buying surplus parts, one can save an extreme amount of money. Surplus parts are quite often new (often called prime), high quality parts. The surplus dealers typically buy excess stock from various manufacturers which bought them to create their own goods. When a manufacturer changes or stops producing some design, they sell the excess parts to surplus dealers. You can quite often find parts for a 50-90% discount from the new cost. However, these are typically limited to stock on hand. Then availability becomes an issue. My suggestion is to try an buy parts surplus first, then new. Never hurts to shop around.
Some of my favorite surplus companies are listed below. All of them will send you a catalog if you call and ask for one. I suggest getting on all three mailing lists.
The last category of parts is scavanged, and one of my favorites. I have had good success finding old or broken consumer electronics and salvaging parts. Not only that, but after a while you will start to recognize how these machines are put together. A great learning experience. Here are some ideas:
There is something rather satisfying about taking apart some old gadget and finding useful things to do with its carcass. May I suggest, however, that if you only hang on to what you think you might need. Otherwise, you can easily fill your house with broken down equipment, and it becomes a pain to throw it away later. (Thats experience speaking!)
AK Peters Ltd is a publisher of books, many of which are excellent robotics resources. Their address is
Again, from AK Peters is Sensors for Mobile Robots. This is an interesting book. It shows many different types of sensors, has some background into the sensors design goals, and some algorithms. One thing it lacks, however, are practical implementations of these sensors. Don't expect to be able to build something out of this book.
*Dead Reckoning Sensors *Inertial Navigation *Tactile and Proximity Sensors *Triangulation Ranging *Time-of-Flight Ranging *Phase-Shift and FM Ranging *Interferometry *Range from Focus *Fundamentals of Sonar and Radar *Collision Avoidance Strategies *Guidepath Following Systems *Magnetic Compasses *Solid-State Mechanical and Optical Gyroscopes *RF Position Location Systems *Ultrsonic and Optical Position Location Systems *Wall, Doorway, and Ceiling Referencing *Security and Inventory Sensors
Another great book is the Robot Builders Bonanza. Though it was written in 1987, much of the information is timeless, and some of the chassis design ideas are also well done. Definitely one of the books to look into.
There are some really good books to help you learn about electronics. Check out your local bookstore. One book I have been pleased with is
This book seems to cover most of the basic topics of electronics, and then gives a good introduction to digital electronics. It is a pretty easy read, and one that you can learn from.
Another good source are books written by Forrest Mims III. He sells a series of reasonable books through Radio Shack, and most are reasonably priced. To be honest, I still end up referring to the same copy of his Engineers Notebook (bought new in 1981) even to this day. I would recommend the following book, or the latest in his series.
|Circuit Cellar||1-800-269-6301||This is a great electronics and microcontroller magazine. It focuses on real engineering projects using available techologies. They also have several sections on embedded PC design, and occasional robotic applications. A great source of information.|
|Nuts & Volts Magazine||1-800-783-4624||This magazine is an interesting mix of information and advertising. Much of the magazine looks like a classified ad section in the news paper with hundreds of little ads ranging from test equipment, ham radio gear, computer gear, etc. There is also a column written by Karl Lunt on Amatuer Robotics that usually has good information in it. Its also a great place to find ads for surplus parts.|
|Microcomputer Journal||1-719-254-4558||A good magazine about electronics and microcontroller based projects. The normal list of authors is quite impressive, and there are always a couple of projects to peak anyones interest, including robotics projects.|
There are many good web sites out there. I suggest trying one of the search engines to find topics of interest to you. Here are some of my favorites
Seattle Robotics Society
Portland Area Robotics Society (PARTS)
Robotics Internet Resource Page .
MIT Robotics Link .
Academic Robotics Web Servers
University of Washingtion Robotics and Controls .
Electronic solder comes with a core that is made of a substance called Flux. Flux is some nasty oily substance that helps solder flow correctly, and is extremely important to making a good solder connection. While I certainly can't explain the chemistry of how it works, I can tell you that it is very important to the soldering process. When you try to rework parts, however, you will find that the cooled solder joints do not have enough flux left in them. The result is usually a messy looking cold solder joint that probably is electrically weak.
For some relatively unknown reason, it appears that half the electronics guru's in the world have never heard of or used paste flux. However, go to just about any TV repair or electronic assembly house, and you will see a small can sitting next to every solder iron. You can order this from Digi-key as part KE1700-ND (costs $1.02).
Thanks for swingin by.