Hi, I am currently working on Auto yoke using 12VDC motor, along with force feeback. What I am doing now is trying to find any kind of information on driver circuits or a schematic that can show how I can wiring up/connecting toward to 12VDC stepper motor. I am looking for any components that can "invert" the motor into bipolar since DC motor can only go direct one way. I am trying to find any information that can input the ideas in order for me to build one. I spend two nights searching through google.com,yahoo.com and none of inquiries I am looking for has such details that explain the exactly information I am looking for. I also hope I could find any mechnaical link along with gears, steelwires, and etc. So can anyone help me guiding through that information on ineternet? If you have those information, care to share it out with me? I'd appreciate that.

Arthur,There is a new book that you may find especially useful. Building Robot Drive Trains by Dennis Clark and Michael Owings was just published last month. It addresses many if not all of the issues you raised. Amazon has it, but unfortunately does not list much detail of its contents. I skimmed thought it this morning at a local bookstore and it looked pretty interesting. It has an overview of motor types, offers basic circuit descriptions and discusses gearing.If you take a look on my web site you will find a list of sources for gears and other mechanical parts on the links page.The robot hobbyist crowd has a wide assortment of information on-line relating to this topic. You might try searching on "hobby robotics" on Google. It turns up a variety of potentially useful sites, like www.robotcafe.com which has tutorials that may be helpful.A suggestion: electric screwdrivers have a reversible DC motor and a gear reduction unit. If you can find them cheap, it may provide you with a good portion of the components you're hunting for.Mikewww.mikesflightdeck.com

Arthur, You may also do a seach with "CNC" as keyword. There are many people home-building CNC milling/engraving machines, which is basically motion control. http://www.stepperworld.com/ has a stepper tutorialhttp://www.luberth.com/plotter/plotter.htm DIY plotterhttp://majosoft.tripod.com/index.html some more info and linksHope this helps. Roland