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eibbor
10-01-2008, 11:01 AM
Hi,
· I've been looking at some parts, and I'm not sure what will accomplish what I need.· I'm looking at making a·kind of printer head·device.· Should I use a continous servo or a standard one?· I want to be able to keep track of position (like the head of a printer) so I thought standard, but then I want to run it over some distance (a foot or so like a flat bed scanner track), so I thought continous.

I looked at BS1USB and was going to use it to control the servos.· I'm basically writting a Visual Basic app that will send information to the servo to control it.· Am I way off on this part?· Should I really be looking at some other piece means to move and track the head?· Thanks in advance.

Mike Green
10-01-2008, 11:25 AM
You probably don't really want either kind of servo. These are both R/C hobby servo motors and are not made for the kind of accuracy you probably want. You want either to use a stepper motor or make your own servo mechanism with a DC motor and some kind of position encoder. Take a look at the stepper motor controllers that Parallax sells (like the Little Step-U Motor Controller). They're pretty typical of what you might want. Pololu sells a motor controller with provisions for position feedback (www.pololu.com/catalog/product/392 (http://www.pololu.com/catalog/product/392)). You'd need a position encoder for it and I don't have any recommendations for that.

SRLM
10-01-2008, 02:52 PM
You might try hacking an old scanner bed. These are set up with stepper motors already mounted in place, with pinpoint accuracy. If you get two, you can have a two dimensional printing surface. Since scanners typically can scan a 14" document, this is more than enough room for what you want. Plus, you might be able to get the old scanners for free!