Optical Encoders + DC Motor to make mini-CNC ?

Forum 2005-2010 (read only) Hardware Interfacing
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G'day,

This is a 'before I start butchering more appliances' question :slight_smile:

I have recently done an epson flatbed-inkjet conversion, and have now a surplus optical encoder on the end of a shaft and a dc motor to drive it.

Its a 1440cpr encoder with a home mark.

Could I use this to make a mini-CNC (assuming I got some more encoders/motors..) ??

If I can do something like that - could someone point me in the direction of coupling a DC motor with an encoder in 'software' (I guess I could use a motor-shield to do this as well right and off load it from the arduino ?) .

Im getting very serious about putting together a real CNC, and would love to use some arduino's instead of just boring steppers and driver-boards :slight_smile:

It also doubles up for another project where I want to actually make the printhead move over the top of its printjob instead of using a feedtray - once again I'll need to convert the same encoder data to position information and drive my own DC motor (to pull the whole carriage at the correct speed).

Where do I start ?

Thanks everyone!

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Where do I start ?

http://www.arduino.cc/playground/Main/InterfacingWithHardware#Encoders

and would love to use some arduino's instead of just boring steppers and driver-boards

The RepRap project uses an arduino AND stepping motors to translate Gcode from the computer (or memory card) into motor movement.
The thing about a "real" CNC is that the designs depend on what you want to do with it. Milling wood is a different prospect from milling steel. One factor is the torque you can get from the motor and a stepping motor is the simplest way of getting good torque. With a DC motor and pulse feedback it is a bit more complex especially if you want good speed. You are then into servo control systems and the maths can get very heavy if you want to exactly define the "damping" of your machine.