Forum:Motors

There are several methods to move the cartridge back and forth in an inkjet printer, and they all have virtues. This topic is where we can discuss which type of motor would be best for thee printer to use. Available options are: Personally, I would go with the DC motors as this method is well established and they allow for a cheap and simple system, but I would like to see a few ideas.
 * Steppers (Provide moderate feedback, lose steps whenever an obstacle is encountered)
 * DC Motors (Very common in desktop printers. Cheap, but have no feed back and therefore require encoders.)
 * Servos (As far as I know, this has never been done before, but they would allow rapid accurate positioning, and would be well suited for the limited motion back and forth across the page.)

I've seen the following. Never seen a servo, but experiments are fun.
 * Steppers (more common in scanners and high end printers)
 * Optical encoders with two possible configurations:
 * 1) Ribbon mounted along the length of the printer, with the phototransistor mounted on the printer block
 * 2) Wheel with a phototransistor mounted near the DC motor

Steppers require a little more dedicated IC to drive, I've been learning a little about these, and have even considered using 2xDC motors and optical encoders to drive an experimental CNC prototype. Happy for others to step in here.

The disadvantage of the ribbon that I have seen is that it is often exposed to a lot of the crap that may spray out, and I've come across plenty that required a clean, and is potentially liable to some wear and tear/damage, especially on a project which will involve hands and tools being shoved inside the unit to tweak and modify as you go along.

The wheel encoder is a little neater, it sits to one side of the printer, suggest the opposite side to the ink resevoir (I keep calling it that, but what I mean is the gunge tank) to stop it from getting dirty.

I've seen some higher end All-in-one units combine a stepper for the scanner and 2/3 DC motors and optical encoders for the printer. I'm not in a position to test which is more accurate, but the encodings on the ribbons and wheels are high resolution.