What do you mean? Just gave a gentle suggestion to find a DIY site. There are several. He will get much better advice in one of those because there will be many users of hardware and software similar to what he has.
In case you don't know it, the owner of this forum wants to keep it about professional CNC machines and uses. There is a statement about that in the fine print somewhere.
It wasn't just you. And it wasn't just Mike (Finegrain). It was a combination of the two and that thefridge is a new poster here. Together, forming a pretty stark intro. My suggestion is - welcome the guy first, then question, advise, whatever. PM does have the reputation for being hard on newbies. For being hard on everybody, for that matter. I've gotten used to it and appreciate the frank nature of the conversation, but not everybody does. First impression/first post is important.
My apologies to you if I appeared to come on too strong. I meant it in a casual way. I did like your followup, BTW. You supplied information.
litlerob1: A lot of us started out as Harry Hacksaw. I certainly did, and improved my skills. Looks like the thefridge has, too. He's willing to ask questions and eager to learn. All excellent traits, IMO. If the moderator(s) wanna police the forum, fine.
thefridge: You still here, man?
Wikipedia has a good article on rotary encoders.
Rotary encoder - Wikipedia . Briefly, it's a gizmo that senses the angular position of the shaft it's connected to. Another gizmo interprets the signal and displays the coordinate (in the case of DROs) or to a CNC control/servoamp that controls the servomotor driving that axis. Encoders can be used for other things, too, but these are the two primary uses in machine tools. So it's a measuring device that is part of a feedback loop. A linear encoder does the same thing, and has the advantage of sensing actual position, whereas a system with a rotary encoder has to compensate for backlash, shaft windup, bearing clearance, chain stretch/slack, coupling flexibility/clearance etc. Linear encoders must be as long as the axis travel, so they'd be much more expensive than a rotary for your project. So the rotary has some problems, but most folks use them because they're less expensive than linears.
Stepmotors, maybe what you have, don't use encoders. The control just sends the required number of pulses to the motor, assuming the correct number of revolutions. There's no feedback loop. Still used some for DIY projects because of low cost.
Neil
I'd rather read about chain drives.
