Hi All, Have been looking at buying a printer also.

Hi All,
Have been looking at buying a printer also. And also wondering - how do most of the printers do their positional detection? Is it using encoders? I had wondered whether laser based positioning was used anywhere (or even if thats even sensible)?

Endstops. Endstops set 0,0, and basically printers just remember how many step pulses they send the motor and where they should be. This is not a closed loop system. There is no positional feedback.

Thanks Anthony. Would runtime refinement be valuable? I know stepper motors should be accurate, but in experience with robotics in manufacturing this is rarely the case. Now I need to figure out what to buy.

Sure it would be valuable. But I think it adds unneeded cost and complication to an otherwise simple machine. This always seems to be the first place people go when they start out “I’m gonna be the guy who does positional feedback in desktop printing” yet it never comes to fruition. Whether that’s because of the difficulty of the project, or they get bored or decide its unneeded well never know.