printer bed leveling

[David Kavanagh]

http://hackaday.com/2012/04/23/automated-bed-leveling-with-our-3d-printer/?utm_source=feedburner&utm_medium=feed&utm_campaign=Feed%3A+hackaday%2FLgoM+%28Hack+a+Day%29

"Anyone with a RepRap or other 3D printer knows how much of a pain
leveling the bed is. To get a good quality print, the bed – the
surface the printer prints on – must be exactingly level, and may the
engineering gods help you if your surface has the slightest bump in
it. [Atntias] is developing a solution to this problem: an auto
leveling platform that shouldn’t require any parts at all if you
already have a metal bed.

The idea is incredibly simple: Just ground your metal bed, and apply a
small voltage to the tip of your hot end. [Atntias]‘ code (available
on GitHub) probes the surface of the bed and shoots out a 3D mesh of
your current bed profile. This can be used as a GCode offset, so the
bottom of your print is always directly on the top of the bed.

Although the utility of leveling a bed down to the micron level is of
questionable utility for 3D printers, it’s vitally important if you
want to mill a PCB on your printer. [Atntias] says his idea is
currently being implemented into the Marlin firmware, so it looks like
another firmware update is in our future.

Thanks go to [technodream] for sending this one in. Check out the
video after the break to see the bed leveling process in action."