[lotsofmangos]

The reprap ormerod is using an infra-red sensor for bed levelling, so no contact force. http://uk.rs-online.com/web/p/3d-printers/7952333/

There was a nice bed levelling project I saw on hackaday a couple of years ago that was cool as well, I think their method isn't covered by this patent either - http://hackaday.com/2012/04/23/automated-bed-leveling-with-o...

Also, the idea of bed leveling using contact force and other methods was discussed in the reprap forums at least as far back as January 2008 - http://forums.reprap.org/read.php?1,8028

[TaylorAlexander]

This is why patents like this are annoying. The idea of automated bed leveling wasn't novel by the time this patent had been filed, and doing it with force measurement is an obvious method to someone interested in automated bed leveling. There's nothing novel about doing bed leveling with force measurement.

[makomk]

Careful - Makerbot's parent company has a recent history of stretching 3D printing patents to sue over things that are obviously and fundamentally different from what was actually patented.