You'd be surprised at how tight the accuracy has to be. Too loose, no friction fit. Too tight, you run the risk of ruining you legos. :/ Sarita -----Original Message----- From: Zachery Shivers <zachery.shivers@xxxxxxxxx> To: hackpgh-discuss <hackpgh-discuss@xxxxxxxxxxxxx> Sent: Wed, Mar 21, 2012 4:27 pm Subject: [hackpgh-discuss] Re: universal construction kit Plus, is your makerbot accurate to the micron? :- ) Do Lego's really require micron resolution to snap together?!