Quote Originally Posted by razer1141 View Post
...I've noticed my prints aren't as tall as they should be, but the other dimensions are pretty close to correct.
Are they compressed or cut off? If compressed, what values are you using for DEFAULT_STEPS_PER_UNIT in configuration.h? Another thing to check would be to make sure the tubing shaft couplers on the Z motors aren't slipping.

Quote Originally Posted by sniffle View Post
btw printbus, takes between 3-5 min for my 12" bed to hit 110 degrees. using 12AWG wire and 1 layer of cardboard underneath
Quote Originally Posted by pichuete View Post
i bought a 12v "30a" power supply from amazon one of those "Cheap" Chinese LED Power supply . and it only lasted 1 print. after that i put my RC charger power supply which is a 350w 12v and the power outlets where melting after 2 hours of use .
FWIW, both of these posts suggest the heat bed on the 12-inch printer draws a LOT of current. More than just the linear increase expected due to the increase in heater area.