Mount the dial indicator only during the leveling routine. The indicator or an empty indicator mount will not clear the frame through the extruder's full range of motion. (No I didn't smack mine to find out :-)This part mounts a standard 1" dial indicator to the Ultimaker 2 extruder head to assist in leveling the build plate. I have also included a shaft extension to print if you do not have a long enough one for your indicator. All holes are printed slightly undersized so you can finish them with a drill bit to the proper size for a tight fit on the indicator and a snug but easy to remove fit on the extruder. Leave the mount on the indicator and just set it over the left front knurled post on the top of the extruder while running the leveling routine.