In the last step of the “configuration wizard” Cura will guide you through some steps in order to calibrate the build plate. For printing it is very important that the first layer is nicely squished into the glass plate and sticks well to it. If the distance between the nozzle and build plate is too big, your print won’t stick properly to the glass plate. On the other hand, if the nozzle is too close to the build plate it can prevent the filament from extruding from the nozzle.
Before the bed leveling can be done, the Ultimaker Original+ will first do the "homing". This means that it will move the print head to the left back corner and the build plate will move up. After this, you can follow the steps below for leveling the build plate.
Use the up/down control buttons until the nozzle just touches the glass plate and check if the Z limit switch is triggered. If not, you may have to adjust the height of the Z limit switch.
The next step is to adjust the build plate screw in the front left corner of the build plate for setting the correct height (the nozzle should just be touching the build plate). Turning the build plate screw to the left means that the platform will get closer to the nozzle.
When finished with this corner press “Resume” and the print head will move to the next point. Repeat these steps for all points.
During the last step, the Ultimaker Original+ will print a square on the build plate in order to check if the build plate has been properly calibrated. For this step, make sure that filament has been loaded!
Tip: For accurate bed leveling it is advised to use a piece of paper. Slide the piece of paper between the nozzle and build plate at each point and make sure that you feel slight friction when moving the piece of paper.
When 3D printing, it’s very important that the first layer is nicely pressed onto the glass plate with flat lines of filament and no gaps in between. Check out the below images to see a successful first layer and two unsuccessful ones.