Truing the printing bed
Warning - the Print bed is set to true at the factory and for most users should not need to be changed. Truing is considered and advanced adjustment and may require considerable attention to accurately set the print bed up for printing. It can take considerable time to complete the adjustment accurately.
Often the term level or leveling is used. This is inaccurate as it assumes all parts of the environment are level which is more often not the case. If the surface the printer is on is not level, leveling the bed will actually degrade performance. The goal is to to get the nozzle to be dimensionally in reference to the print bed. This means the distance from the nozzle to bed is close to the same distance at the middle, corners and all points are similar to the point that you are able to print evenly over the entire build envelope.
1.As shown in the following pictures, move the bed up to close to the nozzle. Use a feeler gauge to check the gap between the bed and the nozzle. We recommend using middle of the bed as reference position. There are total 13 sets of screws so total 13 points to measure (Older units contain 9 sets of screws). According the measurements, mark down each point should be adjusted higher, lower or kept in position.
2.Take adjusting the position to HIGHER as an example. Loose the M3 nut as shown. Turn it COUNTER-CLOCKWISE about 2 rounds. If the screw is turning with the nut, then remove the glass plate and use a 2.0mm hex wrench to hold the screw and then loose the nut. After loosing then nut, put the glass plate back.
3.Use a 2.5mm hex wrench, turn the nylon tip screw CLOCKWISE to raise the heat bed. Use a feeler gauge between the nozzle and the plate to check the gap in between. After the bed rises to desired height, lock the screw in the middle by tightening the M3 nut. After the middle screw is tighten, then turn the nylon tip screw to normal tightness about 20Kgf.cm.
4.If need adjusting the heat bed LOWER, perform the same procedure as adjusting it higher, the only difference is turning the nylon tip screw COUNTER-CLOCKWISE.
5.Perform the same procedure to each point according to previous measurements of bed level.
6.Re-do the measurement as step1 to check if all points are at the same height. If not, adjust it accordingly. If yes, check if all screws are tight.
7.When the heat bed is leveled, before proceeding to print, check Z axis home position. Press ‘Home’ on ‘Utility’ for Z axis and watch it homing closely. If the heat bed hits the nozzle and still keeps moving up, power off the printer or use your hand to touch the Z limit switch to stop the bed movement immediately. Loose the lock nut in the back of the Z limit switch screw to free the thumb screw to adjust the gap between the build plate and the nozzle. Adjust the gap to proper distance (around 0.2mm) and then you can start your prints.