Prusa bed level correction squares

thingiverse

This is a test print to set your printer's live z/z level/z offset and then correct the bed level if necessary. A light color filament will make this easier (white, yellow, or pink). First, print the single 25mm square to level you bed at the center location. You can do this with a caliper or by feel. If there are ridges then you need to increase the distance (live z towards 0). If there are gaps between lines or on the edges of the perimeterof the square, then you need to move the nozzle closer (more negative live z). Second, print the 5 square file and make sure that your center square is between 0.21mm to 0.23mm thick. The closer to .20mm the better. In any case the center square should have a smooth finish to it. Next, you want to start using the bed level correction feature. This is under calibration -> bed level correction. Negative numbers will decrease the distance between the nozzle and bed and positive numbers (towards 0) will increase the distance. If you measure the thickness of a square to be .18mm thick then you need to raise the nozzle or change the number more towards 0. If you have a number above .25mm then you need to lower the nozzle (more negative live z). The bed level correction is a very fine adjustment. Start with adjustments of 5 because this equates to .005mm. You can see a sample of what my bed level correction numbers were, but your numbers will vary. *Note this can be deceiving. Sometimes if the nozzle is too close it will cause material to pile up on either side of the nozzle path. This will create a "mountain" and actually make the square measure thicker. This is why a human factor is necessary. Once you get all of the squares the same thickness, adhering well to the bed, AND have good surface finish your first layer is calibrated.