This page breaks down into 3 parts. 1. Level Check and Adjust 2. Full leveling reset (optional)
For most users, level check and adjust instruction is enough to get great leveling. Please only do full leveling reset only when leveling checks fail at all corners or the prints are coming out very compressed (<9mm)
Leveling for Moai means the build plate exert sufficient pressure on the vat bottom layer such that the printed object can stick well on the plate surface leading to a successful result. Without good leveling, print will fail. The good news is that once you set the leveling correctly, you rarely need to go back and adjust again. To measure the pressure from build plate, we print 4 cylinders, one at each corner of the build plate and then measured the height. The higher the pressure, the shorter the cylinder would be as the object was compressed slightly when initial layers are printed.
The cylinder (pegs) length represents the amount of the pressure that is on the vat and the letterings identify the spots on the vat. The shorter the cylinder, the higher the pressure because the cylinder is being compressed more. Our goal for Moai is to have all 4 cylinders printed and their heights are between 10.6 - 10.8mm with PDMS vat and 10.5 - 10.9mm with FEP vat. We can accomplish by turning the 4 screws underneath the vat platform.
The GCode takes about 30 minutes to print. When the four cylinders are done. It should look like:
This is what each letter on cylinder represents their location on the build plate:
The length and the letter of the cylinder represents the build plate pressure of a particular spot. The higher the pressure, the shorter the cylinder.
The ideal plate pressure would lead to cylinders with 10.6 to 10.8mm height, with 10.7mm preferred height.
Now that you know what your heights for each of the corner are, you have 4 possible scenarios.
Let’s say they are 10.35, 10.31, 10.32, 10.39. This shows the plate is relatively parallel to the PDMS layer; only the height needs to be adjusted. In this case, you can add 0.35mm to each corner’s height by tightening the nuts (clockwise turn when looking up to the bottom of vat) by half turn (180 degrees). Each full of the nut represents 0.7mm change in cylinder's printed height.
If the setting is ok and there are is no damage to the vat, go ahead and adjust the corner that was printed calculating the difference in height between current height and target height.
For the failed corner, do a full turn of loosening the nut. Repeat the process.
The goal of this process is to get the vat to actively press against the build plate with equal pressure. The vat holder has springs that will push it up towards the build plate. You will be adjusting the nuts that raise and lower the vat to make sure there is no space and the build plate is pressing against the vat with optimal force. There are slight variations in build plates and vats, it is important to level before doing any prints with resin.
You might not need to re-level when you are changing vats. We have tested it at Peopoly HQ with switching out several different vats and we didn't need to re-level, so you might try to switch vats without leveling, but if you have problems, level it! You should still do the Leveling Check process shown below to fine tune your leveling, even if you change vats.
If you haven't seen Practical Printing's excellent video on how to level, I would tell you to go watch this first so you see what all the steps are!
Leveling is THE hardest part of SLA printing and THE most crucial part. Please take your time.
(OPTIONAL) If you want to turn the printer completely upside down so its easier to get to the underside of the vat, do that now. Just lift the printer and put it on its top cover. You cannot have resin in the printer of course, it will spill when you flip it upside down.
Z Reset Positionto 1880
Double Pressto return to Main Menu
Z Reset Positionis already 1880, set it to 1879, and then go back to 1880 and double press the knob and the Build plate will start to move.
Main Menuand enter
Z Reset Positionto 1877, click the knob to save the setting
Helpful videos: leveling - the entire process https://youtu.be/gHHqfrhKt7M?t=5m58s
leveling - nuts tightening https://youtu.be/gHHqfrhKt7M?t=8m49s