Bed Leveling Guide

Bed leveling is a crucial step for ensuring high-quality 3D prints. An uneven bed can lead to poor adhesion, incomplete layers, or failed prints altogether. Manual leveling is a common method used especially in 3D printers of old without automatic leveling features. Here’s some great information and tips to help you out if you are not familiar with the process.

Manual Level Paper Method

Manual Level - the Paper Method

First layer Squish for your Filament 
Setting your gap between nozzle and bed to get a very good first layer squish.
For PLA squish first layer to half height, for PETG do not squish first layer too much. Please see the example below.
For a more detailed explanation on first layer squish  please see this article written by Wham Bam.
Another great video on this is “How to get PERFECT First Layers on Your 3D Printer!! by 3D Musketeers.
Also, this video by The 3D Printing Zone.
Simplify 3D has an all around great article “Print Quality Troubleshooting Guide”.
What You'll Need
  • A piece of paper,  leveling card or a feeler gauge.
  • Wham Bam’s Bed Level G-code is a wonderful help
  • Cults3d.com also has a great document about Bed leveling written by Wham Bam
  • Tip: It's a good idea to preheat your 3D printer to the printing temperature because metals expand slightly when heated, and you want to level the bed under the conditions in which you will be printing.Also, the larger the bed the more time you should take for Pre-heating the bed. For Example a Neptune 4 Max should be around 25 minutes to evenly heat the surface as we have tested. 
Watch the Bed Level video here.

Auto Level

If your 3D printer is equipped with an auto-leveling feature, the process becomes more streamlined. Simply follow the same leveling procedure you would use for the default build plate, but with the new plate installed. To ensure accurate leveling, it's recommended to preheat the print bed for 5-10 minutes before starting the leveling process. This preheating time could be extended further, especially with larger plates, as mentioned about the Max earlier.
A little bit about Auto Leveling
In 3D printing, "auto level" refers to a feature that automatically calibrates the build platform (or bed) to ensure it is perfectly level with respect to the print head. This process simplifies preparation, as it is done automatically. Once the sensor maps the bed, the firmware calculates any deviations from the print surface and adjusts the nozzle height dynamically as it moves across the bed during printing. This adjustment compensates for any unevenness in the bed's surface. Sometimes, auto-leveling is combined with manual leveling, as seen in the Neptune 4 series with Klipper's mesh leveling technology. 
Alternatively MatterHackers has a great detailed article as well. Click here.