Why isn’t my printer printing correctly.

Its tough to determine the issue without a little more information. What filament are you using? At what temperature are you trying to print? Is the bed itself leveled ?(not warped , some ender 3s have this issue) What methods have you tried to level the bed?

3D printing is definitely not plug and play. The main factors of a successful print are:

1. Proper bed. Type of bed and adhesion “glue”. This might be a PEI bed, which means a proper cleaning and bed temperature for the material used. Or it might be painters tape or hair spray on a glass bed.
2. First layer height. This is a combination of slicer first layer height configuration and nozzle distance to bed after a Z homing, controlled by the Z endstop.
3. Temp of hotend. This depends on material used, speed of printing and size of print.
4. Speed of print. This is limited by the printer mechanics, and should be set based on:

## The quality of print desired = slower for fine detail

1. The size of the print = faster for large prints with less detail.
2. Layer height. Smaller for fine detail,
3. Nozzle diameter. Larger for large layer heights. Most prints can be accomplished with a 0.4mm nozzle. I also like 0.3mm especially for finer detail and smaller layer heights.
4. A level bed. This will cause a varying first layer as an immediate indication. It will also cause head crashes in extreme cases.

Bunching of filament at nozzle would indicate that the filament is not adhering to the bed. This is most likely caused by the nozzle distance to the bed being too large. When you home Z, place a piece of paper, about 0.1mm thick, under the nozzle. You should just feel the nozzle grabbing the paper as you try to pull it out. Otherwise, adjust your Z endstop till it is correct.

If the distance is correct, the layer height might be too small, but that is least likely.