Goldilocks and the 3D Printer

Once upon a time…

Just kidding! We won’t go into the whole fairytale, but we do want to talk about the proper way to calibrate your 3D printer by adjusting the z-offset. This is one of the most important steps for ensuring that your prints come out right every time, and it’s not a hard process. The z-offset is the distance from the extruder nozzle to the build plate, and a matter of millimeters could make the difference from “not a good print” to “just right!”. So how do you check the z-offset?

Your 3D printer likely has a few default prints that came with it. Our JellyBOX 3D printer has a 30×30 Calibration print that we like to use. Start your print. You should know by the first or second layer whether the extruder is too high, too low, or just right. Stop the printer, check the print, adjust the z-offset, and start another print until your 3D printer is perfectly calibrated.

Too High!
When the extruder is too far away from the build plate, the filament will not adhere well enough to create a stable print. The print may be too brittle and easy to break. In the image below, you can see gaps between each line. The filament doesn’t touch or overlap. The example on the left is higher than the example on the right, but the extruder is too far away from the build plate in both examples. Lower the extruder nozzle (or raise the build plate, depending on your 3D printer model) via the z-offset setting, and try another print.

Too Low!
When the extruder is too close to the build plate, the filament will be too squished to create a proper print. The print may be too dense and hard to remove from the build plate. In the image below, you can see raised bumps where the extruder nozzle dragged through the melted filament. The layers overlap too much. The bottom of the first layer may also appear very squished from where it was pressed into the build plate. Raise the extruder nozzle (or lower the build plate, depending on your 3D printer model) via the z-offset setting, and try another print.

Just Right!
When the extruder is the exact right distance from the build plate, the filament layers touch and slightly overlap with no gaps. In the image below, you can see the smooth layers without raised bumps. We printed a white and red square to show what a perfect print looks like in various colors. There is no need for further z-offset adjustments, and you can start printing for real.

Once the z-offset is just right, it will usually stay that way. However, it’s always a good idea to keep an eye on your future prints. If something doesn’t look quite right or the quality isn’t quite what you were expecting, it could be the z-offset. Watch each layer closely as your printer places filament. Try other designs and other filaments to troubleshoot; then adjust the z-offset, if needed. Happy printing!

Rhia Stark
STEM Specialist
rstark@tlcdelivers.com