How to Calibrate for Bottom Exposure Time?

Have you ever wasted time when the first layers of your print started to detach from the build plate mid-print? This is because you have wrong bottom exposure time settings. Here is how to find the optimal parameter for your printer/resin.

Why is it important to get your bottom exposure time right?

Underexposure will lead to first layers detaching from build plate mid-print.

Underexposure and detaching first layers

So should we just jack up the exposure time? No! Because overexposure also have its negative effects:

• Shorter screen lifespan

• Shorter FEP lifespan

• Create elephant foot / extra cured edge

• Model hard to remove from build plate

How to find optimal exposure time

1) Download the bottom exposure calibration model designed by Dennys Wang here: https://drive.google.com/drive/folders/1yrdJG4VQ74cll-kP6v9mgAPGR1UlO6RB?usp=drive_link

2) Place the calibration model into the corners and center of your build plate and test print with various bottom layer exposure time.

3) Choose the minimum bottom exposure time where all calibration models stick perfectly on the build plate.

This article is based on the work of 3D resin printing YouTuber Dennys Wang, watch his original video here: https://www.youtube.com/watch?v=m4ZeLO5yyC0