3D Printing: How do the E commands in G-code work, exactly? The Question: I've tried looking online but haven't quite found the answer to what I'm confused about, exactly. Consider the following 3 lines of G-code: G1 X129.000 Y126.322 E7.90758 G1 X128.349 Y125.707 F7800.000 G1 X128.476 Y125.548 E7.92045 F1800.000 Does the absence of an E command in the second line mean that no material is to be extruded from line 1 to line 2? As I understand it, the E parameter controls how much material has been extruded up to that line. The reason why I am asking is because I'm trying to understand on the code level how to identify when a printer will travel without extruding any material, in the case of moving in the Z direction, or if you are printing multiple disconnected parts in one print. Since none of the Z lines seem to have any E commands, I'm inclined to believe that the absence of an E command means that when moving to the given position from the previous line, no material will be extruded. I've tried quite a few different queries online to try to discover if this is the case, but haven't found a simple answer, so I was hoping someone on this board could enlighten me. Solutions: Please watch the whole video to see all solutions, in order of how many people found them helpful With thanks & praise to God, and with thanks to the many people who have made this project possible! | Content (except music & images) licensed under cc by-sa 3.0 | Music: www.bensound.com/royalty-free-music | Images: stocksnap.io/license & others | With thanks to user yeemonic (askubuntu.com/users/4831), user Tom van der Zanden (askubuntu.com/users/26), user Greenonline (askubuntu.com/users/4762), and the Stack Exchange Network (3dprinting.stackexchange.com/questions/3028). Trademarks are property of their respective owners. Disclaimer: All information is provided "AS IS" without warranty of any kind. You are responsible for your own actions. Please contact me if anything is amiss at Roel D.OT VandePaar A.T gmail.com.