Command G04 codes for dwell: which creates a pause in your code for a pre-determined time that can be useful for a variety of different applications. You may want to initiate a UV curing, include a pre-flow delay, or give a thermoplastic time to solidify before proceeding to print the next layer. In order to create a pause in your code, the command is as follows:

  • G04 P# (creates a pause for # milliseconds) OR
  • G04 S# (creates a pause for # seconds)

It is important to make sure that either the valve is closed or the extrusion rate is set to 0 before the pause is initiated. This ensures that there is no leakage of bioink during your print. The valve can be closed with M761 (PH1) or M763 (PH2). To reset the extrusion rate, the code is G92 E0. 

In a case where a pre-flow delay of 500 milliseconds would be added to a G-code, the command is as follows:

M760; open valve
G04 P500; dwell
G1 X# Y # F#

See the attached figure below for more info on the command:

Image result for G04 g code

Source for figure:

“G04 - Dwell.” G04 - Dwell | Tormach Inc. Providers of Personal Small CNC Machines, CNC Tooling, and Many More CNC Items., Tormach Inc, 2018,