Feedrate/Flowrate?


#1

When printing using Ocopi, I am confused about the Flowrate and Feedrate that it shows while printing. If I set both in a slicer say at 70% and 70%, when printing it shows both at 100%. Now my question is, does that 100% mean that it is printing at 70% or is it actually printing at 100% or does it mean that it is printing at 100% of the 70% in the code that the slicer made? Am I making any sense?


#2

What you set in OctoPrint is multiplicative to what you set in the slicer. So if you set the flow to 80% in the slicer, and 90% in octoprint, the effective flow is 72%.


#3

Thanks for that response. it was what I thought it should be but didn't know for sure. Now I know. :slight_smile:


#4

Now that you’ve read the simple answer, let me expand on it a little bit. It depends a little on the slicer, and how you use it.

For example in Cura, if you set the material flow in the sidebar, it is as I said above. However, if you use the TweakAtZ gcode postprocessing script to adjust the flow halfway through the print, that uses the same gcode as octoprint uses to adjust the flowrate. In that case if you use the slider in octoprint it actually replaces the tweak you made with TweakAtZ, and vice versa.


#5

Understood, I'm just tweaking the sidebar on Cura. In S3D I'm adjusting the numbers in the settings.


#6

OctoPrint relies on feedback from the printer for anything it has the ability to display in terms of speed settings. Very few firmwares actually send back anything once given a command (other than a simple "ok" to say it got the command). Since the printers mostly don't send back anything, OctoPrint has no way of knowing what the printer's current feed/flow multiplier is. The only place you'll reliably find out what the printer is currently set to is your printer's own LCD display since it's driven directly from the printer's firmware.

Some firmware will send back tidbits of info when given a command, but it may send it back after getting it, and before executing it, or it may send feedback back after execution, due to the fact that not all firmware does it, OctoPrint doesn't look for it since it's an unreliable as to whether it exists, or how the firmware implements it.

If you set the flow to 50%, then refresh your browser, OctoPrint's UI will reset it to say 100% but the printer will still be on 50%, again this is because OctoPrint has no way of knowing what the printer is set to and so those buttons are just a convenient way of entering a number, they are NOT any indication of what the current printer setting is.