I'm probably missing something in the settings...I generate gcode in cura with a 60mms print speed, print with octoprint to an ender3...when the print starts there is a print speed multiplier applied....where did the multiplier come from? I did not add the multiplier. If I load the gcode again it has a multiplier added but it is different form the 1st multiplier. I don't understand where this multiplier is being generated. Marlin 2.0.7 2021/3/23, ender 3, skr mini e3, Microswiss dd. Any ideas?

If you mean the asterisk and number added at the end of each gcode line, that's not a speed multiplier - it's a checksum used for error correction. It's a necessary part of the protocol for communicating between a print host like OctoPrint and the printer. It does not affect the print speed at all.

No that's not what I mean, the speed multiplier listed in the marlin menu under tuning on the lcd when a print is running. It is not at 100%, I've seen it at 150% up to 300% but it's never the same even when I just re run the same gcode. This happens regardless of the slicer, both s3d and cura files have the same result. I have to turn the multiplier down to 100% to get what the slicer intended.

I've seen something like this before... but in that example the freed rate multiplier decreased

In that case they had a LCD with an buttons that used a single analogue input. Each button was represented with a different voltage.

The lcd was miss configured so when Marlin was displaying the status screen it was constantly receiving erroneous button presses that resulted in the feed rate decreasing.
(the number next to the ">>" icon on modern marlins or "FR" icon on older Marlins)

Spinning the knob when on the status screen will also change this value.

Edited 1 time(s). Last edit at 08/28/2021 02:45AM by Dust.

hmmm...I'm using a BTT TFT35 v3 touchscreen

M220 is the gcode that sets the feedrate percentage - for example "M220 S120" would set 120%.