Hexonx

I'm having the same problem. My application is a print speed test: Set Print Speed in print settings to 100mm/s Use the ChangeAtZ extension to scale print speed from 50% up to 100% every 40 layers in order to monitor print quality of each vertical segment The documentation for M220 describes it as the code to set feed rate percentage. In Cura, the tool tip for ChangeAtZ.Speed setting describes it as "New total speed (print and travel)". Both indicate they are percentage values. The question appears to be "percentage of what?": percentage of the original Print Speed, or percentage of current Print Speed.