3D printing basics: Understanding steps per millimeter and using Prusa's calculator - YouTube
3D Printer - Extruder Calibration
Calibrating Filament Flow Rate To Improve 3D Print Quality - Make 'N' Print
GitHub - vvaske/Extruder-E-steps-FlowRate-Calculator: Extruder E-steps & FlowRate Calculator by VASKE is easy tool to correct the STEPS/MM of your 3D Printer especially in case if you doing upgrade from Bowden tube to