G1: calculate F for Flow test benchmark print
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Hi guys,
I'm a little helpless on my way to create a benchmark system based on cnc kitchen's Extrusion System Benchmark Tool for fast Prints to get values to compensate afterwards via M592.
My Problem is, that i do not get an idea, how to calculate the Fn parameter to achieve a certain Flow while moving the print head.
Example:
When executing G1 E300 F1800 the volumetric flow equals 72,2 mm³/s
How do i have to set up the F when i want to extrude the same amount with the same flow of 72,2mm³/s while moving G1 X1 Y1 Z15?Thank you, Fabian
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@TheTurboGuy
G1 E300 F1800means you are extruding 300mm of filament at 1800mm/min (divided by 60 seconds is 30mm/s). The extruder move takes 300mm / 30mm/s = 10 seconds.To extrude the same volume, at the same speed, you can just add this to the G1 XYZ move, and that's how much it will extrude, and at that speed (the speed of the slowest axis, in this case the extruder), during the move, ie:
G1 X1 Y1 Z15 E300 F1800The cross section area of 1.75mm filament is pi * radius^2 = pi * (1.75/2)^2 = 2.4mm^2
This is also the volume of 1mm of filament: 2.4mm^2 * 1mm = 2.4mm^3
Each second it extrudes 2.4mm^3 * 30mm/s = 72.2mm/s^3If you want to calculate the feedrate for a given volumetric flow:
volumetric flow / volume per second = feedrate in seconds
eg
50mm/s^3 / 2.4mm^2 = 20.83mm/s. For feedrate/minute, 20.8mm/s * 60 = F1250Ian
