Extruder max feedrate
Posted by Enlightx
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Extruder max feedrate July 13, 2013 12:41PM |
Registered: 12 years ago Posts: 329 |
Hi guys
I'm been thinking about max feedrate of extruder
From what I understand max feedrate is classed as the physical limit of the printer
From what I can work out the default on marlin fir extruder is 45?
So o me this means my extruder will not run quicker then 45mm/sec
So if I open printer face set to extruder 10mm at 90mm/sec it will just go at 45mm/sec
Am I correct?
I want to print o faster then 90mm/sec in slicer what should. Have as max feedrates?
I'm been thinking about max feedrate of extruder
From what I understand max feedrate is classed as the physical limit of the printer
From what I can work out the default on marlin fir extruder is 45?
So o me this means my extruder will not run quicker then 45mm/sec
So if I open printer face set to extruder 10mm at 90mm/sec it will just go at 45mm/sec
Am I correct?
I want to print o faster then 90mm/sec in slicer what should. Have as max feedrates?
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Re: Extruder max feedrate July 14, 2013 09:56AM |
Registered: 13 years ago Posts: 1,797 |
yes firmware limits are in place to prevent sanity errors that will destroy printer or cause feedstock to jam. you can change those limits in firmware, or use repetier host and change the eprom settings for firmware as long as eprom writes were enabled.
be sure to do some homework on extruder settings before changing them. also know that backpresure reduces flow rate of extruder. max flow rate is a lot lower when nozzle is 0.15mm above surface and has flow resistance than it is free flowing.
be sure to do some homework on extruder settings before changing them. also know that backpresure reduces flow rate of extruder. max flow rate is a lot lower when nozzle is 0.15mm above surface and has flow resistance than it is free flowing.
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Re: Extruder max feedrate July 14, 2013 10:24AM |
Registered: 12 years ago Posts: 329 |
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Re: Extruder max feedrate July 15, 2013 04:59AM |
Registered: 11 years ago Posts: 19 |
No--that 45mm / sec extruder maximum is set quite high for retraction (negative motion of the filament), presumably, which can be much higher than actual extrusion (positive motion of the filament), because there is little resistance during retraction.
The extrusion feed rate required varies with the line width, layer thickness, and linear speed of the head. The product of all three gives you your feed rate required in terms of volume of plastic per second. As a rule of thumb, 10mm^3 per second is a reasonable maximum feed rate for a typical printer but YMMV. At 0.200mm layer height and 0.5mm line width this results in 100mm/sec head speed (0.200mm x 0.5mm x 100mm/sec = 10mm^3 / sec). For 3mm filament the linear feed speed would be:
10mm^3 /sec / (pi * 1.5mm^2) = 1.4 mm/sec (filament feed rate), which is far less than your Marlin limit so you don't need to change anything in Marlin to use a print head head speed of 90mm/sec, but don't try to go much "fatter" than 0.5mm lines and 0.200 layers at first at that speed.
Edited 4 time(s). Last edit at 07/15/2013 05:16AM by calinb.
The extrusion feed rate required varies with the line width, layer thickness, and linear speed of the head. The product of all three gives you your feed rate required in terms of volume of plastic per second. As a rule of thumb, 10mm^3 per second is a reasonable maximum feed rate for a typical printer but YMMV. At 0.200mm layer height and 0.5mm line width this results in 100mm/sec head speed (0.200mm x 0.5mm x 100mm/sec = 10mm^3 / sec). For 3mm filament the linear feed speed would be:
10mm^3 /sec / (pi * 1.5mm^2) = 1.4 mm/sec (filament feed rate), which is far less than your Marlin limit so you don't need to change anything in Marlin to use a print head head speed of 90mm/sec, but don't try to go much "fatter" than 0.5mm lines and 0.200 layers at first at that speed.
Edited 4 time(s). Last edit at 07/15/2013 05:16AM by calinb.
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