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Feed rate calculation for 3D printing

Posted by jakijain 
Feed rate calculation for 3D printing
October 25, 2018 09:59AM
For print a 3d model I make my own toolpath for each slice layer by any coding and I want to get Feedrate. In cura engine open source software, it will automatically calculate Feedrate. Behind this calculation, what formula they used.
Re: Feed rate calculation for 3D printing
October 26, 2018 01:35AM
Cura isn't open source, but there are other slicers where you can study their source code. (eg. slic3r )

I guess it's a combination of trackwidth x layerheight, e-steps and acceleration/momentary speed. Then count in extrusion factors or mixing ratios and such...
Re: Feed rate calculation for 3D printing
October 30, 2018 06:38PM
I think feedrate is just a factor that increases or decreases the velocity of all axes including the extruder. Normally the factor is 1, and if you want to increase by 50% you use 1.5x velocity of all axes (up to the limits set by Vmax).
In addition to looking at slicer code, you can look at the marlin firmware source code, a feedrate control is implemented. I haven't looked myself but by observing what happens when the feedrate is adjusted it seems to me only the velocity is affected. Increasing acceration and/or jerk would put the printer in the danger zone of skipping steps.


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Kind regards
Imqqmi

NFAN CoreXY printer:
[reprap.org]
Re: Feed rate calculation for 3D printing
November 03, 2018 09:24AM
I think formula may be extrusion width multiply layer height multiply print speed.
Re: Feed rate calculation for 3D printing
November 03, 2018 10:23AM
Quote
Mermarinc
I think formula may be extrusion width multiply layer height multiply print speed.

According the this web site that is correct.

[www.printitindustries.com]

Calculated from maximum volumetric speed in mm3 per second
Printing at 76 mm/s, with extrusion width of 0.44 mm and a 0.28mm layers height, your volumetric speed would be 76 * 0.44 * 0.28 = 9.3632 mm3/s

Edited 1 time(s). Last edit at 11/03/2018 10:23AM by Roberts_Clif.


Electronics Technician / Computer Programmer
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