How to control extrusion rate in a 3D printer?

[PSB]

Suppose you are printing a layer with varying width. How can we manupulate the extrusion rate? I know that we can do it manually, but then it is lots of work. I would like to know if there is a a way that we can change the extrusion rate while printing a layer with varying width.

[alankilian]

@psb Every straight move says how much the extruder moves.

So, here is a square with one fat side:

M83 ; Use relative extrusion amounts
G1 X0 Y0 E0
G1 X10 Y0 E10
G1 X10 Y10 E10
G1 X0 Y10 E20
G1 X0 Y0 E10

So, as you print your layer, you can set the amount extruded for each line differently to adjust the "width" of the line.

[PSB]

@alankilian

Thank you. You mean I have to manually set the extrusion for each point where the width is different?

[alankilian]

@psb How are you creating the GCODE for your printer?

What specifically are you trying to accomplish?

There might be different things you can do depending on what you are trying to produce.

[PSB]

@alankilian
gcode will be created by the slicer. Lets say, this is one layer with varying width. Is there any way that the slicer can generate gcodes for this automatically. Probably anything we can do with the duet control system so that the slicer can generate the gcode for different extrusion ? I am quite new to this, if my question sounds stupid, I am sorry.
!

[rjenkinsgb]

@psb
I think you need to provide more information on what you are trying to achieve.

In general, if you create a 3D model in some CAD system, export it and feed it through a good slicer that is set up to match the printer mechanics, the output from the slicer will reproduce your design in the printer.

There are also other ways of producing the GCode program to send to an FDM printer, such as "non-planar" printing:
https://all3dp.com/2/non-planar-3d-printing-simply-explained/

The printer control system is no different, as a Duet or similar can move any combination of axes as required; however the "hot end" needs enough vertical clearance around the nozzle to avoid collisions, and the nozzle needs to be pointed rather than flat ended.
It's not a common system.

If you want ultra-fine detail, either you need to use a smaller printer nozzle (and set that in the slicer data), or look at such as an SLA type printer rather than FDM; SLA uses an optical system that gives far higher detail resolution.

[Phaedrux]

I think Cura is working on variable width extrusion for their slicer.

But I'm not sure how far that has come.

https://newreleases.io/project/github/Ultimaker/Cura/release/Arachne_engine_alpha

[PSB]

@rjenkinsgb Thanks for the suggestion. Imagine this as panel with a height of 20cm (the picture shows top view). This is what I want to achieve.

[PSB]

@phaedrux I will have a look. Thanks a lot.