extrusion settings on infill

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Mount PrintMore
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extrusion settings on infill

Post by Mount PrintMore » Sat Apr 19, 2014 3:31 am

I print a lot of parts with sections that are thin and flat. I print a variety of "calibration parts" that are essentially 25mm squares that are 0.2, 0.4, 1.0, and 2.6 mm thick.

I've settled on a strategy of using all default parameters in my config (0.35 nozzle, auto-extrusion width, 1.75 mm filament diameter). I typically run 90% infill, although sometimes I'll run 80% infill. I then run these calibration parts and dial the extruder override in the Creator machine control panel until I get parts that look right. Typically I take measurements with a thickness gage.

Something I've noticed is that no matter what I do to the extruder settings, it seems that my infill is "over extruded". As I dial back the extrusion override more and more, the outer perimeters appear to to impacted but the infill seems to be thicker. Usually, for the first 3 layers the infill looks like there are "tracks" in it where the nozzle has dragged through it. I can dial back the extrusion override so far that the perimeter passes no longer touch, and still have this rough texture in what looks like thick infill.

Does anyone have a clear understanding of exactly how the extrusion properties are controlled for infill as opposed to the perimeter layers? Has anyone else noticed anything similar?

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jimc
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Re: extrusion settings on infill

Post by jimc » Sat Apr 19, 2014 3:41 am

well im not sure how it will affect the perimeters and infill but you really need to set your filament dia correctly. the jog dials are for fine tuning while in mid print. they are not really how your supposed to set your extrusion rate. you should really get your dia and extrusion multiplier set correctly in the software so it can calculate the flowrates right.

Lateralg
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Re: extrusion settings on infill

Post by Lateralg » Sat Apr 19, 2014 4:31 am

Is there a way in S3D to change coast, retract, and extra start extrusion?

Do all the line-ending commands apply equally to infill, perimeter and solid?
Gary
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Lateralg
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Re: extrusion settings on infill

Post by Lateralg » Sat Apr 19, 2014 4:33 am

Is there a way in S3D to change coast, retract, and extra start extrusion?

Do all the line-ending commands apply equally to infill, perimeter and solid?
Gary
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jsc
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Re: extrusion settings on infill

Post by jsc » Sat Apr 19, 2014 4:56 am

Remember that your first few layers are going to be solid, so the infill percentage won't apply to them. If your first layer is rough, your z layer zero may be set too low. Once you get a rough surface, it will take a few layers to cover that up and get back to a smooth surface, and by then you've probably transitioned to infill.

Try setting your global extrusion percentage to 90% or so, first layer 100% layer height, and tweak your zero until it is going down smooth, with no overlapping roughness. You can do this on the fly, roughly, by clicking the z knob one click at a time; clockwise is lower, counter clockwise is higher.

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jimc
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Re: extrusion settings on infill

Post by jimc » Sat Apr 19, 2014 5:25 am

all those commands happen before or after a rapid movement on perimeter walls or infill. doesnt matter, if its a rapid its going to perform your settings.....well maybe "going" it a little too certain of a statement for s3d. how about "it should".

Lateralg
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Re: extrusion settings on infill

Post by Lateralg » Sat Apr 19, 2014 6:34 pm

jimc wrote:all those commands happen before or after a rapid movement on perimeter walls or infill. doesnt matter, if its a rapid its going to perform your settings.....well maybe "going" it a little too certain of a statement for s3d. how about "it should".
Thanks Jim; that gets me part way there.
What I still need to know is "Is there a way in S3D to change coast, retract, and extra start extrusion?" (On the fly, while printing)
Gary
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Dale Reed
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Re: extrusion settings on infill

Post by Dale Reed » Sat Apr 19, 2014 6:53 pm

Lateralg wrote: Thanks Jim; that gets me part way there.
What I still need to know is "Is there a way in S3D to change coast, retract, and extra start extrusion?" (On the fly, while printing)
Lateralg,

The coast, retraction and return are in the FFF (Process) dialog and are used in slicing to create the G-code. Once you have the G-code, you can't change those items on the fly. Nothing in the FFF can be overridden at run time.

The items in the MCP (Machine Control Panel) are applied at run time, and work with firmware features that can be adjusted at run time. The extrusion multiplier OVERRIDE (not the multiplier in the process) dial and the speed OVERRIDE dial insert G-codes into the data stream that change run-time numbers used by the firmware, but do not alter the G1 X..Y..Z..E.. codes being sent from your G-code file to the printer. Similar for the heater on/off control, the temperature adjustments, the fan slider and other items on the MCP.

The G-codes for the OVERRIDES are different G-codes from the ones generated in slicing. For example, retraction with Z-lift simply ADDS moves to the slicing-generated G-code: it inserts a reverse move of filament at some speed, lifts Z a bit at some speed, then the normal rapid move in X/Y takes place, then it inserts a the move of Z back to where it was and returns the filament (plus or minus the "extra return" distance), then continues with the normal extrusion move. The MCP has no ability to interpret these and add/modify/delete them at run time. Being real-time, it basically has to keep up with just sending the G-code to the machine! But it does sneak in the fan speed changes and such driven by your dinking stuff on the MCP dialog. Dinking the dials for extrusion and speed sneak in different G-codes, pretty much right off the dial setting, and the firmware takes care of the actual multiplication by those percentages as it generates moves.

So, simple answer? >>> If it's not on the MCP, you can't dink it at run time. Retraction, coast, return distance, Z-lift, etc., are on the FFF (Process), not the MCP, and are handled at slice (G-code generation) time.

Hope that makes it a bit clearer!
Dale

(edit: To see what the controls on the MCP actually send, go to the Communications tab and check the "verbose" box, then dink the knobs. You should be able to do this while the printer is idle... you can certainly do this with temperatures and fan speed.)

Mount PrintMore
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Re: extrusion settings on infill

Post by Mount PrintMore » Sun Apr 20, 2014 12:47 am

Why is it important to set the filament parameters in the FFF? What about the extrusion process is handled differently from a mathematical perspective if you set a filament diameter and extrusion multiplier in the slicing parameters versus using the override at run time? This is a question I've posted before at somepoint and the responses I got at the time led me to believe this wasn't an issue.

I tend to run copies of the same files over and over or in various colors, so I very much like not having to recreate my gcode files just because I put on a new roll. I literally run these calibration parts, take the measurements, write the override I want to use on the side of the spool with a Sharpie, and then swap around spools at will while running off various parts.

I'll get some pictures of the test patches and post them soon. Perhaps that will help spur some further discussion.

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Re: extrusion settings on infill

Post by jimc » Sun Apr 20, 2014 4:16 am

well yes thats fine to do that for different rolls but your fine tuning for the roll with the jog dials. you dont want to use them as your main extrusion settings. the difference is when you slice the part, s3d is calculating everything and its built into the gcode. when you use the jog dial its just sending an mcode to the printer and the firmware is doing the math now adjusting up or down by a percentage. does it make a difference, not for small fine tunes in mid print but to use the firmware to do the job that your slicer should be doing probably not the best way.

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