i3, excess material near infill borders

Hello, i have this issue which i never was able to readuce 100%, its like near the end of an inflill line, it pushes a bit of excess material to a side from the previous line, reducing extrusion multiplier does not seem to be the right fix, since it also causes small gaps between infill lines. Im using a 0.5mm nozzle, near 70mm/s top speed, slicing with simplify3d

What controller/firmware?

Looks like [marlinfw.org] or [duet3d.dozuki.com]

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MBot3D Printer
MakerBot clone Kit from Amazon
Added heated bed.

Leadscrew self-built printer (in progress)
Duet Wifi, Precision Piezo parts

Latest Marlin stable, with drv8825 in RAMPS

Slow down, reduce infill overlap, increase layer height(with baby stepping to get at least one smooth layer), reduce extrusion to 95%
stop nozzle rising on direction change.

Try bumping up acceleration until loosing steps then back it off a bit until stable, then try bumping up the jerk setting. That worked for me.

It's basically due to nozzle pressure not being able to adjust rapidly enough to account for slowing down due to direction changes and how fast it can do 180 degrees turns, which is what solid infill is. So to fix this you can try making the nozzle spend as little time doing cornering, at as close to the speed you're doing infill.

To a lesser degree the way the bed is mechanically mounted can also play a role. When mounted on springs, any back and forth motion will dip and rise the bed slightly and bounce as you can see in the extrusion lines. Replacing the springs by shims will help to some extend. The i3 mechanics aren't really good for higher speeds than 40mm/s tops.

As mentioned, the new default setting for infill overlap is 25%. It used to be 15%. When I dropped down to 15% it improved a lot though some gaps may start appearing if there's too much compliance/backlash. Even without compliance gaps may appear.

At higher speeds filament tends to cut corners too, so the too of 'hearpin' corners may draw together, bunching them up.

The bigger the nozzle the higher the tendency to ooze and leak. Try 0.4mm nozzle and see if that improves it.

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Kind regards
Imqqmi

NFAN CoreXY printer:
[reprap.org]

thanks MechaBits/imqqmi I'll try all this and report back. Thanks

Maybe it is just me, but...

I notice that you're using white filament. I have used three different, good quality manufacturers' filament and whenever I use a white filament my surfaces look like crap. Swap out the white for another color and all is perfect...

Has anyone else ever noticed that white PLA prints poorly? What is the secret for printing white PLA?

Thanks,
DLC

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Kits: Folgertech Kossel 2020 upgraded E3Dv6, Anet A8 upgraded E3Dv6, Tevo Tarantula enhanced parts and dual-head, TronXY X5SA Pro(E3DHemera).
Scratch: Large bed Cartesian, exchangeable heads, Linear slide Delta, Maker-Beam XL Micro Delta, 220x220CoreXY.

@ luismanson: check your slicer - parameter infill overlap --> this defines how much infill and perimeter do overlap. Usually I use about 15% - seems like your overlap is set to high.

@dlc60: strange. I used a spool of white PLA filament a while ago - was no different to the other colors (I nearly only use PLA, only very seldom PETG/TPU/PA6.66)

Edited 1 time(s). Last edit at 11/21/2018 05:08AM by Dancer.

@Dancer, its on 20%, i don't know if i should decrease this, since the problem only manifest near borders where every fill line ends.

I was able to perform just a single test, but reducing speed did improve a lot the final quality, there are still room for improvement.

Yes, I would try to decrease, because as I wrote: this defines how much infill and perimeter do overlap - that is exactly at the ends of every infill line.

I was confusing this with extrusion multiplier, sorry.
I'll give it a try