Fast infill on narrow/long sections of a model causes printer vibration

[wiretapped 0]

I'm on v4.7.1 and am printing some models that have long sections (±100mm long) where the infill area (@ 100%) is maybe 3-4mm wide.

 

When the infill is printed, even at relatively low infill print speeds (20-30mm/sec), the Cura-output G-Code is printing the infill (Lines) in such a back-and-forth way (crossways to the length of the piece) that the printer essentially vibrates. The area being infilled is perhaps 3mm when the vibration occurs, but can also occur when it's even thinner.

 

Other than perhaps slowing down infill print to a much slower speed, is there any option to have the infill lines run parallel to the long axis (100mm) vs perpendicular to the long axis (±3mm) that it currently uses?

 

Would 'grid' help here?

 

At 100% infill I'm assuming there's not too many options but printing in tiny short runs at speed doesn't seem like it'll do the print job or the printer much good in the long run.

 

Potential for a future setting to select for longer infill lines in 'narrow' infill areas?

Edited September 30, 2020 by wiretapped

[wiretapped 0]

(Would a particular setting in "Infill Line Directions" deal with this?)

[gr5 2,265]

Firstly - most printers can handle the vibrations just fine.  It's just the nearby humans that sometimes have a sensitivity.

 

But to answer your question, yes.  You can change the infill angle.  In cura it's called "infill line directions".  You can have them all the same or you can have them at 45/135 (default?) or you can do 3 angles I think every 120 degree rotation?

 

This feature might not work with every type of infill (e.g. gyrloid?).  I'm not sure.  But I expect it will work with 100% infill.

[gr5 2,265]

Also note that you can rotate your part and the infill won't rotate.  So if you rotate your part 45 degrees then it will go one way along the part and the other way perpendicular.  But you can make all the infill go along the part if you use "infill line directions".

[GregValiant 1,409]

Constructive harmonics.  At certain frequencies, some things like to dance.  Your 3mm area at that particular speed is a sweet spot for your machine and I'm sure there are sweet spots for different variations of the printhead start/stop cycle.  I'm a believer in putting a printer on a heavy stand or table in order to damp the vibrations.  As gr5 indicated, changing the direction or speed will make a difference and could eliminate this situation completely, but this is the kind of thing that will reappear with a different model, different speed, different angle of infill or top/bottom mesh, etc.  Do a search for the "Galloping Gertie Bridge" and you'll feel a little better about your printer.  I understand why they call them "Constructive Harmonics" but "Destructive" would seem more appropriate.  All that swinging and swaying can certainly work it's way into a print.

Big heavy table.  Oak is good.  Granite too.  Cute bouncy 3d printed feet? - not for me thank you.

[wiretapped 0]

The printer's on a 1 x 1m cement block which is sitting on solid sponge.

 

I'll give the Infill Line Directions a go; thanks.

[GregValiant 1,409]

I was going to suggest you steal a granite headstone from a graveyard, but you have that covered.

[BlackboardIdeas 0]

Hey everyone, I think other slicers have a feature that changes the infill/top/bottom pattern for small areas to concentric to get rid of the quick back and forth movement. It would be great if the Cura community implemented something like this into Cura too, the vibrations almost defeat the point of silencing your machine with Noctua fans and TL smoothers.