Infill Quality - Low

#1
Hi, hopefully someone will be able to give some advice on this.

I am playing around with settings in Cura, trying to get the best quality print. Up until yesterday, I was only familiar with Slic3r (but it was causing me issues). So far, everything is going better with each attempt. One thing that has remained the same is the infill. I raised the infill density from 10% to 20%, and I tried fiddling with some speed and thickness settings. My next attempt has the infill changed from grid to triangles.

What's happening is I end up with a very broken infill. The lines are often incomplete and rough looking, they don't connect in many places. Lucky for me the model I'm printing is only for display, but I'm curious if there's a way I can produce better results? The part ends up being extremely brittle and easy to break/separate. I have attached pics for your viewing pleasure. Thanks!
 

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#5
One thing I have noticed is the nozzle diameter plays a big part in how well it can do certain things. If the infill is too fine a detail, the printer will try and lay it down, but just can’t handle it. I have dabbled in Cura a little bit, but mostly use simplify3d, the print preview feature is great, because you can zoom in and see if a line is going to go down how you want it to. for example, if your extrusion width is too .8 mm, and the width of your print is 2 mm, you’ll see a gap where the printer can’t really fill in because of the print width.
 
#6
Thanks stcipad, I appreciate the info. I typically run an extrusion width of between .1 and .3 mm, but lately I have been going steady at .2mm. The single J-head I have is a .5mm, and I read a few articles suggesting to run your width at 20% of the capacity. 0.1mm seemed a little too fine though. I typically run a print width of 0.5mm. Should I be running different numbers for these parameters?

There is a print preview mode in Cura, but the zoom feature is absolutely atrocious. As far as I can tell, there is no way to pan or shift left or right once you're zoomed in which makes it nearly impossible to observe fine details in the preview. There may be a way to do this, but it is not the standard methods you would use when running 3D rendering software. I looked into simplify3d and it does appear to be quite versatile, but as I am just a shop manager at a company that utilizes the printer I am unable to make a purchase like that without authorization.
 
#8
What happens if you go up to 40% infill?

When you you say:



Do you mean height? because earlier you mention between .1 and .3 mm
Hey stcipad, sorry I was a little unclear there. I run a layer height of between .1 and .3 mm, and a line width of 0.5. It was recommended on a couple guide pages that I should run my line width the same as my extruder size and then run my layer height at 20% of that.

If I go to a higher infill %, I end up with a much stronger wall but typically I don't see much change in the infill quality. It should be noted that this is hit or miss, sometimes I get quite decent infill lines and other times they end up like the ones pictured above.
 
#10
I would have to say they tend to vary print to print, but one thing I have had huge issues with in the past is the Babystep Z being very inconsistent between prints as well (of the same model). It always seems to need to be tweaked to a different number even after leveling the bed. I finally figured out how to save my Z step settings in the firmware and this made things a lot better, but my first layers tend to always be nearly invisible or too far from the bed while every subsequent layer (minus the infill) seems to be in good shape. Not sure if this is a related issue, but I am always tweaking the Z step and the extrusion settings, chasing a solid first layer. I thought that the infill has something to do with retraction or travel speed or maybe infill speed, but playing around with these settings hasn't changed things much. I do feel like the saving of the Z settings in the firmware gave me reasonably better quality infill. Not perfect, but better.
 
#11
You have the heated bed, right? Are you heating both zones all the time? I had a similar issue until I made sure I leveled the bed with both zones on and at temp.
 
#12
At first I was only using the inner bed for printing so I had it on and left the outside zone off, but because my inside zone is pretty worn now I have been using the outside zone and heating both beds. I do feel like I'm getting a slight difference in infill quality now, but I can't say when I started using the outer bed or whether I noticed the change afterwards. That's interesting though, is it just due to a more evenly heated surface?