How to improve density and eliminate gaps in a print?

Hey all;

I am working on my first actual design-and-print project which is a cabinet replacement knob in ABS designed to take a #8 screw. The plan is to tap the hole but I may also just try a sheet metal screw directly. The basic shape is correct but the print always comes out with a gap somewhere in the exterior surface. I’ve attached a photo.

Also, what SLIC3R settings are best for trying to get as dense an infill as possible for the screw to be securely fastened?



What size nozzle do you have an what is your layer height? Looks like the filament didn’t stick on a layer and got dragged by the nozzle.
I would try decreasing the layer height and trying again.

Thanks. Yes I decreased it and it improved. Nozzle size is .35. A little more tweaking there will probably get it. But, I am worried about the support around the hole. Is there a strategy for making the inside of an object fill in as fully as possible? 100% fill?


I would adjust the overlap between infill and perimeter, but this isn’t an option in slic3r as far as I know.
You may be able to adjust the extrusion multiplier to fix the issue though.

You can adjust the infill density in slicer, 90% is sufficient for most parts.

It looks like the problem is that not enough plastic is being extruded; the most common cause of this is bits of filament clogging a few of the teeth on the hobbed bolt. The clogged teeth won’t be able to grab the filament, so the extrusion gets thrown off by quite a bit.

I’d check and clean the teeth of the hobbed bolt in the extruder, and decrease your print speeds a bit if the problem comes back. That should keep the filament from stripping.

You can also print at higher speeds without stripping if you go up to a .5mm nozzle. You’ll lose a bit of resolution, but the increase in speed and reliability makes it our nozzle size of choice here at AOHQ

Hope this helps!