I’m dialing in my little Printrbot Jr (v1) and noticing a problem I don’t see documented, and which I figure is pretty generic to most 3D printers. I’ve calibrated the heck out of the extruder, and I’m sure I have the filament size and so on set correctly in #Slic3r but it still seems to be extruding just a bit too much filament. What I’m seeing is that the nozzle is pushing plastic around (just a bit) and making the odd lump that ends up dropping off randomly on solid layers. It also seems to “mush” out the outside edges so that things like holes or teeth aren’t exactly the size they should be. Holes are smaller, teeth are “fatter”, etc… So obviously, I need to get it to extrude a bit less. The question is: Where is the best place to change that? Should I lie to it about the extruder calibration? Or about the size of the filament? Or what?
I know this sounds a little too easy, but try a different slicer. Slic3r is kind of known for derping out on small holes and making them too small.
I would start by double-checking the Z and extruder calibration. Make sure you are getting an accurate measurement of the filament diameter (measure in several places over a foot or two).
Anthony, which slicer do you like? I’m also not impressed with Slic3r for other reasons related to just wierd errors that I have to program around.
Steve, as I said, I have calibrated the heck out of the machine. Z and the extruder are as perfect as a human can measure. Dial calipers find no error. So now that it isn’t an error, where do you just reduce the amount of extrusion?
@Jeff_Karpinski That was exactly what I was missing! Thank you! I had seen it but apparently had assumed it did something else… not sure what. Brain fart. Thanks again.
@James_Newton Cura “recently” underwent a rewrite to use @Daid_Braam 's new slicing engine. It’s missing some advanced tweaking features, like bridge flow ratio, but it gets dimensions of things like small holes way more correct than slic3r.
I’ve now tried Cura @ThantiK . It sure has a nice user interface! Wow. I love the layer preview. But it does some wierd things with support structures. It printed a wall next to an interior void, which is fine, but it printed it way too close and so the filament bonded between the support and object walls and made it really difficult to remove the support. No apparent way to adjust that.
As @Jeff_Karpinski suggested, I dialed back the Extrusion Multiplier and and that has solved my original problem nicely.
It also turns out I probably wasn’t measuring the diameter of the filament as carefully as I should have been; it is slightly deformed and not perfectly round, so rotating the calipers made a difference. @Steve_McBride thanks.
Thanks much for all your help, I REALLY appreciate it!