Polycarbonate and line width

Scottbg1

I have been trying to perfect my printing of polycarbonate. I am getting pretty decent results but I found myself searching for tips and tricks today and I came upon this Reddit discussion on the subject and it's a little bit fantastic and before I started changing my slicer settings and wasting PC filament for nothing, I wanted to get an opinion here.

The OP posted a photo of a beautifully printed part made of Polycarbonate.
He stated that he discovered PC printed best when he changed the line width in his slicer to .9mm while using a .4 nozzle.
He stated the strength also improved by a great margin by doing this.

Here is a link to the discussion:
https://www.reddit.com/r/3Dprinting/comments/8edmdc/perfect_polycarbonate_prints_5x_nozzle_diameter/

Thoughts anyone?

Phaedrux

I've seen that reported before in the Prusa forums.

I think the theory is that polymers will bond due to heat, but also pressure, so increasing the extrusion force apparently results in a better bond to the layer below.

I have not printed PC myself, though I'd like to.

nophead

I think the more relevant metric is the ratio of line width to layer height. That is what sets how squashed the filament is and that does affect bond strength.

Nozzle diameter isn't even a parameter in the slicer I use. It only really affects the range of line width / layer height combinations that will work. It doesn't enter into any of the extrusion calculations.

Scottbg1

@nophead said in Polycarbonate and line width:

Nozzle diameter isn't even a parameter in the slicer I use. It only really affects the range of line width / layer height combinations that will work. It doesn't enter into any of the extrusion calculations.

This.
I use Simplify 3D and it only allows to change the width on the first layer.
Cura allows for line width changes though.

I guess I need to brush up on my Cura skills.