3D Printing With PETG

When I bought my 3D printer I knew I wanted to print with something more durable and heat-resistant than PLA. PETG was the obvious choice, as that was what many folks on the internet said was becoming the new PLA. One very real downside with PETG though was the fact that it was a lot more finicky to print with. The first photo below shows how a skirt came out, not sticking to the bed at all.

The next photo shows the globby infill.

Next is a photo of the start of a PLA print when I was having the same types of issues with PLA. The brim was ratty and the edges of the features were horrible. I did manage to later get the PLA settings right.

Needless to say, I was a bit disappointed when my PETG prints were turning out less than mediocre. Even the filament barely stuck to the bed during the first layer. It would just get dragged around with the hot nozzle. Going to the internet gave some hope, as people said that once you get everything figured out, PETG prints come out nice. So I started fiddling, but there are so many different variables, it is hard to find the right combination. I think I've finally honed in to a workable group of settings though. This next photo below shows my most recent project, a chip guard I had designed in Fusion 360 way back when I was using my daughter's printer for the first time.

Here is a link to the first chip guard I made from PLA. Yes, it's purple, my daughter's color choice of filament.
Atlas 618 Chip Guard

The settings that proved to work well for PETG (the most game-changing was to slow the print speed down):
- Temperature: 240C first layer, 235 subsequent layers
- Bed 80C for first few layers, then no heat (maybe some heat for larger projects)
- First-layer speed 30 mm/s, then bump up to 40 mm/s
- No fan for first layer, then introduce fan
- Disable Acceleration and Jerk (Cura)

Using the above settings, the skirt and first layer stuck beautifully to the bed, and the part ended up turning out very nice.

I'm sure I'll tweak the settings more. I can hopefully get away with upping the print speed to 50. At 60 infill was balling up. Maybe I can use 60 for outer walls and 50 for infill, I don't know. So many variables....