Printing PETG

[jheikkila54]

Hey Guys,

I been printing with PETG for about 20 hours now and gotta say that I love it. It is very strong/durable, doenst warp, lift, or crack like ABS and isnt as brittle as PLA. It also has a higher density, so objects have that heavier quality feel to them. It took a but to dial in the print temp and retraction settings, get some strings but seems to be just one minor disadvantage.

I do have one problem, well sort of a problem, that I would like help diagnosing. Attached are 2 photos showing a 12 inch object that I printed standing up, has no infill, just 4 perimeters. You can see spots in the layers where the line makes an indent looking strech. Whether it underextruded there or it did something else, I would like to get this fixed.

[DarthRevan]

I'd suggest switching on "Coasting" and or "Wiping." Coasting stretches the last bit of filament at the end of a perimeter over the designated distance. Wiping will attempt to wipe excess filament that's oozing out at the end of your perimeter onto a non exterior surface.

[jheikkila54]

I have wipe on, set at 1.5mm. Might be to much or to little? Maybe play with coast instead or both.?

[DarthRevan]

are you using retract on layer change?

[jheikkila54]

Yes, raised .2mm

[DarthRevan]

Retract while wiping?

[jheikkila54]

Yup, I have that option checked as well.

[jheikkila54]

Also, just to be on the same page. I am using a .8 nozzle, .9 line width, .4 layer res, and printing at 30mm/s

[jimc]

yes #1 turn off the random start points and turn on choose start point closest to location. that will clean up the model and put them in a row so there is a seam. the petg shows these starts and stops worse because its translucent and you r looking into the plastic a little. once you collect them into a seam then you can see how you need to adjust your ooze control settings.

[JFettig]

I can't exactly see if they are a blob or inclusion - if its a blob, add some coast, .2-.5mm, if its an inclusion, do a longer wipe(5-10x the nozzle diameter).

Make sure your extrusion width is calibrated carefully as well.