Small prints ok, big prints have issues.

[boeing7873 0]

I have been battling with PETG quality issues. Mostly under extrusion, poor adhesion, and oozing. I can pretty much solve all issues on small test objects, but when I slice my current project, a 12 hour print, problems surface in many areas. Oozing, sometimes a random layer under extruded, blobs in random places... much of the oozing happens in the support. 

 

What can change from small to big objects?

Thanks!

[Carla_Birch 116]

A few things can change between small to big prints.

 

Heat creep in the hot end is one that can affect how the printer will extrude, if the heat builds up into area's of the hotend it should not do.

 

Pressure within the nozzle can change going from model to model.

 

Blobs can be build up on the nozzle coming free, PETG likes to stick and normal you start a print with a little bit more of a gap between the print bed and the nozzle.

 

Posting, photos of the prints and also what printer you use and your settings can also greatly help people to be able to able to help you, as sometimes it can be the most basic setting that could make problems.