Build plate messy when printing with PETG

[Adventurehill1 0]

My printer just finished a 27 hour print, but I'm wondering how to improve it throwing random plastic all over my build plate. I'm not sure how it manages to do it, but it's nasty.

oem velocity stack.3mf

[jaysenodell 17]

I only get that when something has gone “missing” and the extruder is printing into nothingness. This is normally a support vanishing or a part from a multipart print moving to a new location. Some telltale signals for me are lots an extruded material on one edge of a part. 
 

Another possibility is a series of large bridges that are failing in the first couple layers. This should be pretty noticeable as poor quality finish. 
 

This is the kind of thing that timelapse camera systems really help solve. 

[Adventurehill1 0]

The model itself printed beautifully, except for the infill. It is a grid pattern, and it seems to bunch up at the intersections of the grids and leave the lines between corners empty. It did have a lot of stringing on the model, but I know that's somewhat a PETG thing.

[jaysenodell 17]

Sounds like your infill likely isn’t solid and all the mess is infill booger string that got pulled off the model and fell to the plate (stuck to the noz and got knocked off). Not a petg thing but a too fast thing from my experience.
 

Even if it is just petg strings still a speed and extrusion problem. @Slashee_the_Cow is a go slow advocate and following her advice I’ve managed to eliminate much of my “it should all stick” issues (with the exceptions of supports which @GregValiant fixed). It all comes down to giving the material time to stick and cool before you pull it off with a direction change. 

[Slashee_the_Cow 382]

Worth remembering that the Speed > Print Speed setting in Cura will make the infill print at that speed but everything else at half that. Seems pretty stupid IMO but I didn't design it so whatever. In many cases it's not a huge problem since the infill doesn't need to look pretty, but set it too high and you can exceed what the material can manage.

 

Problem is, I've seen people set the print speed setting really high because they see their wall speed isn't very high (I can see why they're coming from, which is why I think it's stupid) meaning the infill goes at warp speed. I generally set all the speeds myself and save them in profiles for different materials.