[How to eliminate PETG strings?]

5 hours ago, Smithy said:

Thanks Smithy, I copied over the retraction settings. Was that all I should have copied or all the other settings? 

Fergazz, I downloaded a small retraction test tower and the pic attached shows the results. That was when I copied over the CPE retraction settings. 

I then printed more rings. the 4 inside the border are the ones with the new settings - still stringy but not as bad as the ones you see at the very top so there is progress! I did confirm that I did have retraction set before and the gear was definitely pulling the filament backwards. You can also see the heat, speed and fan settings in the other image. 

For the next print, I'm changing the CPE copied settings to 9mm retraction distance, 40 mm/s retraction speed and I lowered the filament temp to 230. I also sped it up to 70% instead of 60%. Is that the right idea or should I try something else? Seems it is an art form to perfect the petg anti-stringing settings. 

 

 

[How to eliminate PETG strings?]

Using Cura with a CR-10S.

 

PETG nozzle 240 and bed 75, speed 60. Nozzle is 0.4mm, which is the stock nozzle that it comes with. 

 

I enabled retraction at the suggestion of someone to eliminate the strings you see in this pic and it may have made it worse. It is just a circle with a flat flange at the bottom. 

 

Any recommendations would be greatly appreciated! 

[Layer on top of Triangles don't stick]

Thanks everyone for your feedback. I did get some petg and it works pretty good! I like that I can bridge 3 inches with hardly any sag. 

 

Resolution is not critical for a few of my projects so am using a 0.6mm nozzle. 

 

The petg is not sticking well to the triangle infill very well. Much better than abs, but not as good as I think it can be. 

I'm using 245 nozzle temp and 75-80 bed temp. Speed can do 100-200 mm/sec for most of it, but I slow it down to 50-80 when it is printing across the top of the triangle infill. Any suggestions on tweaking these settings to help those layers stick better? Attached are a few pics of the petg. 

 

Also, it gets a bit stringy - is that a retraction setting issue for when it moves from one spot to another without printing? I'm using the simple recommended settings in Cura to select nozzle size and density and have not done the custom settings yet.

 

Thanks for any help you can give. If I have to build an enclosure to print petg better, I can do it but then I might as well go back to abs since it is much stronger than petg. 

I also ordered polymax - polycarbonate filament that can work at temps similar to petg - will get it early next week. 

 

[Layer on top of Triangles don't stick]

Smithy, thanks for the reply. I just ordered some PETG and will test it out. 

[Layer on top of Triangles don't stick]

Another try - you can see the layer trying to cover the triangles just doesn't stick.

[Layer on top of Triangles don't stick]

When printing the bottom layer, it sticks fine to the bed and it prints the triangle layer. When printing the flat layer across the top of the triangles, it prints then curls up quick and doesn't bond to the triangles. Any suggestions? 

 

I'm using the latest Cura with a CR10S - ABS - filament temp 225 and bed 80. Nozzle is 0.4mm.

 

Any help would be greatly appreciated!