PETG Stringing

[ceramiclover]

I am fighting with a bad stringing issue. I have printed this many times, yet seem to be having this issue with the latest spool. I have used PETG from Overture many times before without such issues.
I have tried doing variable settings prints in which I have varied the temperature from 230-255.
I tried increasing the retraction distance in 1mm increments.
I increased the travel speed in 20mm/s increments.

I am using simplify3d V5 with a CR10 PRO

I am at a loss. Any advice would be appreciated.

[S3D-Jason]

Have you tried just going to Help > Configuration Assistant, and then re-downloading the stock profile for the CR-10S Pro? That would help see if the stock settings have similar issues.

[gwhite]

PETG is very "oozy" material. It gets worse the hotter you run it so operating at a low temperature should help. I haven't used the Overture filament, but I run PETG at ~ 240C. I still get occasional strings, but it's not bad.

If you just use standard retraction, it pulls the filament back, and then it pushes the same amount of filament back out when it starts the next pass. Material can continue to ooze down the nozzle during a move, so that when it tries to go back to printing, that extra material gets pushed out.

This is where "Extra Restart Distance" comes into play. A very small negative value tells the extruder to back off a tiny bit when it un-retracts the filament to compensate for the extra material that oozed down during the move.

I just checked the settings I have used with PETG (eSun & Hatchbox), and I have found that 2mm retraction and -0.05 to -0.06 mm Extra Restart Distance works well.

[wirlybird]

First and foremost is to dry the PETG. It absorbs moisture quickly. And never assume a new spool is dry.
I dry mine before every use.
Start there and see what happens.

[SimpleScott]

First and foremost is to dry the PETG. It absorbs moisture quickly.

Agree with this, 100%. When PTEG has absorbed water, bubbles form when it is melted in the print head, and those cause expansion and oozing, rough textures, and other issues. I have printed with damp PETG, and it looks just like the photos in OP.

Put the filament in an oven or dehydrator at 65C for at least 3 hours, and then give it another try. (If you use an oven, be careful -- most will NOT maintain a low enough temperature and can end up melting your filament or reels. A dehydrator or purpose-built filament dryer is best).

I keep mine in a dry-box with Dessicant, and the spool goes into a dehydrator during prints. When done printing, right back into the dry-box it goes. PETG (I mostly use Esun) prints beautifully when dry.

[S3D-Jason]

Just to check, are you only having the issue with this one spool? Have you printed fine using other materials or spools recently?