Hi everyone, I’m looking for advice on a set of problems that showed up while printing PETG on my Sovol SV06 Plus ACE (0.4 mm nozzle). I had several successful prints earlier, but after switching PETG brands and tweaking temps/speeds, the print quality fell apart and one print suddenly shifted 2 mm on the X-axis mid-print. Here’s the full situation.
Symptoms
1. PETG constantly oozes from the nozzle, even at low temp
At 200–240 °C, the nozzle produces long, continuous strands of molten PETG even while idle.
The nozzle slowly forms a “hook” of filament that keeps growing.
Not just normal PETG drool — it continues extruding without extrusion commands.
2. Large blobs form on the print
These blobs appear to originate from molten plastic collecting on or above the nozzle.
Blobs get deposited onto walls and sometimes build up into solid bumps.
3. Sudden 2 mm shift in X direction mid-print
Layers above a certain point are consistently offset by ~2 mm.
The shift is exactly one GT2 belt tooth, suggesting a missed step or belt skip.
No obvious loose belts; both X and Y feel properly tensioned.
Streaming molten PETG may have caused the nozzle to hit a blob and skip a step.
4. Nozzle exterior looks crusty and burnt
The hex faces of the nozzle have hardened PETG residue.
Strongly suggests filament leaking above the nozzle tip.
Printer / Slicer Setup
Printer: Sovol SV06 Plus ACE
Nozzle: 0.4 mm brass
Material: Overture PETG (230–250°C recommended)
Bed: 80°C
Firmware: Stock
Slicer: OrcaSlicer 2.3.1 on macOS
Speeds (for PETG):
Outer wall 35 mm/s
Inner 55 mm/s
Infill 60–70 mm/s
Travel 180 mm/s (later lowered to 120 mm/s)
Changes made before problems:
Increased nozzle temp from ~215°C to ~238°C
Dramatically slowed print speeds for PETG
Adjusted flow (Flux) by –2% during a print
What I suspect
After reviewing everything, it looks very likely that the nozzle is leaking at the nozzle–heat-break joint.
This would explain:
Continuous oozing
Crust buildup around the nozzle
Random blobs on walls
Nozzle strikes → skipped belt tooth → 2 mm print shift
PETG dripping even when hot but not printing
But I want more experienced eyes on this.
Questions for the community
Does this look like a classic nozzle/heat-break leak?
Is it safe to try a hot-tightening procedure at 250°C on this printer?
Could the 2 mm shift only come from a nozzle crash, or should I inspect belts/pulleys anyway?
Are these oozing behaviors normal for Overture PETG, or is this definitely mechanical?
Is there anything else I should check before reprinting a large part?
Photos (I wanted to add more pics but since I’m new here I can only add one for now. More available on request)
If anyone has dealt with this exact combination of PETG oozing + nozzle leak + sudden layer shift, I’d appreciate your insights. I don’t want to waste more PETG or cause damage, so I’m hoping to get the root cause nailed down before printing another large piece.
If it was a heatbreak leak, you would have filament in the sock.
PETG is known to ooze, there is really no way around this…
this is why the nozzle wiper is there, but it doesn’t always do the job.
It is a good idea to turn on Skirt Loops, at least 2-3..this way any ooze can be caught & stick to the plate. Most of the time this will catch the ooze just fine, every know & then it will land in the first layer..so if your watching it you can pull or cut if off before you have to stop the print & start over.
The burnt filament on the nozzle is a known PETG issue, PETG wants to curl back up towards the nozzle. So after every PETG print you want to use a brass or silver brush to clean off the outside of the nozzle..other wise other filaments will stick to the PETG on the nozzle.
Thanks for the detailed reply — really appreciate it!
To answer your question about the shift: This only happened on this one print. I’ve printed the same model before using Sovol clear blue PETG, and that run actually surprised me because I accidentally left my PLA travel speeds extremely high (much higher than what I’m using now). Despite that, the clear blue PETG print succeeded without any layer shifts.
This most recent failure was my first time using Overture red PETG, so I updated the temperatures to match the manufacturer’s recommendations and also dropped my travel speeds significantly to better suit PETG. The brim and the first several layers came out really clean and tidy, which made me think everything was dialed in properly.
As the print got taller, though, I started noticing occasional blobs appearing — not constantly, but enough to make me pay attention. It seemed like the oozing was a bit more aggressive than with the Sovol PETG, and I was planning to adjust settings on the next run. Unfortunately, right after I stepped away for about 15 minutes, the entire print suddenly shifted by about 2 mm in the positive X direction, and from that point every layer was misaligned.
Since I’m still new to 3D printing, I wasn’t sure whether this kind of sudden shift is something that just “sometimes happens,” or if it’s a sign of something mechanical (like a belt skip) or slicer-related. I’ve never seen it happen before on this machine, and this was the only print where it occurred.
Happy to provide any other details if it helps narrow things down!
Once you start posting more that limitation will go away…sorry, I don’t remember the number of posts. Go ahead & post them one at a time until it lets you attach more.
I would like to see a top view of the red print above, along with a completed blue print.
I’ve never used Overture PETG, but since the Sovol PETG printed without any issues I’d say that it is temp related.
I print 99% of my PETG at 235*, I’ve only had to adjust that once for a filament that required 270*.
I would try again at the lowest temp posted at 230* & work your way up 5* until you find the right temp (Overture PETG (230–250°C recommended).
Yes, you might have some crappy prints, but this is 3D Printing 101.
You nozzle doesn’t look as bad as you described, it looks fine to me.
The oozing is just something you will have to get used to, just pull it off before the bed levels & right again after if your fast enough
I thought the 1st pick had supports in it, but it was a little blurry…
My guess would be that the nozzle hit the supports & cause the shift…
I don’t see any infill in the model…BTW, never use Grid infill for this reason.
Why did you choose PETG for this model, will PLA work, it would be easier since your just starting out.
I chose PETG because it’s going to be an attachment to a cup holder for a car seat so I needed something that can withstand higher temperatures and impacts from kids.
That part that shifted is a sleeve that fits over the cup holder.
If it was just a bump like you say, maybe I was just unlucky and I should try the print again.
