PETG collecting on nozzle

Hey guys, I finally got my PETG dialed in, and am printing some great parts. Here, I am printing about 36 tank treads for a rover I’m going to start soon, however, as clean and accurate as the parts are (really happy), you can see that I’m getting unsightly buildup on my nozzle.

My biggest fear (and have experienced it already) is that a glob will catch on one of the parts and leave a mound of plastic behind. So next time the head comes by, well, its not pretty.

Here are my specks:

Nozzle: 240
Bed: 80
Filament size: 2.88
Flow: 100%

Part is being printed at

Layer height: .25
Fill: 40%

I have found of all the filaments I’ve used so far, PET is the biggest pain to get off the print head. It does gum up on there, and at least on one of my printers would occasionally leave a little bleb. Though oddly enough, it was extremely rare for it to leave it on the part, it always seemed to leave it on a string. On the Taz5 at least, I ran 3 rolls of clear PET over the course of a month, and while the head looked like crap from all the melted plastic, it never left a problem on the parts. On my other printer, a Makeit pro, I would get them, but they popped off the parts pretty easy as they never seemed to drop off in the middle of the print, but on a side wall. Though I will say in looking at your picture I’m not sure I ever had that much of a build up around the nozzle.

Go to your local supermarket or home improvement store and get some Scotchbrite pads, green color and found in the dish washing or cleaning departments. When the nozzle is hot just wipe as needed. Caution the nozzle will be hot and you could burn your fingers.
Been using them for over a year, toss out when worn or full of plastic.

If you have so much buildup, i would recommend you to check your esteps calibration. I guess you are over extruding. PETG is the last forgiving material when it comes to over extrusion,you have to be precise!

Nailed it! Check out the image. After catching some insight from another page (posted in a separate post), I started adding .1 increments to my Z. Offset, thinking, either I would eventually get the head to stop the buildip, or eventually loose adhesion.

Well, adhesion is working fine, and the nose is completely clear of buildup at 50% of print. By now, if have a glob that would threaten to release.

Ended up adding .3 to the Z offset. (By incements of .1 per attempt.


My esteps are dead on, that was one of the first things I adjusted :slight_smile:

thanks for z offset tip. Havent used this before but will try since having same exact issue of nozzle buildup. Since this is controlled in the machine settings, i guess you can’t keep it with the material profile, so have to remember to reset it every time working with petg?

.3 offset works well. still getting some buildup but much less than before :slight_smile:

Sweet. You can increase offset. Like I said, until you lose adhesion to the build plate, you can keep going. Also, you may try compensating if you do loose adhesion by trying to increase the initial layer height something like 125-150%.

cool. i settled on 0.15 offset. most of the buildup occurs at the beginning when trying to get the first bit of goo flowing smoothly and sticking down, if i deal with that with the tweezers, then rest of printing goes well with the minor offset

PeterT, Thank you for the information in this post. I had exactly the same problem, and by increasing my Z offset by 0.1mm it completely resolved the problem.

Also, since I happened to be printing with some fancy translucent red color filament, I notice now the color matches almost perfectly what I’ve printed vs. what was on the spool. So I must assume I was dragging the nozzle over the filament that was already laid down, previous to raising my Z offset.

I am using Makergeeks PETG; had i working perfect with .35 tip, but needed a little more speed in my prints time-wise I am using v4 hot end

So i purchased a .5mm. Changed the settings that needed it for .5mm nozzle, but my prints are now getting tons of strings

I have tried with and without retraction, since I have read it can cause this, with little change

and tweaked my ooze control a little, to no avail

Any ideas?