Has anyone here managed to successfully print recently with HF PETG using a 0.8 mm nozzle? I’ve been trying for over 10 days now. I’ve attempted every possible calibration and gone through more than 10 spools of filament without being able to complete a decent print.
Support is practically nonexistent. I contacted them over a week ago, and they just reply once a day saying they’re sorry and keep asking me to print with another material (which, as I clearly mentioned before), I don’t have. I don’t know what else to do.
If you want, I can also help you rewrite this in a slightly more concise and “help-request” style that might get better responses on forums or social media. Do you want me to do that?
If you are looking for support here, it would be advisable to explain all the things you tested, what failed, and possibly images of the issues. The brand and type of filament is valuable information also.
The fact you wasted 10kg of filament, means you probably have been using parts for test, which takes ages and lots of filament.
All calibration tests require a minimum of material, and with 200gr. of filament you can do quite some tests.
I’m Having serious problem in parts quality by printing a Box using Bambulab PETG HF and 0.8 Nozzle.
In the past I used Normal PETG from Sunlu and decided to buy directly from Bambulab PETGHF in order print little bit faster.
Unfortunately prints come very bad and i tried every possible combination in slicing and calibration (Belt, extrusion, retraction, flow rate). But the box i need to print and even test objects still come very bad.
Are you using the stock profiles? I print with PETG hf using a .8 nozzle. I have a profile that is completely stock other than the layer height being .56. This is my “draft” profile and those prints come out way better.
It looks like PA is your problem. I let the machine calibrate this and it has been pretty good. H2c
Problem with such a large nozzle is that the maximum volumetric flow with a 0.8mm nozzle is not that much different than with the 0.4mm nozzle. So in other words, you don’t go much faster with a 0.8mm nozzle.
I am printing loads of PETG HF with a 0.4mm nozzle and don’t have any issues. Some of your issues seem to be cooling issues. The layer lines seem to be caused by different layer times.
If you performed a proper flow rate calibration (what is your current flow rate?), it would be good to print a temperature tower to see what the best temperature is.
I would for the time being start with the default profile and your validated flow rate.
Before printing a huge part again, make sure everything works fine on a smaller object. Saves a lot of filament.
There is a difference between Flow Rate, and Dynamic Flow Calibration (Pressure Advance). I would keep the Dyn. Flow on auto first, but do a Volumetric Flow Calibration. It’s also in the calibration menu.
First you need to solve your Flow Rate before doing any other testing.
Your adhesion issues might be caused by too low flow. But properly cleaning your plate with simple dish soap can help here a lot.
With those issues, its useless to continue further.
Work through the calibration tests from top to bottom.
Your limiting factor is the ceramic heater in your hotend, which is the same for all nozzle sizes. With PETG HF and standard hardened hotends you’re already close to the limit of the heat it can put out for a 0.4mm nozzle, you are able to exceed that with a 0.6mm nozzle, and easily able to exceed it with a 0.8mm nozzle. On that basis alone a 0.4 isn’t twice as slow as a 0.8 (and also, we’re taking area here, a 0.8mm nozzle has nearly 4x the flow area of a 0.4)
The actual difference is dependent on part geometry, but for my designs I generally see a ~20% time reduction with a 0.8mm nozzle versus a 0.4 when dealing with PETG HF.
Other filaments that are slower printing and/or have a lower printing temperature benefit far more from larger nozzles.
The other thing to consider is the high flow versions of a 0.6 or 0.8mm nozzle - they transfer the available heat more efficiently, so you do see more gains. The E3D Diamondback or Obxidian will show better performance with larger nozzles in PETG-HF.
The defect you mentioned is located at the seam. I’m currently using a “back seam”, but when I change the seam position, the defect simply moves with it. Could this be caused by retraction settings?
I print HF on H2C with 0.8mm nozzles, both left and right, high flow and regular. No calibrations (besides the auto flow at print start). IMHO in general everything on H2C comes out nicer if the speeds and accelerations are reduced (in project settings under Speed), and “Smooth coefficient” is reduced to a fraction (Quality → Advanced). But I’ve never seen it “that bad” even with defaults.
Dry it a lot. All the BL PETG I’ve dried usually looses 3-4 grams at least (HF, translucent, and now the “new” basic).
