Printing with PETG and PC; what causes this mess?

I don’t know if one can resign oneself to it just being the nature of PETG in general. I was able to get PLA-like smoothness with the Bambu white PETG but not their black. Also, their white PETG was not nearly as strong as the competitors Clear PETG when I performed a simple strength test.

The point is, and it’s a frustrating one, the formulas used in these filaments vary so greatly, the only certain way to know how a filament will perform unfortunately, is to do exactly what you’re doing, trial and error.

This is just part of the many annoyances I think we all face with the 3D printing industry in general. I used to think that the desktop print industry was rogue with their varied sources and quality of paper, that industry seems like tranquil waters compared to the 3D industry.

I assume one day this just might stabilize but I just don’t see that happening any time soon. There would have to be a sort of revolution and a trusted name like an HP or Epson would have to enter the industry before we saw a shakeout of these startups. Who knows, maybe Prusa might be acquired by one of those companies which would likely help the consumer in having a trusted source purchased by a brand name who equally wants to protect their rep.

Calibration has thrown up some room for change, specifically the flow ratio and pressure advance.

Retraction and temperature inconclusive, I couldn’t really see a tangible advantage in changing from the current setting to another.

Just waiting for Maxflow then I’ll try printing again and see if it’s made any difference.

Have the black PC arriving today so will repeat the process for that!

My experience having come to 3D printing only a few weeks ago is it’s close to plug and play for PLA, at least for this Bambu P1S but since I’ve started experimenting with other filaments it’s clear one must get their hands dirty.

If you need to print things solid (100% infill) then you had better have your flow multiplier calibrated perfectly as there is nowhere for the excess to go.

What is the correct way to print solid - I am doing 0% sparse infill density, and then setting high numbers for the top and bottom shell layers with top and bottom shell thickness set to zero (auto).

I’m not sure I’m doing it right though.

That will most probably result in a stronger part as it’s all outlines/walls. I’ll normally use 6 walls and 100% infill for a solid part because I like a plain surface top and bottom. Looking at your last pictures, that’s what I got when using auto flow calibration on the X1. Black ABS was 1.01% and mint green 90%, a huge difference between the 12 colors I did. When I printed black at that value it looked a lot worse than yours. I reprinted it again at 95% and it was perfect, I just use all defaults as I only use Bambu filaments now.

You can use this to 3MF to help you calibrate your ironing of PETG:

Google Drive

Google Drive file.

I usually skip right to the 30 mm/s plate.

It will simplify your ironing experience immensely.

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So I’d set Wall loops to 6, and sparse infill density to 100?

Here’s what I have now.

Thank you! I will get things as good as I can without ironing, and then move onto that.

This was awesome!

I can see straight away that my previous 30/10 setting is useless compared to the others.

So glad it helped. ; )
Also, another tip…
By default the ironing angle uses a diagonal ironing pattern.
In my experience horizontal/vertical patterns look better to me.

You can ,change from diagonal to h/v by using “45” or “135” in the Quality>Ironing>Ironing angle field (default is -1, which produces the diagonal).
In order to control whether it is horizontal or vertical in your model surface, slice with either the 45 or 135 and look at the layer under the “Preview” tab. If it shows the angle as the opposite of what you want just toggle the 45/135 value.
You can also see the in picture the top shell pattern, before the ironing angle, can be seen faintly… so that is another variable that can be tweaked to improve the final appearance.

If you want to use the h/v ironing in the ironing test 3mf, you will need to change that ironing angle value for each “modifier object” on the plate.

Great I’ll see how the current one comes out and then change the angle and compare.

According to the preview, an angle of zero degrees makes it horizontal in my model, so I guess it depends on the model.

Anyway, here are some before and after pics.

The one at the bottom is before is before any calibration or ironing-tuning, and the one at the top after is the latest (but still diagonally ironed - trying horizontal now!).

This thread has been enormously helpful, thank you to all!

Looking much better! Yay!

Just a point on your excellent ironing model - the only thing I found difficult was comparing adjacent blocks. This is because the ironing angle is alternating and when I was holding it up to the light to try and examine the difference in the texture/shininess etc they look quite different compared to each other simply because of the different angle.

I will be going through this process all over again tomorrow with my newly arrived PC filament as recommended by @Olias so I think with that one I will equalise the angles.

Yes. I have observed that myself. If you turn it 90 degree the light changes on it.
You could compensate for that by setting every other modifier 90 degrees different.
I will probably update my 3MF the next time I go to use it to do just that.

Would you mind sharing all your settings for the CC3D PC/PETG blend?

Otherwise, I’m unsure where to start - or do I start with Generic PC and modify from there?

Here are the parameters for glass-like outcomes. Note that one must use the profile on makerworld outlined in this post. Note, to get the glass-like appearance, I had to print it in 50% quiet mode.

Here is the generic profile I use everyday

This is the cooling profile used for both

Thank you - is that the PC/PETG blend?


These are the same filament.

From what I can tell there are two different filaments; the PETG one is pure PETG, and the PC one is a blend of PC/PETG/other.

To which one do your settings apply? The PETG one I guess?