I dial my Z offset back away while printing because it looks like my nozzle is too close but once I get far enough away to avoid what appears to be nozzle drag marks on the infill, I can clearly see I’m now too far away and my lines are barely touching (if at all). Tough to find that sweet spot. This was one of my earlier layers a few mm into this print before I backed off my Z offset a bit
That flow is way high. It shouldn’t be leaving drag marks like that throughout. White filaments always print oozier for me due to lack of fillers. I tend to print them a bit cooler and at like 97% flow.
This.
White filaments should have the same or similar amounts of pigments in them as black or other colour filaments. Only clear filaments has no or very little additives. Its pretty weird that you notice a difference, are you sure?
I have purchased 68 rolls of white filament.
Yes I am sure.
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Thanks I’ll try backing down on the flow!
Weird, I wonder why that is.
It is likely due to whatever chemicals they use to make the white pigment cooling slower. That said, let me science the shit out of heat and colors…
Ever notice that people who live deep in hot deserts actually wear black clothing instead of white? Even the human body develops more melanin to make the skin darker the more it is exposed to the hot sun. Seems like a shitty adaptation at first glance, darker colors absorb more heat.
However, eventually the saturation point of every material, regardless of color, is going to be reached and 150deg will be 150deg regardless of color. Except while white is the slowest color to absorb incandescent energy it is also the slowest to release energy back out of it.
Going back to the desert example, white will heat up to that 150deg eventually and sit at that temp as long as light is continuing to be applied. Black, on the other hand, releases energy much quicker and, while it initially heats faster, will peak and maintain a much cooler temperature than the 150deg.
The release of energy occurs regardless of the initial source, whether it is from light or a printer heating element. White cools off slower.
Science. 
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Thats usually titanium dioxide. Black is pure carbon usually. I get that black cools off slower, makes sense, black body radiation. But that won’t have any effect on oozing, as the nozzle is held at a constant temperature. Maybe white pigment makes it a bit more runny?
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Yeah oozier/runnier is a good way to describe it
Going back to the desert example, white will heat up to that 150deg eventually and sit at that temp as long as light is continuing to be applied. Black, on the other hand, releases energy much quicker and, while it initially heats faster, will peak and maintain a much cooler temperature than the 150deg.
It depends on a lot of factors, but this is generally not true. The majority of the sun’s energy is in the visible spectrum which white paint reflects well and black paint absorbs well. Both of them at any reasonable temperature are emitting most of their energy in the far infrared. White paint can actually be just as good at emitting and absorbing far infrared as black paint. For that reason, all else being equal white paint will normally lead to a much lower temperature than black paint.
Even with heating things externally like in 3d printing, I don’t think it’s a given that white cools slower, though it’s certainly possible. At 3d printing temps the emissions are still going to be far in the infrared and so how well the object radiates heat as light depends mostly on parts of the spectrum very far from visible that we can’t really infer based on color.
At least that is my understanding. I know the old “white things cool slower” thing that is said, but I actually don’t think that is necessarily true from learning physics. The real answer afaik is that you can’t really tell much about radiation anywhere near room temperature by color.
Edit: Actually I think saying “The majority of the sun’s energy is in the visible spectrum” is actually wrong. That is the peak, but I think most of the energy is still outside the visible. I guess I should have said the energy from the sun is the highest in the visible spectrum.
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Now, do you know anything about titanium dioxide making things runny?
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Maybe it’s lactose intolerant
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Not really, though as a pigment I think it may require more colorant than other pigments, and the more of a colorant you need to use the more you’re likely to have properties shift away from the base ones. There is actually a ton of complexity with coloring plastics though and I’m not very knowledgeable.
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If you actually need more white pigment to make plastic white compared to other pigments then that might be our answer, although I never were under the impression that ratios actually differ drastically, so much that the actual material properties are affected. Kinda makes it not a very good pigment then.
Ok folks - PETG. What a fickle bitch. Trying to get into printing this now but it’s a pretty different animal than PLA or PLA+. Am I screwing myself using a 0.6 nozzle with this? So far running it at 30-40 speed, 230* with 80* bed and it’s a runny blobby mess. Stringing, poor layer adhesion (if I go over 0.2 layer height).Tried backing off the flow based on my previous PLA prints but still not a lot of help. Keeping fan speed to 50% or less (it’s at 0% for first few layers). What else should I be looking for?
I’d look at your retraction distance and speed next. You’ve slowed it down and turned the fan down/off which were my 2 other suggestions so you’re on the right track!
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Great, thanks. Anyone have luck with the coasting setting in Cura? Seems like it could be hit or miss and a pain to dial in. I saw a video on YT mentioning the minimum layer time also, giving the just-printed layer time to cool before slopping more goo on top of it.
I misread this as coasting as combing but typed out a nice response so fuck it, I’m sending it.
This one is really hit or miss depending on filament an the print in question.
One the plus side, it reduces retractions and travels the unretracted nozzle head over already printed points, hiding some ooze.
On the negative side, it makes long movements to get to the next point where it starts printing and if you are oozing AT ALL, it can leave ugly marks on walls and draggy areas.
This one I use all the time. It can be worked around if you tweak with k value/linear advance stuff but that seemed like more effort to me than changing a setting and running a few test prints.
If you want a generic number to start out with (use pla, don’t try new settings out for science on unknown filaments), I use 0.064mm^3 coasting volume and 90% speed. 0.8mm^3 minimum volume before coasting.
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I use prusaslicer so no idea, but these are my speeds (on my prusa) which work okay on my 0.6mm nozzle:
idk if cura has this setting, but to avoid unnessecary stringing I turn on “Avoid crossing perimeters”, this helps a ton. You will almost always have some stringing with PETG though. I also run PETG at 220°C, that also helps.
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Thanks for the answers to both lol. I’ll try that out on PLA and see if it helps with any overextrusion bits at the end of print lines