Well as you probably know, there is no quick answer. No matter what anyone tells you or you may have read, this is not a question that can be answered definitively. There are too many variables that will affect the answer. The first of which is what do you want to achieve. Are you looking to use PETG for one of its specific properties such as Higher Temps, UV resistance etc. Or are you looking for more dimensional accuracy since you’re printing parts? Also, the humidity in your environment will also play a role as well as when the filament was packaged at the plant. If your date codes on the box are months apart, you could have two different moisture contents.
To save money on wasted prints, you’ll want to tune in a profile. This goes true for even the standard profiles that Bambu supplies, while good, aren’t necessarily suitable for all use-cases even with their filaments. I’ve found that I can generally get, smoother, more accurate and faster prints if I go through the hassle of tuning the filament profile.
Ironically, I have some Sunlu PETG arriving today because it was on an Amazon flash deal yesterday. So I may be able to give you a more specific answer later in the week after I tune my profile.
Here’s what I do with every new filament when I use it for the first time.
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Weigh it and write that weight on the spool itself. Then when it’s empty, weigh it again and write the weight of the spool and mark it as TARE and either keep the spool on hand for a record or maintain a log in a spreadsheet. While I don’t always dry my filament, with PETG which can be hydrophilic, if my initial tests show filament problems, I’ll dry it and then do a before an after weight. If you let’s say have a partial spool and weigh it before drying and then weigh it after, you’ll know how much water content was in it. Remember, 1g=1cc=1ml of water.
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Run a temperature tower(Up to 30 minutes depending on the range you dial in but worth the effort)
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Run a Pressure Advance test using the new PA Pattern which is baked into Orca.(10 minutes)
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Then I run a Max flow rate test to determine how far I can push the filament.(optional and I usually watch the test and cut it short when it’s obvious that I got to the filament limit)
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Last, I run a tolerance test using any number of tolerance testing models including the one baked into Orca, but the one I find the best is one that I created on my own using simple outer and inner rectangles. I then measure the tolerances based on what I designed in CAD and then dial-in the X-Y offset for both hole and contour.
If you’re building parts, then dimensional accuracy test is most important of all. For that, you can skip right to step 4.
This whole process will take a couple of hours the first couple of times you do it until you master it and learn the printer interface. Now I can do it in under an hour unattended just because I now know exactly what I am looking for. But it takes patience to learn how to do it and watching a few YouTube videos on Orca Calibration.