See the pictures below. Has this happened to anyone else before? It doesn't seem to be affecting the prints, but drops on the parts every so often. I have 3 printers, all with the same hot end and they all have this issue. Is it something I should be concerned about?
Do you happen to have yellow gearwheels in your extruders? Looks like mechanically dissolving mechanics.
Nope. There's nothing white or yellow on the whole assembly, outside of the thermal paste. But I imagine if it was the thermal paste, I wouldn't be the only one with this issue...
Is that independent from the material you use? What kind and make of filaments do you use? The idea that your printers take a line now and then can probably be ruled out... Any chance to install little collecting umbrellas above the heater to locate the origin more exactly? And has this been there all the time, or did it start at some time after dustless operation?
Yep, it is independent of the material we use, although we pretty consistently use MadeSolid's PET+, black. It has been there all along, noticeable a few months after we started using the printers.
I get some buildup that I accredited to abs, but nothing that severe. Might be a similar effect from the PET+
We've also seen a little bit of white powder specifically when printing PETG/Copolyesters. Seems to be all filaments of this type exhibit this behaviour, XT, T-Glase, Edge etc etc. We've sent some of the powder from E3D Edge off for analysis and talked to the people who formulate and compound our resins, they aren't 100% sure on exactly what it is, but they are completely sure that it cannot be toxic or harmful from their knowledge of the composition and the decomposition products. When printing ABS, some brands in particular you will get a small amount of sticky residue over time. This is styrene monomer that off-gasses from the filament and condenses on whatever it touches, it's slightly yellow in colour. This is what produces the characteristic ABS printing smell. Styrene monomer isn't nice stuff, but it's in such low concentrations that it's not something that is at all worrying. This is a nice article on the subject written by some very knowledgeable people. http://www.eastman.com/Literature_Center/S/SPMBS1615.pdf It looks to me what Garrett is seeing is a combination of deposits from PETG type filaments and Styrene that comes from the ABS. Both mingling together to get a mix of white powder deposit from PET and Styrene from ABS, which makes things look particularly ugly. Does this match up with the types of filaments you've been printing Garrett? Different types of ABS have different Styrene contents, which is why some smell worse than others and deposit more of the sticky stuff. PET type filaments seem to all be about the same in giving off this white powder.