PETG , Print starts to go bad after a few layers.
Hi friends, I have been having issues with my prusa mini since I have gotten it (installed a bondtech extruder on it before first print) in regards to petg. I printed with the PLA it came with after doing the setup and the Prusa logo printed fairly okay. I bought some petg on amazon (house brand) and figured it was an issue with that so purchased some prusament petg. Bought a filament dehydrator and still issues, tried setting the pinda probe with a credit card (slides under pinda with little resistance) . So as I do a print it seems like my nozzle adjusts but does not adjust as much as it should? Prints end up build "fuzzies" as it goes higher and higher eventually becoming a mess. Now this is just with my eyes but it seems the nozzle is etching into the previous printed area?
250/90 when full print is going, 170/85 to start. Tried slowing speed to 90 from 100 but doesnt do anything. I have it printing right now, started at -1.740 Z and im at -.455 now as I have to manually adjust (Will not save the print I just seem to be going longer than before if I keep adjusting the z offset closer to 0 as I print. Thanks guys.
Please show us pictures of your first layer Z calibration print and of a typical failed print, top and bottom.
Cheerio,
RE: PETG , Print starts to go bad after a few layers.
https://postimg.cc/gallery/vMkvzgm
Smushed ones are recent I lowered the z offset even more. My initial trace line was pretty pancaked. The higher one is when I had what I thought was the correct setting . (Obviously the "higher" one is further a long in the print) I am recalibrating now and setting an initial higher Z and I will get pictures but the outcome is fairly the same.
It's a pity you fitted a non-standard extruder before getting the machine going ... does anyone here have experience with Bondtech on Mini?
At what temperature are you printing?
Your first layer Z does seem a little too low but the pictures aren't quite sharp enough to be sure, please show the whole of the calibration print. At the end of the calibration you are aiming to print a single layer *sheet*. It should be possible to peel it off in one and fold it without the threads seperating. If it breaks into lines it is too high, not squished enough. If it is a single sheet but with wavy lines or drag marks on it you are too low.
You say you have a dryer, try a longer drying session; it's not your main issue but it might be contributing.
Cheerio,
RE: PETG , Print starts to go bad after a few layers.
I have Bondtech extruder on Mini, and it's a Godsend -no problems here whatsoever.
From what I can see on photos, it looks like you have underextrusion. Did you change E-steps on Mini?
You say you have dehydrator.. what model is it? How long did you dry filament and at what temperature? I ask, because I think your filament isn't dry enough.
[Mini+] [MK3S+BEAR]
RE: PETG , Print starts to go bad after a few layers.
Hi, I check its still at 415 (per bondtechs instructions) . I have a single spool sunlu. I just put it in at 50. I will try to print again this evening unless you think i should go for 24 hours or something.
RE: PETG , Print starts to go bad after a few layers.
We should keep in mind, that there can also be something wrong in hotend (partial clog maybe). But before taking hotend apart, we need to be sure that we are actually using dry filament.
First is needed to be said, that Sunlu dryer (and similar 50€ products) is not meant to dry PETG. This dryer can only keep (already dry) filament dry while printing. The thing is, even if you set temperature to 55°C, actual temperature inside box will go only up to 43°C (at normal room temperature) -and that's not enough for PETG. Maybe different Sunlu models exist, but the one I know doesn't even have a fan inside.
You can't do single 24h drying process with this dryer, because timer allows max 6h. And if temperature drops between drying sessions, filament will accumulate moisture again -that's because moisture remains inside box (condensed on inside walls), because it has no escape.
Speaking for me, this (and similar) dryer is useless. To successfully dry filament, get some cheap food dehydrator.
[Mini+] [MK3S+BEAR]
RE: PETG , Print starts to go bad after a few layers.
So I have been messing with it today quite a bit. Now my zoffset is 1.950 after adjusting the pinda again (I guess it doesnt matter 0 to 1.999 as long as its laying some fat petg dimes heh) . I think I found my issue, I decided to print something different and started with the smaller pieces for the prusa mini stand. I am stringing like spider man (havent adjusted lift off , wiping etc) but I am not getting that problem anymore. I am assuming the file to create the piece has a bunch of settings in it which are not ideal for the mini / petg etc. I have also turned my sunlu into a roll warmer so I can have fresh warm biscuits while printing. I did purchase a heat break when I bought the unit and never installed it (Just got the baby beam torque wrench today so I can put it on if I want I guess). Any negatives you think to installing it?
RE: PETG , Print starts to go bad after a few layers.
Did you calculate the esteps after changing the extruder? It may be that the new extruder is extruding more filament or less filaments per step than the original one.