3DPrinting

Hexagonal designs are so pointlessly and hard to print

Seems like everyone shouts dry your filament when they have no clue whats going on. This is just a very hard print with a not perfectly calibrated printer. Has nothing to do with filament humidity. Nothing at all. Calibrate & fine tune the printer. The printing communities feedback/advice is getting progressively worse while printing gets more accessible year for year.

Late to the party, but...

How well tuned is your printer? This whole print is a torture test with lots of retractions and thin walls. For things to go well you will have needed to dial in flow rate, print temperature, cooling, and retraction. As someone else said, if the nozzle catches on an unsupported lever arm (aka one of the vertical pieces before a horizontal bridge has been completed) it can/will break it off.

If your printer has never pulled off this type of print before I suggest running through some basic tuning tests before worrying about potentially wet filament unless you live in a very humid environment. I live in a temperate climate where it doesn't generally get that humid. My printer and filament live in my basement, which has a dehumidifier in it. I've never dried a role of filament and I leave spools unfinished for 6+ months. That's not to say that you never should dry your filament or that doing so won't improve print quality. I'm just trying to say that I have not experienced a higher rate of print failure with older spools.

Thanks again for the valuable feedback! I printed it again with higher temperature, 240. It didn't change much, overall. Same print errors remained, however I got a few less of broken hexagons, so overall the print feels more sturdy.

Looks like the majority opinion here is to blame that all on wet filament. I don't have the right equipment to dry it, so I'd probably just avoid printing similar parts with this spool, and take more precautions when it will be time for a next one. My drybox spool holder build is almost ready.

Looks like a filament moisture issue to me. PETG can get real weird unless it’s really dry. Temp is also a little low, but drying the filament will also fix the stringing issues you were seeing at 240

It looks to me that more is going on here than just how dry the filament is. I see a lot of deformity on the underside of overhang structures which makes me think that the temp is actually too high for the speed that your printing at. I would guess as the plastic went down it was curling edges upwards into the height of the next layer and eventually the nozzle hit this plastic that was too high causing some damage. What speed are you printing at ? Petg likes to print real slow in my experience. Like 20mm/s or less gives it more time to cool. I go as slow as 5-10mm/s when I'm using a large nozzle, but with a .04 you can go faster. Lowering the nozzle temp will reduce the puddling and curling up effect.

I don't dry filaments because I don't care that much about things being perfect. If my plastic is going down goopy, I just turn down the nozzle temp until it isn't... I've come to accept that things often print better if I set the print speeds to be slow. It gives the layers more time to cool before the nozzle comes back around.

HUMIDITY

My guess is mechanical stress during the print.

Think of your print object as a lever. The attachment to the print bed is the fulcrum. The taller the object gets, the longer the lever arm and the more potential for movement, especially while the plastic is still warm and soft.

On the other end of the lever is the nozzle spitting out melted plastic. The melted plastic is sticky (PETG in particular is kind of like chewing gum at print temperature). As the nozzle moves across the printed surface, the sticky plastic pulls on the previous layer, exerting a lateral force (you can watch this happen during the print, it's most obvious with tall thin parts). If there isn't enough contact area between the topmost layer and the one below it (which in your case it appears those parts of the hexagons have very little contact with the layer below) then the top layer can be ripped off.

Basically the individual limbs of the hexagons are too thin, and the angles are too steep. As the print gets taller the whole thing will flex more, making failures more likely near the top.

How long has your filament been exposed to air? It looks like blobby wet filament to me.