Lines in prints

[Gramps]

Recently I started noticing these small voids in my prints. I first contributed it to a new filament I was trying. But now I'm seeing them in prints printed with Hatchbox which is my preferred filament. Doesn't necessary happen in the entire print. The tube in the picture was printed standing up. The white or light colored line is from the lighting and not in the print. I'm using Capacon boden tubing on my Ender 3 v2 and have been for a while now. I did do the mod where there is a 33mm piece of capacon tube in the hotend with a washer on top so the tube in trapped between the nozzle and fitting. I'm thinking a retraction issue but not sure if it's to much or not enough or speed.

[Ender5r]

How long has it been since you last changed that short piece of Capricorn? Could the section that's in the hot zone be constricted?

[Alan]

What z-seam settings are you using in Cura? I've seen similar lines (not exclusive to Hatchbox) in cylindrical shape and they went away when I forced the Z-seam alignment to be User Specified and Back (pick any spot).

Cheers

[Ender5r]

Seems like it might be a spot to use "print outside walls first", to maybe help keep the seem on the inside?

[Gramps]

The Capricorn inter tube was replaced maybe a week ago. I use Prusa Slicer using the stock Ender 3 setting for the most part. Haven't made any changes in the slicer. It's not really a seam more like skipping. The other thing I've done recently was replace the hot end fan. The one has more cfm. Here are 2 other prints where the voids are easier to see and bigger than in the above print. These were printed with Overture PLA, I printed a whole spool of it and didn't see the voids until towards the end. The new fan was installed before these were printed.



I think the top one was printed 1st on the 2nd one I turned up the temp 3 degrees.

[roon4660]

I would change the piece of Capricorn tubing. I had to change mine already. I use that same system without the washer which I can never squeeze in and it works fine without.

[Geit]

Could be the retract. It seems to print the cross-pattern fine and then, when starting the walls again there is not enough filament at first. It seems during retract the more solid filament gets separated from the fully melted filament inside the nozzle. This is why the beginning, after retract, works for a few millimetre and then the gap is happening. There was air pushed out of the nozzle, which got in during the retract. Until the air is out and the pressure it normalized again, next to no filament leaves the nozzle.

It also explains why it starts and stops above and below the cross-pattern, as there is no retract.

I would try reducing the retract a little and see what changes.

[Ender5r]

I'm looking forward to seeing how this gets resolved.

[Gramps]

Printed another part for my reel spool, I bumped the temp up 5 degrees to 200 and from what can tell it doesn't have the voids. I'm printing the last piece now and left the temp at 195 so we'll see if what it looks like.

[Gramps]

The part I increased the heat on printed fine. The last part printed fine too. Think I will scale the crate and printed it using Hatchbox and see what happens

[Geit]

More heat means more flow (ooze) and may also compensate retract issues as the hardened filament cannot disconnect from the molten one, like it did before.

[Ender5r]

I also would not read too much into temperatures, retractions, print speed, etc. as far as filaments. Just because a filament prints well at certain settings & another filament doesn't, that does not mean the 2nd filament is somehow defective. I've found that each filament needs its own particular settings to do its best. I create Cura profiles for each filament I have.

[Geit]

I never had any issues with temperature. I always take the middle/upper middle mentioned on the filament.

If there is "180°C to 220°C" on the filament it means you can print at 180°C when you print very slow and for very fast prints you can go up to 220°C. At least this was to my understanding how it works. The hotter the filament the more it tends to string and ooze. Prints peed compensates this because the print speed cools down the hotend faster.

Since around 60mm/s is normal it should be around 50% of that scale, which is 200°C. If you print faster you can increase the temperature to compensate an under powered heater to some extend.

More important is that 220°C is fine and the filament will not turn into dust. There is also a save margin you can over and under run. So printing this PLA with 230°C will probably work as well as at 170°C.

In fact I printed over a year using 235°C. I had issues with the PTFE Pipe in my hotend and the flow got lower and lower. I compensated it by increasing the temperature every time a print failed or looked bad. That way I avoided repairing my printer for more than a year. My usual default for PLA is 215°C.

[Gramps]

I also use different filament profiles in Prusa Slicer for the different filament brands or even the same brand if the filament requires it. Like Geit I pick the middle of the range on the box as a starting point then work from there. The gray I printed the crates with was towards the end of the spool and the rest of the spool printed with out issues. Maybe it's something with the crates. I'm going to print another one using silver Hatchbox. but waiting until I get the new Ezabl installed and dialed in

[Ender5r]

I've begun a routine of printing a temp tower at the start of each spool. Following Geit's comments, I may also look into printing multiple towers, each at a different speed.

[Geit]

Since I basically ended up for using the same filament brand in years, I never printed a temperature tower at all.

In total I used two brands of ABS and two brands of PLA, which in total is actually just three brands I still have my first role of PETG in storage, which I really need to test some tie soon.