I need some Slasshee magic for creality and petg optimization

[jaysenodell 13]

I mean anyone is free to comment, but let's face it, @Slashee_the_Cow must have 20-30 of these creality printers and she LOOOOOVES to deep dive into optimizing print profiles. 

 

Slashee, I need your assistence in rationalizing print settings for PRTG (Creality brand but same issue with a random spool that I already tossed). Based on previous slashee wisdom I immediately recognized my blobs as "SLOW THE FORK DOWN" and have been able to get solid prints by just tweaking print speed. But with this last one, I'm down to 10mm and that's just stupid for PETG (and I need to print a pile of these things). 

 

The big question is :

Quote

What is a solid starting profile for PETG that doesn't rip the damn booger string off the deck but doesn't take a decade to print? 

 

My failing project is attached. 

----

 

Things I know are right:

* Printer is solid. no issues printing this in PLA at 150+ don't ask, I was just seeing if it would work.

* Bed is clean

* Temps are the same I've been using for this PETG on other projects

 

Thing I know changed

* The other projects are printing as nice now

* OSX and multiple cura versions don't play nicenice so the 5.7 install may be messing up my 5.6 PETG settings?

* It's summer but rel humidity is still 90-98% every day. 

* New noz (same brand but swapped muitiple) and recalibrated after each swap. 

* New octoprint server (moved from pi 3b+ to n95 with way more speed/ram, but coppied all config objects)

 

Refresh on my systems nonsense

* Creality ender 3 S1 Pro, firmware vs 24S1_301_SWV2.0.8.28F4_F401_FDM_LASER (creality stupid name) from their site

* Octoprint 1.10 on Debian 11 (n95, 3.9gHz/8G/256G), Python 3.9.3

* Cura 5.6 on MacBook Air 13 (i5, 1gH/8G/500G) OSX 14

 

0.5_inch_rope_light_clip_04_PETG_Standard_Quality.3mf

Edited May 6 by jaysenodell

[jaysenodell 13]

I don’t like the fact that octoprint just unlock an achievement “must be one of those days” for canceling 10 consecutive prints in a row. 

[GregValiant 1,272]

@jaysenodell I get an error when I try to open that 3mf file in Cura 5.7.1.  MS 3D Builder won't open it either.

[Slashee_the_Cow 295]

I'll second @GregValiant in saying that I get an error while trying to open the file.

11 hours ago, jaysenodell said:

What is a solid starting profile for PETG that doesn't rip the damn booger string off the deck but doesn't take a decade to print? 

• You gotta run the initial layer pretty damn slow (I usually have it set to 15mm/s with 50mm/s travel) but unlike TPU you don't need to run the whole thing slowly (I usually run at 45mm/s with 150mm/s travel).
• Your Z offset needs to be damn near perfect. PETG is some stringy #&%* to deal with, but in a different way to TPU. TPU is pretty much physically impossible to retract sufficiently so almost any travel will leave a string. PETG is stringy in that it always wants to remain a string leading to the nozzle instead of being planted down.
• Also turn the initial layer flow up to 105-110%. You want to make sure there's enough on the bed for it to stay on the bed.
• Trying to print anything too fine (layer height/line width) is a fool's game. You're not going to be extruding enough to get it to stick.

 

10 hours ago, jaysenodell said:

@Slashee_the_Cow must have 20-30 of these creality printers and she LOOOOOVES to deep dive into optimizing print profiles. 

Greg probably has more than me. I've just managed to have more than my fair share of them die under my watch. I refuse to accept responsibility for any of them.

 

10 hours ago, jaysenodell said:

Based on previous slashee wisdom I immediately recognized my blobs as "SLOW THE FORK DOWN" and have been able to get solid prints by just tweaking print speed

"SLOW THE FORK DOWN!!!!" isn't quite as important with PETG as it is with TPU. I'm not sure I've ever needed to slow down to less than 30mm/s (except for one thing which had really intricate details, which I ran at 20mm/s, but almost all of my PETG prints are more about utility than looks), but it never hurts to make sure your acceleration and jerk aren't too high.

 

10 hours ago, jaysenodell said:

* Temps are the same I've been using for this PETG on other projects

What temp is that? Sometimes for different things you need different temperatures to get the best of them. Usually I run PETG at 245° with the bed at 80°.

 

11 hours ago, jaysenodell said:

* It's summer but rel humidity is still 90-98% every day. 

I hope you're keeping your filament dry. I'm in Australia so I can beat you for relative humidity (hit 100% plenty of times last summer!). But that's the sort of weather where I leave my filament in the dryer (turned on) while printing - it has holes so you can feed filament out, I use some Bowden tubing to get the filament into the tent (because I don't fancy running unprotected filament through a velcro flap, plus I made a holder that goes on the top bar of the printer to hold several Bowden tubes in place and a few spool holders nearby with more tubing, helps for multicolour printing). But in that weather even if I printed yesterday I'll run it in the dryer for an hour or two before printing.

 

11 hours ago, jaysenodell said:

* OSX and multiple cura versions don't play nicenice so the 5.7 install may be messing up my 5.6 PETG settings?

Possible, but if everything else is printing fine I wouldn't think so.

 

So umm... post a valid project file and I can have a look at it more specifically.

[jaysenodell 13]

2 hours ago, GregValiant said:

@jaysenodell I get an error when I try to open that 3mf file in Cura 5.7.1.  MS 3D Builder won't open it either.

It’s a thingiverse STL and shows no errors in 5.6. I forget the thing id and I’m not at my system right now.  I’ll check it again in the morning though. 

[jaysenodell 13]

3 minutes ago, Slashee_the_Cow said:

So umm... post a valid project file and I can have a look at it more specifically.

Not at the he system to validate, but that is a 5.6 project that was used to load several times. If there’s errors mesh tools isn’t complaining very well anymore. I’ll have to try opening it in 5.7 tomorrow as well. 

[Slashee_the_Cow 295]

2 minutes ago, jaysenodell said:

Not at the he system to validate, but that is a 5.6 project that was used to load several times. If there’s errors mesh tools isn’t complaining very well anymore. I’ll have to try opening it in 5.7 tomorrow as well. 

The problem isn't the model in the file. The 3mf file itself is corrupt. Try saving it from Cura again.

[jaysenodell 13]

I've replaced the corrupted file with the file that works. 

[jaysenodell 13]

12 hours ago, Slashee_the_Cow said:

Also turn the initial layer flow up to 105-110%. You want to make sure there's enough on the bed for it to stay on the bed.

 

12 hours ago, Slashee_the_Cow said:

What temp is that? Sometimes for different things you need different temperatures to get the best of them. Usually I run PETG at 245° with the bed at 80°.

So I looked back at my notes and my files. From that we can make the following conclusions:

1. You are consistent in this advice.

2. I saw this advise and noted it.

3. I am a forking morning as i didn't follow it IN MY PROFILES.

 

I have no idea how I have managed to get PETG to work prior to this. I'm going with dumb luck. As you can see from the project I attached, the temps and flow are low EVEN THOUGH I HAVE A NOTE TO SET THEM AT THE VALUES YOU PROVDED HERE. A new run with your values and ... oh look at the pretty Yellow PETG object on my build plate!

 

Forking moron living between my ears. 

 

I'm going to make an attempt to SAVE THE DAMN PETG DEFAULTS THIS TIME and see if I can stop asking the same questions repeatedly.. 

 

Now... while I'm marking this solved by the temp and line adjusts, and I did change my speeds to match yours, When will you be providing "slashee optimized profiles" for starting points for us noobs? Yes yes yes... they will need tweeked for machines and jobs, but clearly I failed at builging my own from scratch. 

[Slashee_the_Cow 295]

Okay you posted that last one while I was still writing this so I reserve the right to finish it:

 

Time for another Big Bulleted List™

• I appreciate the thought about going slow but there's such a thing as too slow and this falls into that category. As I said, I tend to print PETG at 30-45mm/s. It's generally only TPU I have to run at a complete snail's pace.
• You actually have the initial layer speed set higher than the rest of the print.
• 😟
  
  You're not working with shiny PLA here. PETG likes things toasty. As in, I usually print at 245° with the bed at 80° toasty.
• Most filament manufacturers have the recommended print settings (or at least temperature) on the side of the spool somewhere and I wish I didn't have to keep telling people to read them:
  
• Unless for some reason it didn't transfer in the project file, I would say temperature is almost certainly your problem here.
• To back up my speed comment from earlier, on these overhangs you're likely to have a problem running too slow because PETG doesn't really hold its shape until it fully dries:
  
  (Also whoever posted this on Thingiverse really needs to increase their circle segments)
• These bits Cura thinks might need support might present problems, but with the number of walls and skin layers you have they also might not:
  
• Printing it on its arse is an option that almost completely gets rid of any support issues but you'd end up in string city as it gets higher:
  
  PETG is a lot better more annoying at leaving strings than PLA, but it's not nearly as bad as TPU is, especially since cleaning up the strings is only a teeny bit harder than PLA - there's just more of them.
• You have build plate adhesion turned off completely - if you at least do a skirt then it's a much shorter distance from the last point where it's fixed down (end of skirt vs end of nose wipe) to your starting point (less likely to remain a giant string).
• Inside a small object like this, as infill it's much better to use a pattern which has lines closer together at the same density (to test, leave the infill density value the same and go through the different patterns, and look at the infill line distance setting change). This is far too small for something like Cubic to add much strength (because there's nowhere near enough room to create cubes) but who doesn't like some nice Gyroid? Close together and doesn't require many travels:
  

This isn't the biggest bulleted list I've done. That's what we call progress 😉

[jaysenodell 13]

So two points (because I have a few seconds to reply)

• Orientation is to minimize potenital for layer separation as force is applied in the "arms" and to reduce the need for support. 
• The infil is just "there" becuse I didn't set it to "off". This thing just hold the rop light onto a ... thing (in this case dock rail). The only strength should be avoiding the sag of gravity on one side of the prong thingies. That said... i should play with patterns. not sure it matters unless I'm using translucent media though. 

[Slashee_the_Cow 295]

5 hours ago, jaysenodell said:

The infil is just "there" becuse I didn't set it to "off". This thing just hold the rop light onto a ... thing (in this case dock rail). The only strength should be avoiding the sag of gravity on one side of the prong thingies. That said... i should play with patterns. not sure it matters unless I'm using translucent media though. 

Completely empty areas are bad, both in the printing process (higher potential of air bubbles) and for the resilience of the final print. I know you're printing PETG presumably so the whole point is that it's a little flexible, but there needs to be something in there to flex, if your print isn't thin enough that it's entirely walls/shell (and I wouldn't fill this thing with walls or it'll be too solid to bend). Otherwise all the force will be applied to the outer corners and since they hold the shape they can't bend that much before they'll snap.

 

I have several broken PETG prototypes laying around (I can't bear to throw stuff away, it's an actual problem) that can attest to this.