Print issue

[jens55]

@deckingman, I have the intention of printing out test objects for temperature and cooling. I need to read up on firmware retraction - I have only ever used the Cura slicer settings so I don't yet know what is involved in setting up for this different mode. I can certainly see how 'on the fly' settings can greatly speed up finding the right settings.
Thanks

The latest test print came out much better than before but can still use further improvement. I have increased the extruder current to maximum but I think that determining proper print temperature should be my next goal. It could be that 135C, my current print temperature, is too cold causing the extruder to work too hard.

The vertical print artifacts are virtually gone even though I have not tuned the belt tension yet. I have ringing of course but that is an entirely new aspect that I need to learn about.

Who knows, maybe one of these days I will get to print an object that is useful. It would be an interesting turn of events

[Norder]

@deckingman The settings of other users are to be understood as guidelines to get to the ideal values ​​for your own printer more quickly.
Therefore it is not irrelevant what other users have for settings.
You are guaranteed to use the settings of other users to get to your goal faster, right ?

@jens55
I use 35mm/s as retract speed (PLA, PETG, ABS und Nylon).

60mm/s sounds better, but can lead to problems because the viscous filament cannot retract properly in this very short time of retraction and further printing and the effect could therefore be reduced.
10mm/s would be too slow (TPU excluded) and would rather slow down the overall print.

35mm/s works very well with most printers.
With TPU, these values ​​will probably not work, since these values ​​are much lower and with very soft TPU you should not pull back completely.

But each filament has its own settings. It may even be that PETG from company A needs different settings than PETG from company B. The differences for the same type of plastic are then more likely to be found in the temperatures than in the length or speed of the retraction.

Regarding the extruder motor...
Watch the temperature of the motor as you change the mA numbers.
My guideline is 50°C to a maximum of 60°C, in which the motors may heat up after a long press (without housing).
If they got too hot, I reduced the mA again.

The motors can withstand higher temperatures without damage, but they should not be overused.
If they get too hot, the mA is too high, the printing speed is too high in the long run or something is running too hard because of dry or jammed bearings, etc.

They must be running well, not skipping steps, and not doing the work normally intended for a more powerful engine.
In the end, my guide value is the temperature after a long press.

Google Translate
-- Original Text --

@deckingman Die Einstellungen anderer User sind als Richtwerte zu verstehen um schneller an die idealen Werte für den eigenen Drucker zu kommen.
Daher ist es nicht irrelevant was andere User für Einstellungen haben.
Du hast Dich garantiert auch an den Einstellungen anderer User orientiert um schneller an Dein Ziel zu gelangen, oder ?

@jens55
Ich nutze 35mm/s als Rückzugsgeschwindigkeit (PLA, PETG, ABS und Nylon).

60mm/s hört sich besser an, kann aber zu Problemen führen weil sich das zähflüssige Filament in dieser sehr kurzen Zeit eines Rückzugs und Weiterdruckens gar nicht richtig zurückziehen kann und somit der Effekt gemindert sein könnte.
10mm/s wäre zu langsam (TPU ausgenommen) und würde eher den gesamten Druck verlangsamen.

35mm/s funktioniert bei den meisten Druckern sehr gut.
Bei TPU werden diese Werte wohl nicht funktionieren, da sind diese Werte viel geringer und bei sehr weichem TPU sollte man gegebenenfalls auf den Rückzug komplett verzichten.

Aber jedes Filament hat da seine eigenen Einstellungen. Es kann sogar sein das PETG von Firma A andere Einstellungen braucht wie PETG von Firma B. Die Unterschiede bei gleicher Kunstoffart sind dann aber eher bei den Temperaturen als bei der Länge oder Geschwindigkeit des Rückzugs zu finden.

Zum Thema Extruder-Motor...
Beobachte die Temperatur des Motors wenn Du die mA Zahlen änderst.
Mein Richtwert ist 50°C bis maximal 60°C in denen sich die Motoren nach einem langen Druck erhitzen dürfen (Ohne Umhausung).
Wurden sie zu heiß, dann habe ich die mA wieder reduziert.

Die Motoren können höhere Temperaturen schadlos überstehen, aber man sollte sie nicht überstrapazieren.
Werden sie zu heiß, ist die mA zu hoch, die Druckgeschwindigkeit auf dauer zu hoch oder etwas läuft zu schwer wegen trockener oder verklemter Lager etc pp.

Sie müssen gut laufen, dürfen keine Schritte auslassen und sollten nicht die Arbeit verrichten die normalerweise für einen stärkerer Motor gedacht ist.
Mein Richtwert ist am Ende die Temperatur nach einem langen Druck.

[jens55]

@Norder said in Print issue:

@jens55
I use 35mm/s as retract speed (PLA, PETG, ABS und Nylon).

Yes, you have mentioned that before but you did not mention your setting for the speed you use for un-doing / reversing the retract. I am curious what you use for that setting.

[Norder]

@jens55
At the same speed.

[jens55]

@Norder, thanks!

[Norder]

@jens55
I think I once tested two different speeds with TPU. But then I went back to the same values.

My nozzle is made of tungsten carbide and is coated with ceramic on the inside, so it is very smooth and no filament sticks to it.
Back in the day with the brass jets it was a little harder to find the perfect retract setting. Brass nozzles behave a little more in the direction of a "diva".

[deckingman]

@Norder said in Print issue:

@deckingman The settings of other users are to be understood as guidelines to get to the ideal values ​​for your own printer more quickly.
Therefore it is not irrelevant what other users have for settings.
You are guaranteed to use the settings of other users to get to your goal faster, right ?

If the machines are identical, then possibly. Otherwise, I stand by my comment that the settings that other people use, on different machines, are irrelevant. In fact, I'd go as far as to say that they can be misleading and serve to prevent people from finding the optimum settings for their particular machine. I would say that your advice to the OP about what percentage of part cooling fan speed to use is a case in point. You specifically stated that at 80mm/sec and 240 deg C the part cooling fan speed should be more than 20% for PETG. That sweeping statement completely disregards numerous factors, not least of which is the number and power of any part cooling fans as well as the arrangement of any ducts. That setting might work best for you, but for other machines with unknown numbers of fans of undetermined power, the only true value is somewhere between zero and 100%.

[jens55]

@deckingman, while I agree with your sentiments especially in regards to cooling, I also appreciate the information Norder posted. Cooling is a bit of a red herring because as you say, nobody knows what exactly my situation is. On the other hand, I can infer a starting point if someone tells me they are running 10% or they are running 1000%. While the starting point might be wrong, it gives me more confidence (yes, possibly wrong confidence). In any case, I appreciate both of your inputs !
The issue with 'feed' was mentioned several times in this thread and while not directly pointing to the issue, it got me exploring stuff and helped me find a setup problem that I have not been aware of for at least a year. So while my setup is totally different from other peoples setup, the information given was still valuable for me.
It is always understood that any settings shared are just that, shared settings, that may or may not apply to my specific setup.

Again, thanks to all that chimed in on this thread!!! I have learned from your input!

[Norder]

And that's exactly what it means... these are pure recommendations and values ​​that you can but don't have to follow.

I think we're all grown up and educated enough that I don't have to write every time I give data, so I don't take it over 1:1.
That's what common sense tells you, or am I wrong?
@jens55 at least understood it exactly as it was meant.

To the fans...
If someone writes that they print at 80mm/s and use 20% fans and then I look at the photo of the print result, where my experience tells me that these 20% could probably be too little, then I write it and write how my settings are so that you can orientate yourself on them if you want.
If that is then described as misleading, then what is the point of this forum?

And some components of a printer are not that different, a direct extruder is a direct extruder and 6.5mm retract is simply too much for 99% of the extruder models.

But I am happy that @jens55 understood it correctly and that it helped him further.
Was my intention.

@jens55
How are your print results now?
What have you done so far and what has helped more or less?

Google Translate
-- Original Text --

Und genau so ist es auch gemeint... es sind reine Empfehlungen und Werte an die man sich orientieren kann aber nicht muss.

Ich denke wir sind alle erwachsen und gebildet genug dass ich nicht bei jeder Angabe von Daten dazu schreiben muss, diese nicht 1:1 zu übernehmen.
Das sagt einem doch der gesunde Menschenverstand, oder irre ich mich da ?
@jens55 hat es zumindest genau so verstanden wie es gemeint war.

Zu den Lüftern...
Wenn jemand schreibt dass er mit 80mm/s druckt und dazu 20% Lüfter nutzt und ich mir dann das Foto von dem Druckergebnis ansehe, wo meine Erfahrung mir sagt dass diese 20% vermutlich zu wenig sein könnten, dann schreibe ich es und schreibe dazu wie meine Einstellungen sind, damit man sich daran orientieren kann wenn man möchte.
Wenn dass dann als irreführend bezeichnet wird, ja wozu hat dieses Forum dann noch Sinn ?

Und so verschieden sind manche Bauteile eines Druckers nicht, ein Direkt-Extruder ist ein Direkt-Extruder und da sind 6,5mm Retrakt zu 99% der Extrudermodelle einfach zu viel.

Ich freue mich aber das @jens55 es richtig verstanden hat und es ihm weiter geholfen hat.
War meine Absicht.

@jens55
Wie sind denn jetzt Deine Druckergebnisse ?
Was hast Du bis jetzt gemacht und was hat mehr oder weniger geholfen ?

[jens55]

@Norder said in Print issue:

@jens55
How are your print results now?
What have you done so far and what has helped more or less?

The print results are dramatically better but unfortunately still not what I would call 'good'
I no longer get the two spots where the major under extrusions happened. Even knowing about the under-powered extruder motor, I do not understand what exactly caused the two distinct areas of failure rather than seeing a distributed general under extrusion. I suspect it is based on the sequence of printing actions prior to those two spots since changing the printing actions eliminated the holes.
I also get far less tiny holes in the print but they do still exist. The problem is more acute as the print gets over maybe 15 or more mm tall. I also still get what I would call 'streaking' where individual layers aren't placed exactly over top of each other. I would normally suspect this to be mechanical in nature but this is not an issue when printing with PLA which would indicate print settings.
I have reduced retraction to 2 mm and might try reducing it further. Most of the improvements were the result of increasing extruder power.
I have reduced the vertical printing artifacts to a large degree but because the surface finish is still below par, it is difficult to tell if the issue (vertical marks) has been completely fixed. The issue was strictly mechanical (idlers not running smoothly) as was expected. I still have ringing but have not done anything so far to fix that - it is not an issue of significance until everything else is sorted.
In my digging on the internet, I have come across mention that too large a retraction can in fact cause pock marks. This is something I was not aware of.
My next efforts will be to optimizing retraction and print temperature which hopefully will address some of the remaining issues.
If I didn't have a substantial inventory of petg, I would just stop printing with it but I do have a large pile of spools so I must power through this problem one way or another.
I have had limited time for sorting things out but will be getting back to it shortly.

[jens55]

I swear, I spend more time fixing and adjusting my printers than actually printing stuff.
The one issue that I fixed is the idler that wasn't running entirely smooth. Unfortunately, a ton of other issues cropped up.
The insufficient power to extrude that caused my to increase the motor current .... while the jury is still out on that one, it would appear that it was caused by a bad connection of the motor wiring harness to the board that provides the extruder drive. While I can't be sure, I have verified that the motor was extremely weak, the motor had plenty of power on a different driver board, when I plugged the motor back into the original board, it once again had proper power. The only explanation that I can come up with is that at least one of the contacts had a high resistance. There were several power cycles involved so maybe the electronics needed resetting? I normally don't shut the printer down which causes other funky issues after a few days.
The feed power got noticed because the feed became extremely inconsistent and I spent considerable time trying to find the cause for that. In the process of taking the hot end/extruder apart several times, I found a bit of crap in the Dragon hot end and cleared that out but I have no idea if the recent problems may have caused the crap to get lodged in the hot end. I also cleaned out some crap in the extruder gears. A chunk of filament was hiding behind one of the two feed gears. Again I do not know when this happened or if it is related to the motor issues.
The petg I am using is recommending 230-240C for the hotend temperature. A temperature tower indicated that 235 was not enough. I switched to 250C.
I switched to 3 mm retraction from 6.5 mm
I found out that my 40W hot end heater is insufficient to reach 250C if there is any part cooling at all. I have ordered some 50W heaters.
I will probably need to re-do all my test prints because if the filament feed was poor, the calibration results are suspect.
Sometimes I regret that I started monkeying around with printers. My first printer, a CR-10, seemed to always work .... but then the CR-10 was a lot simpler and maybe I was wearing rose coloured glasses at the time.
Anyway, I thought I would provide an update in case anybody was wondering what the status was.

[mikeabuilder]

@jens55 - Nice summary. I always tell people that aske me about getting their own 3D printer that it's like 100 years ago and being one of the first people to own a car over. You have to be a part-time mechanic to get anywhere. You'll have a hobby for a long as you can stand it.