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mulder
(@mulder)
Active Member
Purge Tower tuning

I am running a nozzle 0.6 and running into some issues.

Attached is the result of the print - you can see object is great but purge is not so great.

What I am wondering is if I can tune the purge block like I tune the print - spacing line width etc.

What I think is happening is that it assumes 0.4 is nozzle size and when it comes to the purge block it does not push enough filament out and blobs and strings.

From what I can tell it uses the printer settings Extruder X Nozzle diameter to adjust the width of the line.

So if I set to 0.5 and slice the object the width is 0.667 with a max of 0.750

If I set to 0.45 and slice the object the width is 0.600 and max of 0.675

But the lines are so close together that it scrapes and blobs.

If I go with smaller size nozzle then it does not push enough filament and blobs.

So can I fine tune more than what is in Wipe tower or do I need to switch to 0.4 nozzle for MMU2S?

Attachment removed
Posted : 10/07/2019 4:56 pm
gnat
 gnat
(@gnat)
Noble Member
RE: Purge Tower tuning

Beyond the placement and purging volumes, no.

There isn't a supported profile for a 0.6 nozzle, what exactly have you done to use the nozzle?

I haven't played with different nozzles, but I built a 0.05mm layer height profile. All it really came down to was copying the existing profile and removing the bit that kept it from showing up as an option.

The tools I used to help can be found here, but they aren't really ready for prime time use yet. If you aren't at least passingly familiar with Python and poking around your file system then they probably won't do you much good. Basically the tools help you better see what is in the default configurations so you can compare profiles (say the MMU2S profile against the MMU2S Single to see the differences and then the MMU2S Single against the MMU2S Single 0.6 to see those differences) and see how you might build a new one.

MMU tips and troubleshooting
Posted : 10/07/2019 6:54 pm
mulder
(@mulder)
Active Member
Topic starter answered:
RE: Purge Tower tuning

I selected it from menu

Attachment removed
Posted : 10/07/2019 7:07 pm
gnat liked
gnat
 gnat
(@gnat)
Noble Member
RE: Purge Tower tuning

Oh. I don't recall those being options when I ran the wizard and haven't had a need to go back since. Learn something new every day! Not much interested in 0.6 myself, but I want that 0.25 nozzle profile so I guess I need to re-run the wizard...

I have no idea for you then, sorry. I was assuming you tweaked some things yourself and maybe there were other settings that needed to change. The profile coming from Prusa however...

What I see in the purge tower is that as far as the lines go that is similar to what I see with my 0.4 nozzle. Some areas are better overlapping than others and some areas (where it is doing the final retraction before the tool change and then starting the initial purge) will get skipped. I take that as "normal" as it doesn't seem to cause or be related to any issues.

Where I see issues with the tower is on the second(?) layer with the red filament. It's like it doesn't want to stick to itself or (even more so) the blue. Is there anything special about the filament (e.g. mix of types (PLA/PET/ABS/etc), different brands, etc..)?

How does it print in single mode with that nozzle size with those filaments at the same temps? For PLA it wants to print a bit cooler than in single mode. Maybe your filaments don't like the cooler temp?

If I'm correct about about that being the second layer, maybe the blobbing is related to the part fan coming on?

Try moving the tower to a different location on the plate and see if that changes anything. Maybe your bed isn't level?

I assume that you've done Live Z adjustments for the 0.6 nozzle? The brim of the tower looks mostly good, but there are some areas around the lower left corner that look like they could be a shade off.

MMU tips and troubleshooting
Posted : 10/07/2019 7:33 pm
gnat
 gnat
(@gnat)
Noble Member
RE: Purge Tower tuning

Here are the bottom and top of a tower from a 10 hour print. Other than size it looks similar to yours until it goes pear shaped on your second layer.

MMU tips and troubleshooting
Posted : 10/07/2019 7:39 pm
mulder
(@mulder)
Active Member
Topic starter answered:
RE: Purge Tower tuning

Good point - I just got the filament PETG PolyMaker and all are same brand - have not tried single mode yet.

Yes you can see the start of the second layer first brim was green second was red.

As for the fan I think it was off for first three layers but will check on that as well as single mode - I may just put the 0.4 in and see results.

Posted : 10/07/2019 7:51 pm
mulder
(@mulder)
Active Member
Topic starter answered:
RE: Purge Tower tuning

Yes fan was disabled for first 3 layers so not on yet

Posted : 10/07/2019 8:01 pm
gnat
 gnat
(@gnat)
Noble Member
RE: Purge Tower tuning

How about temp changes? I'd have to pull it up, but as I recall the Prusament PETG profile started with one nozzle temp and then changed it after (I think) the second layer. That was one of the things I had to change to use Amazon's PETG (as well as drop the temp).

It is possible that you still have these issues after applying whatever you learn from a single print. In that case you might start by upping the Purge Volume and see if that helps.

MMU tips and troubleshooting
Posted : 10/07/2019 8:19 pm
mulder
(@mulder)
Active Member
Topic starter answered:
RE: Purge Tower tuning

Well it seems I am having the same issue with 0.4 nozzle so size does not matter at this point.

Attachment removed
Posted : 10/07/2019 10:30 pm
mulder
(@mulder)
Active Member
Topic starter answered:
RE: Purge Tower tuning

Well it seems I am having the same issue with 0.4 nozzle so size does not matter at this point.

Attachment removed
Posted : 10/07/2019 10:30 pm
ad.lamy
(@ad-lamy)
Estimable Member
RE: Purge Tower tuning

Personally,  to get a clean purge tower with PETG I change some settings in Prusa Slicer.

In printer settings>Single extruder MM setup, I set extra loading distance to -18, -25 by default

In filament settings>advanced>Ramming settings, tweaked also ramming time to 4, ramming line width to 120, ramming line spacing to 100.

It,s working fine for me since a while.

Attachment removed

MK4/MMU3 - VORON 2.4 350 Stealthburner

Posted : 11/07/2019 5:05 am
mulder
(@mulder)
Active Member
Topic starter answered:
RE: Purge Tower tuning

Ok going to modify these settings and give it a try - will post after test - thanks!

Posted : 11/07/2019 6:57 pm
mulder
(@mulder)
Active Member
Topic starter answered:
RE: Purge Tower tuning

Well that was a huge improvement - I had some stringing on filament which jammed when trying to load the second layer but I will adjust more settings to fix that.

This is looking good thanks for the advice.

Attachment removed
Posted : 11/07/2019 11:43 pm
mulder
(@mulder)
Active Member
Topic starter answered:
RE: Purge Tower tuning

Well that was a huge improvement - I had some stringing on filament which jammed when trying to load the second layer but I will adjust more settings to fix that.

This is looking good thanks for the advice.

Attachment removed
Posted : 11/07/2019 11:43 pm
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