Is my nozzle partially clogged?

[darkstarone]

Hi all,

I purchased a Makergear M2 Rev E. w/v4 single extruder a couple of weeks ago and am still getting a feel for things. I am experimenting with the eSun PETG Solid White filament, but seem to be having some strange extrusion issues. Some lines of the print go down perfectly while others appear too thin and have gaps. When this happens they also appear to have a thin line going down the middle of the width of the line.

What I have done:
- Calibrate extrusion multiplier per the forum post. Wall thickness measures exactly within +/-0.01mm
- Leveled my bed several times and print heights are measuring exactly.

What I have not done:
- Did not run cleaning filament through after switching from PLA to ABS then to PETG. I am guilty of being excited to try new filaments and not fully reading the documentation in regards to switching.
- Have not tried taking apart the extrusion assembly to clean the nozzle. Wasn't sure if this was necessary yet.

Print settings:
- eSun solid white PETG filament
- 250C first layer, 242C after - no fan
- 80C bed on factory tape side - no adhesion issues at all
- Extrusion width 0.45
- Extrusion multiplier 0.79
- Nozzle diameter 0.35

Please see the attached pictures.

Thank you

[sthone]

This might help.

[darkstarone]

This might help.

Thanks,

Yes that is a good resource and I have been experimenting with those values. I am down to 50mm/s for default overall printing speed at this point, but solid infill speed is at 80% of that. I will try slowing it down even more. I feel that the outline overlap is perfect where I have set it at this point though, as it begins to glob up on the edges if I set it any higher than 20%. But this is probably also subject to speed.

[Jules]

Wow, fantastic problem description! (That one ought to win an award....seriously!) Pictures are good too.

With the exception of running various filaments through an uncleaned nozzle, you did everything exactly right. You've got the starting height set correctly and the extrusion multiplier calculated and measured, so it really does narrow down the potential problem areas.

It generally takes a while to get a nozzle clogged from buildup though, so probably not an issue just yet. (If you keep doing it, it will be. Good idea to buy a spare nozzle or two to have on hand - just the nozzles, not the hot ends.)

White filament is a category all it's own.....everyone has problems with it to begin with. It has it's own strange set of requirements (I think it's the colorant that they use in it, or the fact that white reflects heat.) You might want to increase the printing temperature by a few degrees - print the whole thing at 247°. It just helps it to melt better and flow a bit better.


Things to check:

1. Make sure you have at least 10-15% Outline Overlap on your Infill tab. Looks a bit lean on the overlap.
2. You can also increase the infill Extrusion Width by about 5% at a time to see if it fills in a little bit better. (Also on the Infill tab in S3D.)
3. Check the tension on the Filament Drive Screw to make sure that you have it set correctly for PETG...use the link below. PETG is a flexible filament and it needs a little more tension than PLA and ABS in order to feed correctly. The write-up below describes how you can check to make sure it is right, no matter what the filament is.

viewtopic.php?f=3&t=3666

4. Speed needs to be kind of slow - about 3200 mm/min

That's actually not a bad print - you just need to fine tune a few settings.

[darkstarone]

Thanks for the replies. I will calibrate the tension on the filament drive and also try the other various tips later today after work.

Thank you

[darkstarone]

I made some adjustments to the Extrusion width, upped by 5% to 105%. Upped Outline overlap to 25% (up 5% from 20)

I have not checked the tension just yet as I was curious to see if these settings would work on a first layer test run, and the attached pictures are the result. Not perfect but much better. I will calibrate the tension tonight and maybe lower the other values just a tad.

Thanks again

[darkstarone]

So after applying the tweaks I mentioned previously and adjusting the tightness of the feeder by about a quarter turn, my results are much better. There are still sometimes a few lines after 5-6 flat ones that have small gaps in them, it seems to have a pattern to it but on some top layers it doesn't happen. It's probably not significant enough to matter overall I suppose.

While print quality is looking really good, I have another major issue, large brown marks at random throughout the print. I have spent a significant amount of time applying tweaks from the PETG guides here on the forums but it seems almost impossible to avoid if you leave a print unattended and aren't around to pick globs off the nozzle.

I have vertical lift enabled which helps a ton, and coast/wipe setting which also help a lot. But it still seems impossible to get rid of. I've tried lowering temps to counteract it, but this PETG needs to be where it's at to avoid other issues. This strategy has worked for me in the past to pretty much eliminate brown spots from white ABS.

This makes printing professional looking parts very difficult. Any tips for avoiding this?

[Jules]

There are still sometimes a few lines after 5-6 flat ones that have small gaps in them, it seems to have a pattern to it but on some top layers it doesn't happen.

Forgot to ask.....do you watch the print closely for the first couple of layers to see if you can pinpoint anything happening mechanically where that thinned area is occurring? (We usually watch how the first couple of layers go down, and if those are good, generally it cuts way down on the problems later in the print.)

The charred bits are the bane of PETG, and unfortunately, they're very visible on white prints. It's just a function of the filament. Those tiny sticky thread-like bits get stuck on the nozzle, and when enough of them build up, they get deposited on the print.

The only thing that (slightly) works in S3D is checking a selection on the Movement Behavior on the Advanced Tab: Avoid Crossing Outline for Travel Behavior. Doesn't get rid of all of them, but it mainly drops them in the Infill areas. (And adds considerable time to the print.)

You can try increasing the retraction a little bit too.....sometimes that helps.

[darkstarone]

I do watch the printer, but I don't really see anything weird happening. Another thing I did notice though, is that when I am printing infill at the +45 degree angle, the gaps are almost always present. While printing the infill at the other angle, -45 degrees, the layers are perfect and smooth and flat.

I was printing ABS before, and didn't have any of these issues occurring in either direction, but I'm not sure if that is proof enough of a hardware issue not existing. I guess I will just avoid the white stuff if possible and use the darker colors I have.

I re leveled my bed and adjusted the z-height (again) just to be sure, and my Z height is measuring perfectly height wise and measurements are nearly perfect on width. I reverted back to a 0.40 extrusion width and have re calibrated accordingly to try and perhaps put another spin on the issues, but now I am even having first layer issues with line gaps. I don't understand why I get gaps in between my lines with calibration number adding up perfectly. I've tried other various things suggested but nothing really seems to work. Increasing first layer width only seems to make the actual gap in between the lines larger, not the actual width being extruded.

0.45 seemed to close those gaps up on the first layer previously, which was originally my reason for selecting that width. My understanding of extrusion multiplier vs resolution isn't very good. I am attempting to print these parts at 0.1mm if that matters.

[darkstarone]

Oh, and I forgot to mention I had some questions regarding the Z offset and the Rev E. printers.

I have seen it said that adjusting the z-offset in simplify does nothing on the Rev E., but I have experimented with it and it seems to work for me?

Can someone explain the exact different with the z height mechanism and firmware compensation on the Rev E. machines?

I know that apparently it should hold the exact 0 position no matter the temperature of the glass. So what is the correct way to troubleshoot Z offset. Set it with the makergear app, setting it in S3D, both? I have also seen conflicting information on whether or not measuring z height of a print is a validation of a correct z gap on the Rev E., is there truth to this?

Thanks and sorry for dropping the bomb with all these questions at once, just trying to make sure I have my facts straight before I go messing with more settings.