nerys
Posts: 256
Joined: Tue Mar 29, 2016 8:47 pm

Zits? (yes I read the guide :-)

Ok I am getting zits. First let me clarify. these are EXTREMELY minor. SO minor that most of the time I can ignore them as irrelevant.

but on some models or with some filaments they become obnoxious and I would like to eliminate them or at least reduce them.

but ANYTHING and I mean ANYTHING I do 100% of the time makes it worse. every time. no exceptions.

I understand if its at the beginning try extra restart modifications. if its at the end try coast modifications.

problem is EITHER of those always makes it worse no matter how small the tweak. maybe my tweaks are not small enough? ie I am passing the sweet spot and swinging the other way to worse again?

also HOW do I identify whether its at the start or end of a layer? no matter how carefully I watch the print in progress I simply can not determine where its happening (beginning or end) its always a couple layers later I see the zit but its already printed it. (probably because of how small they are. for example this zipper is barely visible. (image attached) enough that I had a tough time capturing it on camera.

Any suggestions on a diagnostics process to fine tune this? its VERY consistent and not random so it should be possible to tune it out or at least reduce it.

random start points is horrible in extreme. it does not retract when doing it with that method so you end up with internal strings and a weak print so I always leave it set to optimize for speed. (it seems the open space inside the model is not considered open space so it does not retract)
Attachments
zipper.JPG
horst.w
Posts: 861
Joined: Fri Oct 17, 2014 5:00 pm

Re: Zits? (yes I read the guide :-)

... I think its first an overextrusion and 2nd a temperatue problem, may be to hot printed or not enough cooling. More issues may be.

The best way is to attache your factory file here.

regards
horst.w, GER
nerys
Posts: 256
Joined: Tue Mar 29, 2016 8:47 pm

Re: Zits? (yes I read the guide :-)

Definately no over extrusion. Calibrated very well super clean prints otherwise. Oozing too much yes

I added -.3 restart and that is compensating a lot for the zits but not the zipper (though inwill have to try that again with the -.3

Now i do run hot 220c seems tonprint the best.

This pla is ..... Unhappy cooler....

I will ppst the factory file when i get home from work tonight.
Dissymmetry
Posts: 3
Joined: Thu May 25, 2017 5:34 pm

Re: Zits? (yes I read the guide :-)

Are you printing over USB? If so, try printing from an SD card if you can. I have found that USB communications occasionally cause short pauses between g-code lines. I always print from SD now since I figured this out. If you use the Machine Control Panel and click the Print from SD Card you can still use most of the controls. My position readout doesn't work any more when I do this, but it's a small price to pay for cleaner prints.
nerys
Posts: 256
Joined: Tue Mar 29, 2016 8:47 pm

Re: Zits? (yes I read the guide :-)

I have never successfully gotten any printer except my maker bot mini (my first printer) to connect over usb to a computer.

so all printing is by memory cards.
Dissymmetry
Posts: 3
Joined: Thu May 25, 2017 5:34 pm

Re: Zits? (yes I read the guide :-)

Even though it's not a highly satisfying solution and may not even be the cause of the problem, ... running the print at 50% speed may make it go away completely.
nerys
Posts: 256
Joined: Tue Mar 29, 2016 8:47 pm

Re: Zits? (yes I read the guide :-)

Sure cant hurt to try. I will run one at 50% and report back.
gearsawe
Posts: 233
Joined: Sun Sep 10, 2017 11:06 pm

Re: Zits? (yes I read the guide :-)

You many never get this to go away completely. even our $200,000 machine has this. This is a seam where the outer perimeter starts and ends for each layer.
The only method which does not have this option is the (vase mode) but this only allow one wall thickness

I have this less with atleast 2 walls and the inside is printed first. And may need a bit more retraction. But you will always have this seam.
nerys
Posts: 256
Joined: Tue Mar 29, 2016 8:47 pm

Re: Zits? (yes I read the guide :-)

What a pity. It really does not detract much i guess its very soft and subtle. Just have to live with it.
Lorcoft
Posts: 22
Joined: Thu Jul 23, 2015 7:19 pm

Re: Zits? (yes I read the guide :-)

I would try setting the printer so that this deformation is in a straight line running up a print. This will let you look at many instances at once. From what I've seen if it's an issue with the beginning of a layer, it will appear to come out of the inside of the print and there will be a very small gap behind it.

If the problem is with the completion of a line, it will appear as a bump that you should see forming as the layer finishes and usually doesn't have a gap, but this isn't always the case.

I played with the settings to minimize it as best I could, then I found a spot on the print where a single line wouldn't be as noticeable; and I set the slicer to start and stop there. It takes a bit of eyeballing with each print in order to optimize, but I've had good success with hiding the line.


cheers;

Lorcoft.

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