Printer no longer extrudes correctly  

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doug.c5
(@doug-c5)
Active Member

I had some wood-infused PLA decide to self-destruct inside my printer. I had to take apart the extruder (following the guide) and push the filament through. The PTFE tube looked OK to me, so I put it back in. (I also changed the hotend from .6 to .4, as I was going back to plain PLA. I did remember to change the setting in the menu).

I re-adjusted the PINDA, and tried to adjust the first layer. But I couldn't get the rectangle at the end to fill in, so I thought maybe there was some gunk left. I did a cold pull, and it looked textbook. But I still can't get a successful run, so I'm thinking that the problem might be elsewhere. I am suspicious that it is not putting out enough filament because the starting extrusion isn't flat, it's curly. And it seemed that the more I tried, the worse it got (see -3, -2, last, which were .055, .127, .025: First tries were 0.0, .043, .078, .1).

I just don't know where to go from here. I've tried several different filaments, by different companies, and these examples are with the filament that came with the unit. I have the filament in dehumidified storage.

The links above are images, but I'll attach one as well.

Thanks!

Best Answer by bobstro:

It looks like you just need to re-calibrate your Live-Z. Perhaps you bumped the bed a bit when dealing with the clog. Not a big deal in any case.

If you have not already done so, try using Jeff Jordan's "Life Adjust" procedure for calibrating your Live-Z setting. It is much easier to use and understand than the on-board routine and much easier to make mid-print adjustments accurately with. In general, start high (less negative) and work lower (more negative) in large increments (e.g. 0.1mm) until the filament starts to stick on its own. When you've got your Live-Z setting adjusted properly, you should be able to gently rub the extruded lines on the PEI surface without dislodging them.  Then start lowering (more negative) the level until there are no gaps between layers. You should not be able to peel the lines apart after printing, but the top should be regular. 
 
Be sure to give the print surface a good clean before calibrating and you should be all set.
Posted : 01/09/2020 7:34 pm
bobstro
(@bobstro)
Illustrious Member

It looks like you just need to re-calibrate your Live-Z. Perhaps you bumped the bed a bit when dealing with the clog. Not a big deal in any case.

If you have not already done so, try using Jeff Jordan's "Life Adjust" procedure for calibrating your Live-Z setting. It is much easier to use and understand than the on-board routine and much easier to make mid-print adjustments accurately with. In general, start high (less negative) and work lower (more negative) in large increments (e.g. 0.1mm) until the filament starts to stick on its own. When you've got your Live-Z setting adjusted properly, you should be able to gently rub the extruded lines on the PEI surface without dislodging them.  Then start lowering (more negative) the level until there are no gaps between layers. You should not be able to peel the lines apart after printing, but the top should be regular. 
 
Be sure to give the print surface a good clean before calibrating and you should be all set.
My notes and disclaimers on 3D printing and miscellaneous other tech projects
He is intelligent, but not experienced. His pattern indicates two dimensional thinking. -- Spock in Star Trek: The Wrath of Khan...
Posted : 01/09/2020 8:13 pm
jsw
 jsw
(@jsw)
Prominent Member

Agree.

Z looks too high, give-away is the lines which are skewed and obviously not adhered to the bed.

I also see some smudges (finger grease?) on your print bed.  Please be sure it's really most sincerely clean.

I'm sold on using any of the common 3x3 Z test prints over the internal routine, and I'll run one as a sanity check every so often.  (photo below)

There's also a thread here on a more detailed bed level measuring and calibration here.

Posted : 01/09/2020 9:01 pm
doug.c5
(@doug-c5)
Active Member

@bobstro

This answer was amazingly helpful! The official instructions on Z axis adjust don't give a suggested increment number anywhere, and since the units on the interface are 0.001, increasing by 0.100 each time seemed incredibly reckless. Thanks for "giving me permission" to "go big".

I still used the built-in routine to dial it in: "Life Adjust" said that it was "only" 12 minutes, and that's way too long for my patience! However, once I thought I got the level set, at 1.0, I ran it, and it was good that I did: When I held it up to the light, I could see that it was a bit thin at spots, and .1 more was better.

It scared the crap out of me, though! It makes this horribly loud klaxon sound a little way in. I was not expecting that!

Posted : 03/09/2020 3:59 am
doug.c5
(@doug-c5)
Active Member

@jsw

Thanks for the help! I gave my bed a good cleaning, and that helped a lot, too!

Posted : 03/09/2020 4:05 am
doug.c5
(@doug-c5)
Active Member

I couldn't figure out how to attach the photos in time, so here they are.

Posted : 03/09/2020 4:07 am
bobstro
(@bobstro)
Illustrious Member

You'll find the "Life Adjust" approach goes quickly after a few times. There's nothing magical about that print, so you can generate squares of any size and thickness. I find I can usually eyeball the final adjustment about 25-50% of the way through a print. I do it when making any hardware changes and whenever adhesion gets flaky, along with a wash. 

My notes and disclaimers on 3D printing and miscellaneous other tech projects
He is intelligent, but not experienced. His pattern indicates two dimensional thinking. -- Spock in Star Trek: The Wrath of Khan...
Posted : 03/09/2020 4:37 am
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