Something failed, now prints are far too thin

RigidBot 10x10x10, Repetier with Slic3r

I was printing fine for about a month (with some newbie-related difficulties), and then "something" happened. Every job just started printing far too thinly, things started coming out as a spiderweb that would vaguely resemble my job if I was lucky. Cranking up the extruder rate to ridiculous levels would help slightly but nothing close to a solid object.

I tried everything I could think of. Reinstalling the software, replacing the firmware, setting up a completely new computer to control it, etc. I assume it's mechanical but I'm not sure how. I'm a newbie to 3d printers but have a general understanding of electronics. I've been hesitant to start ripping things apart unguided however in case I make things even worse.

I'm not sure if it's common, or was happening before the issue, but I've noticed bits of PLA 'shavings' on top of where the filament feeds into the extruder. Is that normal, or indicative of too much resistance as it's being pulled in?

I can take a video of it printing later tonight if anybody's willing to help.

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Originally Posted by Wulf

I can take a video of it printing later tonight if anybody's willing to help.

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A couple short videos will get you lots of insight. Most likely, a couple small changes will get you back to where you want to be.

The piece as seen in Repetier-Host:

http://3dprintboard.com/attachment.p...tid=4505&stc=1

The monstrosity as seen in reality:

http://youtu.be/E_BV2iz1Hpk

Any input? Thanks.

Is the video quality good enough to get an idea of what's happening? If anybody has suggestions for a better recording angle let me know.

Firstly, level your bed. It's easy to see that on one side, the first layer isn't sticking as the nozzle is too high, but on the other the filament is being spread too thinly on the bed as the nozzle is too low. Level your bed and get the first layer correct.

Secondly, calibrate your e-steps per mm, as per the reprap wiki calibration guide. http://reprap.org/wiki/Calibration

If you're still having problems after that, come back with another video.

It's definitely due for re-leveling and I'll take care of that right away, but the problem began before it became unlevel. I screwed it up at some point in my attempts to fix it.

Thanks for the response and I'll try get a new video up soon.

Your problem sounds like a clogged nozzle...

I'll try make a video tomorrow, but the bed's been re-leveled. I've discovered my print bed is not level in the process, but I can deal with that another time. As long as I print near the center, it's level.

Extrusion rate seems perfectly calibrated to the best of my detection abilities.

Now the problem seems to be narrowed down (as i see it) to when it's filling in a layer. Perimeters are coming out fine while it traces lines around the edge, but when it fills in the area between perimeters it's too thin. So now I'm getting objects with a fine horizontal shell but with non-solid top layers.

I have encountered this problem before too. The printed results became thinner and it wasn't really good to look at. I read blogs and other forums and through it, I was able to fix up the problem. Fortunately, it's fine now.

Wulf I had your exact same problem. Perimeters seemed to be ok, infill was too thin and couldnt support anything. My problem ended up being my pinchwheel slipping when doing infill and supprots. It could do well with long extrusions like perimeters but infills are a lot of back and forth, pinchwheel couldnt handle it so it slipped a lot and extrusion came out crappy.

That definitely sounds like it would fit what I'm seeing. I took off the fan/heatsink to get a better look at it and the amount of plastic shavings looks like it's slipping and scraping some off pretty regularly.

Did you have to replace the part or is there some sort of software workaround that would treat infill as perimeter?

That's it right there. Plastic shavings means pinchwheel is failing. You need to either get a new pinchwheel or adjust the tension on it, I don't know your specific machine but those are the only two options really. The only thing that worked for me with a worn out pinhwheel was printing very slowly, it can keep up with 15 mm/sec infill, anything above that and it would slip. It's slow, but it least it prints. I bought 2 brand new pinchwheels and I will install one in the next few days. I'll let you know what happens.

Well, on the plus side I've narrowed down the problem, and my printer is printing perfectly again (for some definitions of perfectly).

On the negative side, my magic number is 5 mm/s. Any faster than 5 mm/s and it starts getting stringy...

I look forward to hearing your results after replacing it.

And halfway through a 14 hour print it failed again. Now even 5 mm/s isn't slow enough.

Pulled everything apart and one contributing factor was that the PFE tube had expanded from the heat and was causing far too much friction. Stretched that out a reasonable amount, and while I had it apart the m*f*ing power wire for the fan snapped off. Gonna have to buy a new one and splice it in, since the RigidBot has it hardwired there instead of using a connector....

After that I was attempting to troubleshoot in small bursts to avoid overheating anything, and the temperature kept fluctuating between 190 (where it was set) and (210), so maybe the thermistor is crapping out too. Regardless, the PFE tube hadn't been the only issue, was unable to get a single line to lay down properly after that.

Maybe it all just needs to be tossed in a pile and set ablaze... Or I need a nap.

I suspect that this is slic3r's fault; I just wish I could tell you how to fix it. My printer was able to put out the pre-loaded sample Gcode without any trouble, but as soon as I generated my own with Slic3r my prints came out just like that. As soon as I switched to S3D everything started coming out perfectly. That's not a sales plug, mind you; I'm sure you can get slic3r to serve you just fine.

I'm recognizing a lot of similar issues in your video. For example, the nozzle isn't mashing each layer down onto the previous one; it's depositing the layers from too high, so you're getting an object that looks like it was spun out of filament instead of one that looks like it was carefully formed out of flat layers of material. If you can't find any mechanical issues(though those "shards of PLA sound concerning as well), perhaps you could try running some pre-generated Gcode that was designed for your particular RigidBot? That way you could either pinpoint or eliminate Slic3r as the cause of your problem.

Definitely check to make sure your bore is clean. I had intermittent feed problems that degraded over time, but miraculously recovered after a brief pause in printing. Turned out to be a piece of metallic debris floating in the melt zone, never blocked it but increased back pressure until the hobbed bolt started chewing the filament. Once the filament started getting chewed in one place, it would snowball quickly and the hobbed bolt quickly lost its ability to grip and extrude the filament. Removal of the debris definitively ended that issue.

I am having the same problem, but it seems to be getting worse. The extruded filament is stringy and fails to attach to the plate despite having leveled the plate. The attachment might be connected to the fan, but I dont know what to do with the extruder.

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Originally Posted by DBFIU

Your problem sounds like a clogged nozzle...

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what i was thinking.
Sometimes you can over think these issues.

Buggering around with the in depth printing settings is almost never necessary.
Clean the nozzle or fit a new one. Betch it sorts it :-)