1 Topic by 3d-oodler (edited by 3d-oodler 2013-04-16 05:27:22)

  • 3d-oodler
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Topic: Prints not the same since clog was cleared

Solved: I believe the culprit here was a change in the temperatures measured by the thermistor.  I took my temp from 180C down to 145C and things are a lot better.  I did not know about the low extruder temp reads on the Solidoodle and now I can see why the clog occured running @ 180C.  Most likely my temp reads were changed when I removed and retaped the thermistor in the process of clearning the clog, amplifying the problem. 

Tip: Sending code M302 to override cold extrusion prevention is a quick way to see the impact before you update the firmware with a lower min temp.

Long story short:

1) I got a clog in the middle of a print (PLA @ 180C).
2) I cleared the clog and re-calibrated (extruder steps, slic3r multiplier, Autotune PID)
3) Prints are noticeably worse than before

In the first photo, the left object is the print that clogged in the middle, the right object is the previous finished print, and the one in the middle is about the tenth attempt to tune after the clog was cleared (it's much better than the first few attempts)

http://www.soliforum.com/misc.php?action=pun_attachment&item=1766

The second photo shows that the infill is mis-aligned, while the perimeter lays are not as neat as before, they are not as bad as the infill.

http://www.soliforum.com/misc.php?action=pun_attachment&item=1767

It seems odd to me that I would get a clog in the middle of a print, and at 180C.  This was after printing a few different objects, maybe 3 hours printing time total, which makes me think it may be more symptomatic of another problem.

I intend on checking the stepper motor voltages per:
http://www.solidoodle.com/how-to-2/troubleshooting/

Any other pointers?

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2 Reply by elmoret

  • elmoret
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Re: Prints not the same since clog was cleared

Looks to me like the clog isn't cleared yet.

Filastruder - the robust, inexpensive filament extruder
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3 Reply by 3d-oodler

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Re: Prints not the same since clog was cleared

> Looks to me like the clog isn't cleared yet.

Well, I didn't have any M6 nuts to attach to the barrel to remove the nozzle so I can't be sure I got it all.  However I first submerged the barrel/nozzle in boiling water and used a drill to clear it.  (I had to disassemble the extruder to remove the hot end as plastic had melted north of the PEEK up into the acrylic, pinning it from moving forward)

Then I tried printing, which worked but much worse than the pics showed.

Next, I removed the hot end and heated the heatcore/barrel/nozzle upside down and used a guitar string to push out the plastic from the top, which seemed to do the trick.

When I tell the extruder to dump 70mm quickly in a fixed location, it seems to function the same as before the clog.

Prior to the clog I was running the multiplier at 1.  The after-clog pic has the multiplier at .75, which may explain why the infill in the after pic shows thinner walls (part of my effort to improve things; the result of flow calibration).