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rshirk001@gmail.com
(@rshirk001gmail-com)
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hotend thermal runaway mid print

i recently swapped out my "E3d Prusa MK3 V6 Hotend" got it from amazon.   before the swap i was intermittently getting globs of plastic on print or burn marks on parts.    after swapping out heat block.   I have noticed that mid print using prusaslicer the temp will suddenly skyrocket till overtemp alarm goes off.    any ideas?  could it be the board?

Thanks

Posted : 21/05/2021 6:43 pm
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(@)
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RE: hotend thermal runaway mid print

No - probably something you did when changing hot ends.  As a data point, the blobs you were getting were also probably an assembly issue - leaks from not having the nozzle and heat break seated properly. 

What is the exact error you are getting now?

Double check all the wires are routed correctly, that the thermistor and heater wires don't bend sharply at the heater block. And check the connections at the Einsy - make sure you didn't accidentally swap the bed and hot end thermistor plugs.

If all the looks good - you might try a PID calibration.

This post was modified 2 months ago by --
Posted : 21/05/2021 9:35 pm
rshirk001@gmail.com
(@rshirk001gmail-com)
New Member
Topic starter answered:
RE: hotend thermal runaway mid print

@tim-2

im not getting an actual error message other than the last time it did it i was in same room with printer and it about 48mm up (Making funnel) and it started beeping going to back corner and temp was at 285c the print job runs at 225c.  i have had the mk3 for about 3 years, with minimal issues. i will recheck wiring again.  when it did it before I reseated the connections on board, updated firmware.

Posted : 21/05/2021 9:50 pm
cwbullet
(@cwbullet)
Illustrious Member
RE: hotend thermal runaway mid print

@rshirk001gmail-com

With what you described, it is likely the wiring.  

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Chuck H
3D Printer Review Blog...
Posted : 21/05/2021 11:08 pm
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RE: hotend thermal runaway mid print

@rshirk001gmail-com

When you saw this happen, what were the two temperatures on the nozzle display? 

 SETPOINT / ACTUAL

If Actual was higher than Setpoint, it's likely the Einsy is failing.

Posted : 21/05/2021 11:39 pm
rshirk001@gmail.com
(@rshirk001gmail-com)
New Member
Topic starter answered:
RE: hotend thermal runaway mid print

@tim-2

setpoint was 225c the actual showed 285 

Posted : 22/05/2021 12:02 am
cwbullet
(@cwbullet)
Illustrious Member
RE: hotend thermal runaway mid print

@rshirk001gmail-com

Yup.  It is either the einsey or you have something wired wrong.  I agree with @tim - this is the einsey.  

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Chuck H
3D Printer Review Blog...
Posted : 22/05/2021 12:10 am
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(@)
Illustrious Member
RE: hotend thermal runaway mid print

The only thing that will cause that is failed code execution (the Einsy locked up or crashed and wasn't operating - which is unlikely because the LCD temp was being updated); a failed thermistor (intermittent) - but the Einsy should have flagged a thermal run away; or a failed heater driver - and I'd expect the Einsy to alarm with a Thermal Runaway error there, too: but maybe I'm expecting too much from it. 

Regardless, you have a fire hazard - us guessing won't solve it for you - get out the meter and start trying to diagnose what is failing.

Heck, you might even have been driving the printer with Octoprint or a PC and the USB crashed. Again - stupid wild ass guesses that could get your house burned down.

Posted : 22/05/2021 12:13 am
rshirk001@gmail.com
(@rshirk001gmail-com)
New Member
Topic starter answered:
RE: hotend thermal runaway mid print

thank you all,

 

I think I will try changing the ensey, I don't use pc or octoprint.   either way i agree , the way it is i dont dare leave it unattended and now its power cord is pulled till i replace a few more things .

Posted : 22/05/2021 12:27 am
cwbullet
(@cwbullet)
Illustrious Member
RE: hotend thermal runaway mid print

@rshirk001gmail-com

Good luck.  

--------------------
Chuck H
3D Printer Review Blog...
Posted : 22/05/2021 12:30 am
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RE: hotend thermal runaway mid print

@rshirk001gmail-com

With a DMM, you can do a few simple tests to confirm a shorted heater driver or basic thermistor state. If things only fail at temp, it'll be a bit harder to diagnose. Shotgun approach (replace parts until it works) may be the quickest way to get running again. But at $100+ for an Einsy ... ouch.

Without a DMM you can turn the printer on and see if the nozzle starts warming up - if it does heat after a power on reset, you've confirmed the nozzle heater driver is shorted. Another clue to what might be happening is if any amber lights are on after a power on reset. Pretty sure there should only be green. An amber LED also implies a shorted mosfet. A creative type handy with a soldering iron can replace them - and save a few bucks. But ... if you haven't done component replacement on multilayer boards, $100 might be cheap.

Posted : 22/05/2021 3:27 am
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