Frustrated newbie - Thermal Runaway

I've been struggling with this printer since late summer. I have had spurts where I threw up my hands and left it sitting for weeks. It's been one thing after another, but I finally have everything doing something similar to what it is supposed to. I started with a Hictop Prusa i3 kit. Since then, the controller board was faulty at first, replacement blew up because of my stupidity and took a month to get here from China, so I replaced it with a MiniRambo. I replaced all of the motors, the power supply, and the hot end thermistor. The common problem had been runaway temps without shutting down. So i messed up alot of nozzles along the way as well. I could not get autotune to run as it would fail with max temp, but it did at least shut down the hot end.

I finally got autotune to work by changing PID_MAX to 60.

Then I tried to print a 20mm cube. Started off pretty good, then I got a Thermal Runaway error and it stopped printing.

What I don't understand is that the temperature according to the logs was pretty constant. It does appear that the filament was doing something strange since one side of the cube looked like it had a big glob of filament instead of smooth lines. Also, it looks like some came through around the outside of the nozzle.

Pictures and the last portion of the log is below. At this point, I'm at a complete loss. The temperature graph was super consistent for the short time it was printing and had by no means started to "runaway". Normally I would just ask the Google, but I'm apparently not using the proper search terms as Google is failing me or I don't understand what I'm reading. If someone can point me in the right direction, I'd be extremely grateful.

Not sure what info would be helpful, so I took a guess that this would help:
Firmware: Marlin 1.0.2
Power Supply: Output = +24V 50/60Hz 20A
Values from Autotune:
// PID Autotune
#define DEFAULT_Kp 4.07
#define DEFAULT_Ki .17
#define DEFAULT_Kd 23.63
Thermal Runaway Settings:
#define THERMAL_RUNAWAY_PROTECTION_START_PERIOD 20
#define THERMAL_RUNAWAY_PROTECTION_PERIOD 20 //in seconds
#define THERMAL_RUNAWAY_PROTECTION_HYSTERESIS 4 // in degree Celsius

Attachment 8356"glob" is on bottom side of cube
Attachment 8357"glob" is on right side of cube
Attachment 8358For some reason, pic is upside down, but glob of filament is partially obscuring the brass color of the nozzle on "top" of the aluminum block.

From the log:

Send: N381 M105*45

Recv: ok T:190.2 /200.0 B:0.0 /0.0 T0:190.2 /200.0 @:30 B@:0

Send: N382 G1 X90.250 Y109.750 E12.14959 F1800.000*29

Recv: ok

Send: N383 G1 X90.250 Y90.250 E12.51012*94

Recv: ok

Send: N384 G1 X109.750 Y90.250 E12.87064*103

Recv: ok

Send: N385 G1 X109.750 Y109.675 E13.22977*81

Recv: ok

Send: N386 G1 X109.317 Y109.500 F7800.000*83

Recv: ok

Send: N387 G1 Z2.450 F7800.000*4

Recv: ok

Send: N388 G1 X109.250 Y109.250 F7800.000*93

Recv: ok

Send: N389 G1 X90.750 Y109.250 E13.57180 F1800.000*28

Recv: ok

Send: N390 G1 X90.750 Y90.750 E13.91384*93

Recv: ok

Send: N391 G1 X109.250 Y90.750 E14.25587*101

Recv: ok

Send: N392 G1 X109.250 Y109.175 E14.59652*86

Recv: ok

Send: N393 G1 X109.250 Y109.750 F7800.000*82

Recv: ok

Send: N394 G1 X109.750 Y109.750 F7800.000*80

Recv: ok

Send: N395 M105*40

Recv: ok T:191.7 /200.0 B:0.0 /0.0 T0:191.7 /200.0 @:27 B@:0

Send: N396 G1 X90.250 Y109.750 E14.95704 F1800.000*17

Recv: ok

Send: N397 G1 X90.250 Y90.250 E15.31756*93

Recv: ok

Send: N398 G1 X109.750 Y90.250 E15.67808*97

Recv: ok

Send: N399 G1 X109.750 Y109.675 E16.03721*87

Recv: ok

Send: N400 G1 X109.317 Y109.500 F7800.000*90

Recv: ok

Send: N401 G1 Z2.750 F7800.000*14

Recv: ok

Send: N402 G1 X109.250 Y109.250 F7800.000*88

Recv: ok

Send: N403 G1 X90.750 Y109.250 E16.37925 F1800.000*29

Recv: ok

Send: N404 G1 X90.750 Y90.750 E16.72128*91

Recv: ok

Send: N405 G1 X109.250 Y90.750 E17.06331*102

Recv: ok

Send: N406 G1 X109.250 Y109.175 E17.40396*90

Recv: ok

Send: N407 G1 X109.250 Y109.750 F7800.000*88

Recv: ok

Send: N408 M105*43

Recv: ok T:193.6 /200.0 B:0.0 /0.0 T0:193.6 /200.0 @:24 B@:0

Send: N409 G1 X109.750 Y109.750 F7800.000*83

Recv: ok

Send: N410 G1 X90.250 Y109.750 E17.76448 F1800.000*29

Recv: ok

Send: N411 G1 X90.250 Y90.250 E18.12500*89

Recv: ok

Send: N412 G1 X109.750 Y90.250 E18.48552*102

Recv: ok

Send: N413 G1 X109.750 Y109.675 E18.84466*83

Recv: ok

Send: N414 G1 X109.317 Y109.500 F7800.000*95

Recv: Error:Thermal Runaway, system stopped! Heater_ID:

Changing monitoring state from 'Printing' to 'Error: Thermal Runaway, system stopped! Heater_ID:

'

Recv: 0

I know nothing about that machine, SO...... That nozzle picture is pretty blurry, but it looks like the filament is oozing out between the heated barrel (whatever it's called) and nozzle? Any possibility of noise in the PID loop messing with the controller? How does the controller handle open or shorted sensors? Does it fault with each, or does it give a generic fault?

Quote:

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Originally Posted by pgriffy

What I don't understand is that the temperature according to the logs was pretty constant. It does appear that the filament was doing something strange since one side of the cube looked like it had a big glob of filament instead of smooth lines. Also, it looks like some came through around the outside of the nozzle.

Pictures and the last portion of the log is below. At this point, I'm at a complete loss. The temperature graph was super consistent for the short time it was printing and had by no means started to "runaway". Normally I would just ask the Google, but I'm apparently not using the proper search terms as Google is failing me or I don't understand what I'm reading. If someone can point me in the right direction, I'd be extremely grateful.

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Well it sounds like you at least have a decent understanding of firmware and stuff, which is more than can be said about a lot of newbies.

Why a MiniRambo? Why not just an Arduino Mega with RAMPS?

A false thermal runaway is usually the fault of a broken wire. It was smart to replace your Thermistor, but consider ohming out your thermistor wiring just to make sure there's no intermittent breakage. Also double check the connection at the controller board.

The next place I would look is into your firmware. Marlin is old, unsupported and generally "meh". Look into Repetier and consider trying their firmware. Setup is pretty easy with the firmware configuration tool. Most settings are safe at default:

http://www.repetier.com/firmware/v092/

Oh and yeah...you have a poorly seated nozzle, hence the blob leaking out of the side. You should unthread the brass nozzle from the aluminum heater block, thread the aluminum heaterblock further up the steel heatbreak and then thread the brass nozzle back in so it bottoms out on the steel heatbreak and not the aluminum heaterblock. Hope that makes sense.

Quote:

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Originally Posted by LuckyImperial

The next place I would look is into your firmware. Marlin is old, unsupported and generally "meh". Look into Repetier and consider trying their firmware. Setup is pretty easy with the firmware configuration tool. Most settings are safe at default:

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LuckyImperial... STOP BASHING MARLIN !!! Marlin --IS-- supported. And I would argue more feature rich than Repetier. Do your recruiting for Repetier on another bulletin board.

Quote:

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Originally Posted by Roxy

LuckyImperial... STOP BASHING MARLIN !!! Marlin --IS-- supported. And I would argue more feature rich than Repetier. Do your recruiting for Repetier on another bulletin board.

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Whoa...

I'm in no way affiliated with Repetier. I just like it more than Marlin. I come to this board to help people who are having issues...most of whom do not understand Marlin.

I promote Repetier because it has a great online configuration utility, it has the ability to interface with Repetier Host well (a common client), and it allows eeprom changes with ease assuming the use of Repetier Host.
I want to be clear that I am in no way trying to troll or illicit a negative reaction from anyone. I am just stating my experiences.

With that said...can you point me to the latest version of Marlin with Delta and Cartesian support? Or a version that allows GUI eeprom editing? I'm definitely interested in trying it.

The latest Release Candidate supporting both Delta's and Cartesian machines is at: https://github.com/MarlinFirmware/Marlin/tree/RC

Quote:

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Originally Posted by Roxy

The latest Release Candidate supporting both Delta's and Cartesian machines is at: https://github.com/MarlinFirmware/Marlin/tree/RC

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1.1.0! New to me. Thanks.

Update - Progress made. Noticed that the insulation on the wires connecting the heating element had come off. wrapped those in kapton tape and got a full print of a 20mm x 20mm x 30mm cube. Looks like I have some tuning to do, but at least I've gotten a print. Finally.

Nice Find!! Hope that solves it for you.

I have had a similar problem with bed going to max setting even though printer said bed temp was zero. Problem, I suspect, is that they do not put arc suppression on relay contacts so they are when open or close which damages contacts and eventually welds them shut. The fix is to take a 47 to 100 ohm resister and a 1 micro farad capacitor, solder them together in series that is one end of the resistor to end end of the capacitor, do not solder the other ends together, now take the ends of this device you have just made and solder one end to one contact of the relay for the bed, and solder the other end to the other contact of the bed, you can also do this by inserting the ends across the two screw lugs with the wires that are there. This will suppress the arcing in the relay and protect the contacts. I haven't had a problem since.