About to try Marlin1.1.0RC4...

[ROBOCOP]

Thanks . Ill try it

[printbus]

Robocop - Are you printing with the bed heated? What hot end are you using, and how is the thermistor attached to it? How is the wiring to the hot end bundled and routed? I'll bet that what is happening is the cabling to the hot end is shifting as you print higher up, this causes the thermistor on the hot end to shift a bit, and the thermistor is no longer monitoring the hot end temperature properly.

Thermal runaway has nothing to do with motor temperature, driver temperature, or the temperature of your RUMBA board. Unless the new Marlin changed things, thermal runaway means either a hot end heater or the bed heater couldn't be kept at the set temperature for unusually long time. The suspicion here is that the heater is actually on constantly or close to it and there's a problem measuring the temperature correctly. If so, the heater could be in a thermal runaway situation where it is overheating. The printer shuts down as a safety precaution.

If a thermistor doesn't maintain good thermal connection to what it is measuring, it starts reading lower temperatures than it should, and the heater will have a tougher time maintaining the set temperature....

[ROBOCOP]

What would you recomend i change these to?Like 60sec and 2degrees ?

If you get false positives for "Thermal Runaway" increase THERMAL_PROTECTION_HYSTERESIS and/or THERMAL_PROTECTION_PERIOD
*/
#if ENABLED(THERMAL_PROTECTION_HOTENDS)
#define THERMAL_PROTECTION_PERIOD 40 // Seconds
#define THERMAL_PROTECTION_HYSTERESIS 4 // Degrees Celsius

The problem may also be because their is no fan on the Rumba board. (Which i will be adding)It was never a problem with the old stock Makerfarm firmware but i know the Rumba was always pretty hot. The mesh leveling is a major plus for this printer as the MF heatbed is always pretty warped.

Btw in another question i noticed the reprap full graphics lcd no longer shows the percentage of the print. Is there a way to add this back?

Last question. With mesh the prints are looking great except for slight bulging of the corners . What settings can correct this?

[ROBOCOP]

Robocop - Are you printing with the bed heated? What hot end are you using, and how is the thermistor attached to it? How is the wiring to the hot end bundled and routed? I'll bet that what is happening is the cabling to the hot end is shifting as you print higher up, this causes the thermistor on the hot end to shift a bit, and the thermistor is no longer monitoring the hot end temperature properly.

Unless the new Marlin changed things, thermal runaway means either the hot end heater or the bed heater is on constantly for a duration exceeding a set threshold. The heaters should toggle on and off at a rate far quicker than the set time threshold while the desired temperature is being maintained. The idea with the thermal runaway detection is that if the heater can't maintain to the set temperature, the heater will stay on constantly. If so, something is wrong and the printer shuts down as a safety precaution.

If a thermistor doesn't maintain good thermal connection to what it is measuring, it starts reading lower temperatures than it should, and the heater will be turned on for longer an longer periods of time....

Nothing changed hardware wise from the old firmware i was running which always printed fine. Yes i am printing PLA with stock Makerfarm 12" heated bed / relay with boro glass top. The hotend is a Hexagon with tapped screw in 3mm 100k epcos thermister( I can see that causing the issue but its been working previously. ) The cabling is zip tied to the wades so it doesnt move near the hotend. The temps on the LCD stay within 1 degree plus or minus while in print it looked like and the print is printing very good. The temp seems dialed in from the looks of the part. If the hotend remained heating wouldnt it not print good cause of the filament being too hot?

[printbus]

... If the hotend remained heating wouldnt it not print good cause of the filament being too hot?

Well, the bulging at the corners could be a sign of too high of a temperature...

Are there two additional thermal runaway lines in the configuration file for the bed? Are they also uncommented? I'm just trying to understand which of the two temperature control circuits is tripping - hot end vs. bed. Does the error message on the display add any insight? Were you monitoring the temperatures displayed on the LCD or on control software right at the point of shutdown? If I understand Marlin thermal runaway, a temperature should have been reading low by at least the thermal runaway hysteresis amount before the trip occurred. That would answer whether the problem is with the bed or the hot end.

Note that I don't believe any MakerFarm firmware configuration has thermal runaway protection enabled, so you probably didn't have that in your printer until now. It could be that whatever issue you have now, you've always had.

[printbus]

Here are two threads that talk about having thermal runaway problems on a MakerFarm printer -

http://3dprintboard.com/showthread.p...-ambient-temps - Here the problem was a bit too much print cooling fan airflow in at a cold ambient temperature tripping the hot end thermal runaway.

http://3dprintboard.com/showthread.php?10166-Thermal-Runaway-Protection-(Dual-Extruders) - Here the problem was the heated bed, but the OP didn't come back and say what he did to fix the problem. Like here, the thermal runaway problem showed up as soon as he enabled detection for it.

[ROBOCOP]

There are these 2 lines
#define THERMAL_PROTECTION_HOTENDS // Enable thermal protection for all extruders
#define THERMAL_PROTECTION_BED // Enable thermal protection for the heated bed

I think i may have found something though. Not sure if it can cause the issue but the thermister in the hot end is a 100k 3950 which is option 11 and i forgot to change it in the firmware . Right now its set at 1 (100k epcos) . I gotta go check the printer . Its actually not my printer. I bought it for my brother a while back so its at his house. The error message just said thermal runaway on the lcd so not sure if its the bed or hotend. Im leading toward hotend. I didnt see the temp right when it went to thermal runaway. I did monitor it for the first half of the print when it was fine. I need to check again and fully monitor the temps. Im heading over there now so i will report later. Thanks for the help. I appreciate it.

[ROBOCOP]

Ok so i went over there to check things out and when i went to turn the printer on it wouldnt . Power supply was dead. I did notice even before i printed anything yesterday the LEDs and hotend fan were like flickering so im wondering now if it was already on its way out . Anyway gotta wait until a new PSU comes in before going any further. It a cheap 12v 30A LED type PSU.

[printbus]

Robocop - so now you have the quandary of was it a heater/thermistor problem that put a more extensive load on the power supply, or a failing power supply that couldn't heat things properly... Others have had early failures with the LED-type power supplies, so you're not alone there. My vote would be the failing power supply couldn't maintain the high load necessary for the heat bed as the power supply warmed up. Flickering lights is a good sign of this. If the power supply output is lower than it should be, the heaters will be dissipating less heat than they should. If the power supply output is bad enough, the heaters won't be able to reach the set point, leading to the thermal runaway protection kicking in. The wrong thermistor setup would have caused the hot end temp to read low by about 15 degrees at a 200 degree setpoint. While an error, it shouldn't have been a big enough error to create the thermal runaway detection. At bed temperatures, the thermistor error would have only been a few degrees.

I've looked at the thermal runaway code in at least older versions of Marlin. I've corrected some inaccuracies in my first post. Robocop is correct that the LCD won't show which heater is the problem. If the printer is connected to host software however, the host software should be getting a thermal runaway message that includes various detail. A HEATER ID value between 0 and 8 correlates to an extruder number; a value of 9 correlates to the print bed.

Since my last post, I've realized Robocop doesn't have a MakerFarm printer. Somewhat getting back to Lakester's context and this being the MakerFarm subforum, I think a key point of note is that thermal runaway detection is disabled in MakerFarm builds, but is enabled by default in the Marlin github repository files. MakerFarm owners that get thermal runaway errors when migrating to the new Marlin should likely assume they have hardware issues that have been going undetected with their old firmware. The errors are not likely to be due to setting changes in firmware or with their slicer. To determine what is causing the thermal runaway possibility, you either need to monitor the LCD for measured temperatures that aren't staying at the set point, look at the serial messages being sent to host software, or perhaps go in and disable thermal runaway for the bed (where the need is arguable anyway) and see if that causes the error to no longer occur.

[ROBOCOP]

Powersupply should be in tuesday. Then i can do some tests. I didnt have the printer connected to the computer at the time to see the communication. I will do so when testing with the new PSU. The printer is a Makerfarm I3v 12" .You are correct i believe in that the original makerfarm marlin firmware didnt have thermal protection. The heatbed is a 300W heatbed with a relay switching power directly from the PSU so it does need like 25A. I have heard the LED type PSU's failing out of nowhere which does make it hard tell if was because of load . I do have a 30A fast blow fuse inline and the fuse is still intact. Also using heavy 12Ga silcone wire for the heatbed and relay. If it does turn out to be a heatbed issue that went unnoticed with the old firmware i will probably change the heatbed. 25A is a bit overkill. Probably go with a lower wattage kapton heater with aluminum heatspreader like on my other printers. Never been a fan of the PCB type anyway cause of the warping.

I know i read of some people having thermal issues with the 12" Makerfarm heatbed and toasted relays and PSU failures.

I found this thread which seems to be just like my issue.
http://forums.reprap.org/read.php?262,604700