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Gentlemen,

New V2 purchase, immediately upgraded to E3D hot end. When doing PID autotune, the hot end will only reach 140 C, where it plateaus. Ultimately the autotune times out and fails. Any ideas what could be causing this? I'm sure it's something simple. Checking with an infrared temp gun shows that the thermistor is relatively accurate.
I appreciate the help.

Check your power supply voltage with the heater on.

somewhere on here there is a tread about the ohms of the heater cartridge. At one time there was some that were not the 40 watt that they were supposed to be.

Voltages are 11.5-11.6 at power supply, to hot end and to cooling fan.

I have done PID autotunes at 125 and 135 degrees, and while values changed, they didn't increase top end temperature.

It's a long shot but what's your Extr.1 PID Max Value set at?

You might have to lower it before running the auto PID then raise it back to 255 and try again.




edit: I guess raise it if it's not at 255 in your case.

Set at 255...

I thought it obvious, but it's worth mentioning that I cannot get the hot end over 140 with manual controls either.

just for shits and giggles, change the max to 128 and run autotune.


Just an odd number and appears to be consistent on the graph

or try it in mattercontrol to see it it's software related.

Okay. So something changed, which is progress.

When PID Max is set to 128....hot end maxes out at 82 C

Already changed to mattercontrol as well..

any luck?

do you have the correct thermister called out in the firmware?

Followed these directions and uploaded to EEPROM in Arduino:

#define EXT0_TEMPSENSOR_TYPE 8

Can you measure the resistance of your resistors?

If I had to guess I'd say you have a resistor meant for 24V.

46 Ohms

That's at the board and the resistor independently

If im not mistaken a 40w heater cartridge should ohm out at 3.3 ohms....

4.6 rather...pesky decimals

dct16 wrote:4.6 rather...pesky decimals

That would put you around 30 watts... hmmm. Now ill have to scratch my head a bit and think about it..

Ok process of elimination time, have you tried to hand feed some abs thru? This would help verify your temp gun.
Second wire in the stock hot end and thermistor (reselect default thermistor #?) And rule out the heater and thermistor.
Also thinking switch wireing to extruder 2 on the rambo and see if its the same problem. Dont forget to select the right thermistor...

Okay, I was going to start with manually extruding ABS. I went to manually heat up the extruder, set it to 235 and it plateaued at 40 C this time. I found that very strange and went to look at my EEPROM configuration in MatterControl. Extr 1 PID Max was set to 44...so I reset it to 255 and clicked save. Repeated manual heat, plateaued again, went back and it was set to 39. Repeated process and its set to 34. Will wire in stock hot end now...

Sounds like you found your bug all ready...

Hooked up stock hot end and there seems to be no problems. Went up to 200 C on autotune with no hesitation.

I'm thinking that there has to be a problem somewhere in the firmware settings, but I've gone over them time and time again...

Any suggestions would much appreciated.

ok try putting the stock thermistor on the e3d and see what happens....