I just replaced my old hot end with a new one.  This is the old-style Max V1 version.  After installing it, it seems like it's working fine.  I ran the PID Autotune on it and updated the EEPROM but when setting an extruder temperature, the nozzle won't quite reach it.  It's stopping, and holding steady, about 2 degrees shy of the 200C target when I turn the heat on manually.
During the Autotune, it will peak up just over 200C, so I think it's heating alright.  It seems like the tuning is maybe a bit too aggressive and not letting it come up to temp.  It's rock-solid at 197.5-198 but won't get to 200.
Are there any of the Kp, Ki and/or Kd values that I can tweak manually to help it get there?
This is using the latest SeeMeCNC Rep firmware and Rep Host 1.6.2.
			
			
									
						
										
						Not reaching temperature after PID Tune
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				Polygonhell
 - ULTIMATE 3D JEDI
 - Posts: 2417
 - Joined: Mon Mar 26, 2012 1:44 pm
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Re: Not reaching temperature after PID Tune
This is a pretty common issue with autotune results.
Reduce I and D.
			
			
									
						
							Reduce I and D.
Printer blog http://3dprinterhell.blogspot.com/
			
						Re: Not reaching temperature after PID Tune
When my son and I had issues like this, it was the fact that the new hot end had a different Thermistor type and the setting needed to be adjust in the firmware.
			
			
									
						
										
						Re: Not reaching temperature after PID Tune
Could you please elaborate on this or direct me to a reference? I am having this same problem, holding slightly below set temperature; if I push it over by setting much higher and then turn it back to the set point it bleeds heat rapidly until I'm extruding nearly solid plastic.TwoTone wrote:When my son and I had issues like this, it was the fact that the new hot end had a different Thermistor type and the setting needed to be adjust in the firmware.
I didn't make any changes to the printer but had recently pushed it hard with two 24 hour prints in a long weekend. Reddit wisdom suggested a thermistor issue as well. I have replacements coming but don't know about updating the firmware.
EDIT: I'm going to start with this http://forum.seemecnc.com/viewtopic.php?t=5562 but if you have any tips they would be appreciated.