PID Autotune Failed! Timeout

[Mwpr3d]

After searching through the bowels of the internet, I can't seem to find any relevant information regarding the PID autotune timing out. I installed my E3D V6 on my rostock this afternoon and it can't seem to go above 100~ C.

The only modification to it is that I also installed a screw-on thermistor at the same time. I changed thermistor type to 8 per the e3d installation guide, then found some info on the forums that it should be 1 instead. Tried both but had the same outcome, temp slows to a crawl and all but stops around 100C. Finally, i removed the thermistor, and when i hold it between my fingers it registers the temperature change. Assuming its not a problem with the thermistor.

Has anyone encountered this before? Would you guess that I have something configured wrong in the software, or possibly a faulty heating cartridge?

After reading trough these forums for a few hours I have come up with nothing, but I could just be doing something incredibly stupid. Thank you for all your help.

[Nylocke]

What does the thermistor read at room temp? What are your EEPROM settings for heating and PID? The P, I, D, max and min, and other settings?

[Mwpr3d]

NOZ reads 23.6C at room temperature.

Went ahead and took a screen shot of the PID portion of EEPROM settings

[Nylocke]

Your PID Max value is really low. Should be at 255. Probably is your problem.

[Mwpr3d]

Well that did the trick. I was looking in all of the wrong directions for a solution. Thank you so much.

[Nylocke]

I had it happen with my second hotend. I went to do some dual extrusion after doing several firmware updates/tests and somehow the EEPROM got changed. It wasn't heating up fast enough and the firmware thought the thermistor became disconnected. Glad it got figured out before any hair got pulled out

[redoverred]

Again, I'm going to harp on using dead time control for the default method from the factory manual, but no one seems to use it other than me. PID tuning takes a long time and is not optimal for our use case. Dead time control can be programmed into the firmware from the factory (or download, in our case) and will probably not need to be changed. That removes 45 minutes or more of time for a RoMax build and eliminates the once per week PID tuning post.

[teoman]

I started using it.

It is very easy to setup. I probably need to re-measure the time, but it is about constantly 2 degs low but relatively stable.

[JFettig]

Dead time is only a fix because the auto tuning is very poor. A properly tuned pid control will easily outperform dead time. It has little to do with these mistakes and questions.

Proper manual pid tuning is not something easily explained and takes a little time and effort.

[teoman]

It depends a bit on how much you want to spend time on to it. Once i replaced the thermistor and the resistor, i needed to redo the PID, I tested the dead time control and it gave OK results. Did not have to fiddle at all with it. Very noob friendly. I shall play around with it a bit more when i find the time.

PID is not the greatest with systems with a time delay. You could add a smith predictor to it if you really want to be a perfectionist.