Single V4 Extruder First Look.

[Jules]

Gahhhh - you mean I ran it incorrectly for months? Learn something new every day.

[Tim]

Gahhhh - you mean I ran it incorrectly for months?

Not really. . . see the last sentence from my post. It's probably close enough not to make much difference. Some people make too much of a big deal about PID values. They are the basic parameters of the feedback control system that heats the extruder. If the parameters are way off, you'll see it in the temperature graph on S3D; either it will take a long time to get to temperature, or drift a lot, or have a lot of ringing. An ideal set of PID values should give you a critically damped system that gets to temperature in minimum time, overshoots slightly, and then drops to the target temperature and stays there. If that's basically what it looks like it's doing on the temperature graph, then your PID values are probably just fine as they are.

The problem with being too picky about PID values is that there is not such a thing as a single set of PID values, anyway. If you look up the meaning of the parameters for the M303 command, you'll see that you are actually tuning the system for a specific target temperature. And that means that you can tune it perfectly for PLA temperatures, but it will be slightly different for PETg and ABS temperatures. Not to mention that it probably changes with ambient room temperature, humidity, and/or a host of other minor factors.

[Jules]

Okay - that makes sense.

[zemlin]

The PID auto-tune sounds interesting. Mine is OE V4, but it does over-shoot and bounce around a bit on initial heat up. Might try the auto-tune just to see if it smooths it out a bit - not that it varies enough to be an issue, but just for fun. Haven't messed with a PID tuning for a long time.

[DrRobot]

Thanks Tim. That's what I thought. I remember saw a previous post talking about this and the maximum temperature threshold needs to be increased for V4.