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So I started using Cura a few weeks ago, and when I print it goes to 204 Celsius instead of 200. It doesn't really affect my print quality but I just want to know if there's a fix for it. My printer is a Da Vinci Jr 1.0.

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  • $\begingroup$ I'm not gonna write this as answer. But mine does the same. It only does it at start and eventually stabilizes to set temperature during the first layer. $\endgroup$ – Athanasios Karagiannis Oct 25 '17 at 15:25
  • $\begingroup$ Does it stay fixed at 204? If so, just change the Cura setting to 196. For that matter, all you should care about is the print quality. The exact temperature is not a hard and fast parameter. $\endgroup$ – Carl Witthoft Oct 25 '17 at 15:26
  • $\begingroup$ @AthanasiosKaragiannis All closed-loop systems (heat source controller plus thermocouple) take time to stabilize. If you care, manually set the head temperature prior to initiating the gcode print sequence. $\endgroup$ – Carl Witthoft Oct 25 '17 at 15:27
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    $\begingroup$ Check your advanced settings. Some slicers increase the temperature for the first few layers to increase bed adhesion. $\endgroup$ – Aaron Cofield Oct 25 '17 at 22:48
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    $\begingroup$ Check your settings, exists initial temperature (bed adhesion) and layer printing. Also your fan could be working in a lower speed. $\endgroup$ – Fernando Baltazar Oct 26 '17 at 6:48
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Its mainly due to the regulation loop of the PID Regulator implemented in the Firmware of the Da vinci jr. The P-Factor is a little bit too high. This is the reason why the temperature "overshoots". Because the Printerhead and Nozzle has some volume which is heated up. It takes time to cool down after it has detected an overshoot.

here you can find additional informations about it: https://innovativecontrols.com/blog/basics-tuning-pid-loops

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    $\begingroup$ As a note, this is fairly common in most printers. I haven't seen a response to the comment on your question as to whether it STAYS at 204C. If that's the case, that's something different. But if it hits 204 then goes down to 200, that's just regular operation. $\endgroup$ – Jesse Williams Nov 10 '17 at 16:46
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That's called PID overshoot. All control loops have varying types of outliers like this. Sometimes, you can't overshoot, sometimes you cant undershoot. But it's a remnant of the math.

The solution here, is to PID Tune. Once you get an established Kp Ki and Kd constants, then you can either save it to eeprom or you can recompile your firmware with this change.

It's pretty common, especially if you have different hotends without known profiles. PID tuning also works on heated beds as well. But usually those use what's called Bang-bang.

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