<p>I have a Monoprice Maker Ultimate 3D printer (a rebranded Wanhao Duplicator 6) and out of the box the hotend temps when set to 200 would vary between 190 and 210. I used repetier-host to run <a href="https://reprap.org/wiki/PID_Tuning" rel="nofollow noreferrer">PID tuning</a> and stored the last set of values it gave when it finished, however I'm still seeing around 5 degree temp swings.</p>

<p>Here's a screenshot of the temp during a Benchy print from Octoprint:</p>

<p><a href="https://i.stack.imgur.com/I3HxO.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/I3HxO.png" alt="Temperature swings"></a></p>

<p>I tried PID tuning again, which gave different values, but basically the same results. Is there anything I can do to improve this? The Maker Select Plus I had only seemed to vary +/- 1 degree so I'm assuming this is more than expected. (I don't actually know what the implications are, so I don't know whether it is/will affect my print quality).</p>

<p>Is there another way of tuning (I don't fancy manually tweaking numbers and testing for hours), or if I do more than 8 cycles (the default on the Wiki page linked above) would that improve the accuracy?</p>

[{'answer_id': 7670, 'author': 'Trish', 'author_id': 8884, 'author_profile': 'https://3dprinting.stackexchange.com/users/8884', 'pm_score': 0, 'selected': False, 'text': '<h1>Software</h1>\n<p>You might want to look at your firmware. When running a PID tune, the firmware decides on a smoothing.</p>\n<p>in Marlin, <code>configuration.h</code> contains a line that determines how much the machine shall try to work out the curves. For my ender 3 it reads:</p>\n<pre><code>#define PID_K1 0.95      // Smoothing factor within the PID\n</code></pre>\n<p>Playing with the value carefully might result in better calibration.</p>\n<h1>Hardware</h1>\n<p>A different trick to <em>widen</em> the waves might come from adjusting the physical properties of the printer:</p>\n<ul>\n<li>Make sure that no draft from the cool end fans runs over the heater block. If it does, a shroud or a little tinfoil can help to dampen the changes.</li>\n<li>e3D uses a silicon sock to isolate their heater blocks and prevent air drafting over them.</li>\n</ul>\n'}, {'answer_id': 7673, 'author': '0scar', 'author_id': 5740, 'author_profile': 'https://3dprinting.stackexchange.com/users/5740', 'pm_score': 2, 'selected': True, 'text': '<p>If you are sure that PID is enabled (and not using bang-bang heating, as this gives a very similar heating profile) and did not fix the fluctuations, the best guess for this phenomenon is that the printer board has incorrect capacitors installed on the printer board. This is not very uncommon and can be found on the internet. You should at least show the graph to the vendor and ask for support.</p>\n\n<p>If incorrect or faulty capacitors are the cause it requires desoldering, and resoldering new ones. If this is out of your comfort zone, it is better to steer your communication with the vendor to replacing the board.</p>\n'}]
['https://3dprinting.stackexchange.com/questions/7661', 'https://3dprinting.stackexchange.com', 'https://3dprinting.stackexchange.com/users/13607/']