docs

Author: CamDavidsonPilon

user-guide/50-Troubleshooting/Stirring troubleshooting.md

@@ -49,6 +49,12 @@ Detach the top faceplate. Under the faceplate, slightly unscrew each of the four
 2. Try moving the fan closer to the vial holder by _gently_ tightening the screws on the bottom of the top faceplate.
 2. The liquid in the vial may be too viscous for the mixing to work.
 
+### Stir bar goes out of balance during OD dodging (RPM changes)
+
+If the stir bar stops, vibrates, or starts orbiting the vial when OD dodging changes the target RPM:
+1. Make sure a stirring calibration is active. Re-run it if you recently updated software or changed power/hardware. See [stirring calibration](/user-guide/hardware-calibrations#stirring-calibration-optional).
+2. Check that the vial is fully seated on the heating pad. A small gap (for example, from an o-ring or debris) can make the bar lose sync during RPM transitions.
+
 ### Stirring is not able to keep a steady RPM
 
 1. Consider decreasing the value of `Kp` in the section `stirring.pid` in the config.ini by 50%.

user-guide/99-common-questions.mdx

@@ -131,6 +131,10 @@ Stirring is performed with a micro stir bar inside the vial, controlled by a pai
 
 Of course! The maximum length of a stir bar is 20mm. Keep the height low as to not interfere with the optics. (The provided stir bar is 3mm high). Try using other stir bar shapes / designs!
 
+### Why does the stir bar stop or wobble when OD dodging changes RPM?
+
+This is usually a calibration or seating issue. Make sure a stirring calibration is active (re-run it after software updates or hardware changes) and confirm the vial is fully seated on the heating pad. Even a small gap, for example from an o-ring or debris, can make the bar lose sync during RPM transitions.
+
 ### The magnets rub against the plastic screws above them, causing the stirring performance to be degraded / stop. How do I fix this?
 
 Detach the top faceplate. Under the faceplate, slightly unscrew each of the four metal screws. This will add more space between the magnets and the plastic screws.
@@ -279,4 +283,4 @@ See steps [here](/user-guide/updating-software#method-2-update-using-a-zip-file-
 
 ### If I have multiple Pioreactor leaders on my network, what leader does `http://pioreactor.local` point to?
 
-If there are multiple leaders on the same network, then each will override the other's `pioreactor.local` alias, and the alias will be unreliable. You can either access the leaders by their hostnames: `http://<leader hostname>.local`, or you can change the alias in the config.ini, too, by editing `domain_alias` under section `[ui]` (changing this requires a restart of the machine).
+If there are multiple leaders on the same network, then each will override the other's `pioreactor.local` alias, and the alias will be unreliable. You can either access the leaders by their hostnames: `http://<leader hostname>.local`, or you can change the alias in the config.ini, too, by editing `domain_alias` under section `[ui]` (changing this requires a restart of the machine).