[Stirrer stops working after 1 hr 10 minutes]

[ErosKuikel]

Hello, my boss showed me a problem with the magnetic stirrer: problem that the stirrer stops working after some time according to her. I setup the ChiBio and after about 1 hour 10 mins, it stopped running. I was wondering what the problems could be??
Some Context: After the stirrer stopped working, I lifted up the glass tube a little and the stirrer started working. But shortly after that, the application failed message popped up in the terminal.
What could be the possible problem and any solution for this>?
Here is the terminal output of the macbook:
[2021-12-11 02:22:34 +0000] [14877] [INFO] Starting gunicorn 20.1.0
[2021-12-11 02:22:34 +0000] [14877] [INFO] Listening at: http://192.168.6.2:5000 (14877)
[2021-12-11 02:22:34 +0000] [14877] [INFO] Using worker: sync
[2021-12-11 02:22:34 +0000] [14880] [INFO] Booting worker with pid: 14880
2021-12-11 02:22:42.143691 Starting watchdog
2021-12-11 02:22:44.628766 Initialising devices
2021-12-11 02:22:44.859427 Initialised M0, Device ID: 38923182921295245632
2021-12-11 02:22:45.426932 Start Up Complete
2021-12-11 02:23:10.568363Calibrated OD
2021-12-11 02:23:15.291594Calibrated OD
2021-12-11 02:23:19.905195 Set item: OD to value 0.5 on M0
2021-12-11 02:27:54.492537 Set item: OD to value 0.5 on M0
2021-12-11 02:27:55.839611 Set item: OD to value 0.5 on M0
2021-12-11 02:30:25.733364 Failed Multiplexer Comms 1 times
2021-12-11 02:30:26.783198 Failed Multiplexer Comms 2 times
2021-12-11 03:31:42.067565 Failed Pumps comms 1 times on device M0
2021-12-11 03:31:42.089745 Failed Pumps comms 2 times on device M0
2021-12-11 03:31:42.111533 Failed Pumps comms 3 times on device M0
2021-12-11 03:31:42.133435 Failed Pumps comms 4 times on device M0
2021-12-11 03:31:42.155506 Failed Pumps comms 5 times on device M0
2021-12-11 03:31:42.177480 Failed Pumps comms 6 times on device M0
2021-12-11 03:31:42.199443 Failed Pumps comms 7 times on device M0
2021-12-11 03:31:42.221380 Failed Pumps comms 8 times on device M0
2021-12-11 03:31:42.243157 Failed Pumps comms 9 times on device M0
2021-12-11 03:31:42.265013 Failed Pumps comms 10 times on device M0
2021-12-11 03:31:42.286843 Failed Pumps comms 11 times on device M0
2021-12-11 03:31:42.308160Failed to communicate to a device 10 times. Disabling hardware and software!
[2021-12-11 03:31:42 +0000] [14877] [INFO] Shutting down: Master
[2021-12-11 03:31:42 +0000] [14877] [INFO] Reason: App failed to load.

[harrison]

Hello,
What version of the reactor do you have? It should say on the outside of it V1.1, V1.2, etc…
Some of the older versions sometimes had stalls with stirring, which we fixed in subsequent generations.
Regardless, the best approach to avoid this would be to use a smaller stir bar, or one that is “easier” to turn (e.g. has few sharp edges), and run at a higher speed.

[ErosKuikel]

Hello. The ChiBio version I am referring to is V 1.0. Got it! Thanks for the suggestions. Will communicate this to my boss.

[saurabhmalani]

I have sometimes experienced stalling with stirring too, my reactor is v1.2, is this version supposed to have had the stirring issue rectified?

[harrison]

Hello, I am not sure exactly which reactors do/don’t have it rectified since they are put together at the manufacturer so I don’t see the interior. Could you tell me the height of the reactor – measuring just the PCB/body of it (i.e. ignore the screws/feet on bottom) so I can investigate?

Regardless, the best option would be to follow the advice above, and attempt different stir bars.

[saurabhmalani]

The height of the reactor assembly without the feet is 112.9mm !

I’ll try different stir bars too. Do you have any suggestions for which kinds have worked best in your experience with regards to shape?

[harrison]

Alas I think that means it doesn’t have the fix. You could take the sides off and look if you desire – the change we are looking for is whether there is a 3d printed part approx 1cm high holding the magnets in the bottom above the fan.

[saurabhmalani]

Ah, goodness. Is there any way I can fix it short of requesting a full replacement from LabMaker? I may have access to 3D printers near me.

[harrison]

Have you tried different stir bar designs as I mentioned above? You can get variety packs of different stir bars (e.g. of eBay) and then pick one that gets along with your reactor.

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