Adding second fan/stirrer

I have been thinking about adding a second fan to the Pioreactor for the purpose of stirring my media. I’m currently planning on running three pumps (Media, Alt-Media, Waste), and my alt-media has an insoluble ingredient. I was thinking of using a second fan (along with some magnets) to drive a larger stir bar in one of my media’s.
I’m already using 3 pumps and 1 fan and they are plugged into the 4 PWM channels. Since all PWM channels are in use, would I be able to plug the second fan into one of the LED channels?

Apparently, yes! I just tried it. Even at 8% “led intensity”, our basic 12V 40mm fan does rotate quickly.

Do I think this is a good idea? Maybe - it’s another device that needs power, and with three pumps, heating, and stirring, I worry about brown-outs, so I would advise either using an AUX power for the PWMs, or being careful not to run multiple pumps at once (these are the most power-hungry devices). I also don’t know what the long-term effects are on the fan attached to the LED channels - it may have reduced life since it’s being powered slightly untraditionally - not sure.

I was contemplating using another Pioreactor for similar purposes. That way the media would also be maintained at the correct temperature. Heating would, in my current climate, significantly help solubility. I’d need to find a tall vial to give sufficient volume.

There are of course many non-brand heated stirrer plates that work out cheaper than a whole Pioreactor - but more expensive than a fan and some magnets if you don’t need temperature control.

This was the best I found looking for open source solution: https://youtu.be/Kn-eLq7-Fbw?si=gxjJ0USuT7nd0iXv

Off-topic, but The first time I watched that video, this video on RFID temperature sensing stir bars played next: https://youtu.be/nh1SIfipQs4?si=__VsgXUJnxQZD0lB - got me wondering if for Pioreactor XL a large cross shaped stirrer could manage OD readings, or contain other sensors…

Has anyone had success on this venture? I’m building a flowcell piorector expansion, a la:

and will need to attach at least 4 pumps in order to exchange media from the larger culture vessel and add some feed and pH adjustment medias. I went ahead and ordered this:

to see if I could add more PWMs. I’m a little worried though about how easy attaching the motor cables will be underneath the baseplate for the Pioreactor. Does anyone have thoughts or advice on this?
Thanks.

I’ve also considered just buying another pioreactor HAT since those PWMs are already side facing, but I’m not sure if that would work out.

Hi there! I sadly had to standby the project for now as I just started a pHd and have no time :frowning: But keep us posted if you succeed. If it helps, the issues I had were software-related, the hardware worked well :). I know there is a student who is currently working on the FlavorReactor in the US. Happy to connect you both!

Bests.