ah, hm, yes your theory of in sufficient power is possible then. And if you manually kick the fan with a pen or stick, does it start up?
Larger stir bars, like a cross shape, and heavier, have more inertia, and more liquid to initially move. I imagine if you used the AUX power power to add a 6V to 12V to the PWM rails, that could work (but requires more cables and outlets…), since it’ll provide more power (voltage) to the fan to start.
Is this is same as the original issue? Like, when you were first seeing “RPM is 0” errors, was the fan stopped, or was it just not being detected?
Hey Cameron, currently we are trying again and it is very nice to see the temperatures being stable at 60 °C without any errors. Regarding the stirring, I developed a theory that it might be that there are different batches of glass vials we have that have a thicker bottom for some reason that hampers the stirring. Explaining the ‘random’ occurrence in different reactors. Still weird that it only starts being an issue after heating up of the reactors though. I will get back to you on this!
We also have some glass vials which we tested from a third supplied and I can confirm that some of the glass vial bottoms do influence the stirring. Hence, I do not think it is an issue caused due to heating :)).
Can you two tell me about that how thick the new vial bottoms are? Magnetic fields decrease squared with distance, so a few millimeters might matter.
The new Pioreactor v1.1 design has moved the stirring fan closer to the stir bar (by using counter sunk screws in the bottom of the vial holder), and may help here.
We can try to measure the thickness, however, I think it is more like small deformations rather than intentional increase in thickness. Hence, it can be difficult to get measurable value.
It can also be due to the shape deformation (e.g., having “n” shaped bottom) which might be the issue rather than the thickness.
We also obtained v1.1 in house and can potentially test if some of the glasses which caused problem in v1.0 can be used in v1.1.
Will provide more information next week if I find time to run some tests