Powered it up with my new seal in place, and I just succeeded in burning out at least one phase of my impeller drive motor. It still runs if I remove the load and give it a spin.

My seal was too tight (at least at room temperature), so the motor was stalled and it released some of the magic smoke.

The magic smoke is rather hard to get back into things.

I've stalled it before for much longer without burning it out. It was a 15v motor and I was only running it at 12v. Guess that didn't save me this time.

I have a slightly larger replacement. Well, the 'can' is larger at least. That's probably a good thing as I believe I was running the previous one near it's torque limit. Still 5 phase, same voltage.

I'll need to machine a new shaft coupler and modify the mounting a bit as the new motor is metric. This also eliminates the last non-metric part in my print head. Perhaps it's fate. :)

Now would be a good time to add some feedback so I know if it stalls. I had already wired the optical input which would make my cheap DC motor into a proper servo, but I never actually plugged anything into it. I have also not implemented the software feedback loop, set limits, or actually wired the other end up to the Beaglebone.

I could also use the applied PWM duty cycle versus the resulting RPM to roughly calculate the viscosity of what I'm mixing if I'm smart... Not sure what I'd do with that, but hey..