I honestly think this is the worst use case for a 3d printer. The part isn’t improved by printing. You can buy the part easily. The cost of modelling time and printing is more than the replacement. There’s a decent chance the replacement part would have arrived quicker than the print took… Sorry to be a bore, it’s better than an octopus or another benchy, I’ll give you that.

Nice

A quick search for 2 channel 24v fan controller yealded the below link. Not saying this is ideal for your scenario but something similar will work and can be powered with a power brick. Doesn’t look like it comes with instructions though so I’m not sure what current it requires. The temperature sensor could work to make it turn on when the printer heats up as well.

https://www.amazon.co.uk/Channel-Temperature-Controller-Governor-Display/dp/B083R97GZ1

I disagree that the main reason is thermal runaway. It is more likely to be underrated components that can’t handle the current. This would not be immediately apparent and does usually come from lower quality printers.

Voron allow you to configure a printer and the provide a spreadsheet suggesting the sources for buying the parts. They aren’t region specific but most of the vendors are multinational.

This is my course of action with anything I buy.

1. Is there an ethical source
2. Is there a second hand source
3. Is there a EU company that may source the manufacture in China
4. Rarely, buy the Chinese one

I have a Fitbit sense, it has a blood oxygen estimation but not constant, doesn’t really do blood pressure.

If you are just looking for those metrics then it doesn’t do a bad job, basically a lifestyle tracker. If you are looking at it from a sports perspective I’d recommend a Garmin over a Fitbit.

I don’t have any experience with any others though.