Connect two fans in series?

I just got a 80mm fan and a 40mm fan online. I plan to use the 80mm one to cool off the print and 40mm one to cool off RAMPS.

I checked and saw a small driver that sells more than $10 which seems to me too expensive. I am thinking maybe to connect the two fans in series would work, by which I mean connect one of the fans' (-)to the other fan's (+), and connect the first fan's (+) and the second fan's (-) to the board. I'm not sure if it might work:

1) will the current be enough?
2) 80mm fan requires more amps, is it fine to connect them like that?

you'll probably find that the 80mm fan won't spin as fast as the 40mm fan, if at all.

in series they will both spin at 50% of normal speed anyway, even if the current draw was the same for both fans.

what about connecting your 40mm fan straight to the power supply (through a fuse!) so that it's always running when the printer is turned on?

Thanks, sounds good!

Why not just connect them in parallel? Anything that can drive one fan should not have a problem driving 2. They use less than 0.2amps normally.

That might work.. I'll try that out.


What about just double "max fan speed" on my slicer. Will that work? My guess is still the 80mm one would be slower, but 40mm will be at the normal speed.

that would only work with 6v fans. 2 fans connected in series with a 12v supply will get 6v each, Max. If you set the max fan speed to 255 (which is the max) you only get 12v still. Its simple electronics.

The best way to do it is to connect them in parallel.

Sounds good! Should I still double the max speed to let them work faster?