How to remove the rotor from a fan?

[Crazy Jayhawk]

I have a 120mm fan that seems to turn the wrong direction. If you look at the blades on a normal fan, they curve from fairly flat at one edge to nearly vertical at the other, with the vertical side being the outlet.

I think mine's set up wrong as it turns the opposite direction. I think this is also making it produce a lot of noise. What I want to do is take off the rotor and then turn the motor around backwards. Is this doable?

[Phil]

I've got to see a picture of this as I just can't see in my head what you mean, even just a sketch in ms paint or something (turn it too a jpeg first though.

[Crazy Jayhawk]

The black line is a cross section of a fan blade. The blue arrow represents the direction the fan blade *should* move through the air, and the red one shows which way the blade actually moves. I think its incorrect orientation is creating turbulence.

[Phil]

thats odd, what make and model is it (on the sticker on the bottom)

[YMAN]

I have taken the blades and bearings off Fans.
It is simple but many times the bearings wouln't
come out without snaping the bearings off the blades!
(I put too much pressure)

Just pull the blades off the base!
I am not responsable if you damage your fan!

There is also a washer type thing under the lable on the back
of the fan that holds the bearings in place.

[Crazy Jayhawk]

I figured it out. It's a Radio Shack 120mm fan, and I've modified the rotor on it so it works right.

[YMAN]

Tell us how you fixed it.

[Crazy Jayhawk]

Originally posted by YMAN
Tell us how you fixed it. I pulled the rotor off of the fan. There's a little plastic cap on the motor side you have to pry off, then a little clip under it.

Once the rotor was off I did a few things:

1. Remove magnetic ring.
2. Slice top plate off of rotor and sand it flat. I'm effectively turning the rotor upside down, which corrects the blade problem.
3. Put magnetic ring back in upside down relative to its original position. This way it'll be in the same orientation relative to the rest of the motor.
4. Super glue the cap onto the opposite side of the rotor.
5. Reattach rotor when glue dries.

[JigPu]

Couldn't you have just reversed the voltage? I mean, with every DC fan i've seen, changing the + and - around will make the motor spin the other way... Mabey I'm just stupid, but did I miss it being described as an AC fan or something?? :confused:

JigPu

[Phil]

Originally posted by JigPu
Couldn't you have just reversed the voltage? I mean, with every DC fan i've seen, changing the + and - around will make the motor spin the other way... Mabey I'm just stupid, but did I miss it being described as an AC fan or something?? :confused:

JigPu

I'm not sure why but that doesn't work with the motors in fans

[Crazy Jayhawk]

Originally posted by JigPu
Couldn't you have just reversed the voltage? I mean, with every DC fan i've seen, changing the + and - around will make the motor spin the other way... Mabey I'm just stupid, but did I miss it being described as an AC fan or something?? :confused:

JigPu Tried that. Didn't work.

[KeyboardCowboy]

couldn't you just have reversed the the wires, ie switch their places??

[William]

Originally posted by KeyboardCowboy
couldn't you just have reversed the the wires, ie switch their places??

i don't think this is too good on the motor though.

[Crazy Jayhawk]

Originally posted by KeyboardCowboy
couldn't you just have reversed the the wires, ie switch their places?? I think the motor has a diode built into it somewhere. It only runs one way.

[YMAN]

I think the motor has a diode built into it somewhere. It only runs one way.

Yes, it does have a diode. Also I dont think the transisters
and other components work backwards as well!