reversing fans (for stacking)

after tinkering with this fan for about a half hour, i have sucesfully reversed the direction it spins. the only problem is that it is barely spinning (i dont think both coild are gettin power :-| ).

what i had to do is unsolder both of the magnet coils, and reverse the wires. there are 3 solder points where the wires go, 1 common one with the 2 negatives, and a positive for each coil. i unsoldered them, and moved the 2 original positives to the -, and seperated the 2 original -'s and put them where the positives were. the wires are gold and bronze colored, so i knew which was which and where to put it.i think if this fan was a normal kind instead of having one bug round thing for the coils to go on, had the normal 4 smaller ones facing outward from the axle, it would spin alot betterthan it is. it's been spinning on my table for a half hour now, still going. i think i didnt get good contack on the one ciol. the only problem i have found is the coating on the wire to insulate it. i should have scraped it off before solderin away at it. i will try redoin it after i post this and see how it goes. bit this could be useful for stacking fans, caus we can make our own reverse spinning fans instead of having to find one.

wow thats alot. thanks for readin all of my rambling

why don't you just turn the fan around?

caus then it would be blowint the other direction, too. im doin this for stacking the fans. for best results on stacked fans, they should be spinning opposite directions. so if you just turn around a regular fan and try to stack it, it'll get very little dont, caus they will be opposing each other.

I never really believed in Stacking Fans. I don't find them an improvement.. and you're not making much sense.

You reversed a fan.. So lets say your fan is running the way it is supposed to. The blades on the fan are cupped and spin in that direction: So the blade "cups" are "filling up" with air. I'm hoping that makes some sense to you.

If you were to reverse the direction of the fan, all you'd get is a light breeze as the blades, on the other side of the "cupped" portion, are pretty straight. This procedure is pretty worthless, if indeed this is what you're doing.


Notice how this fan would spin counter clockwise - Making to spin clockwise wouldn't give you much air.

I agree with four4875 that counter-rotating propellers are more efficent, but Ffats comment is also true. Fans are designed and made to rotate in one direction. ur best bet would be a strait blade design (no curving of the blades).

this fan is movin just as much air as it did before i did anything to it. it is an old straight bladed fan, tho.

glad to hear the good news, ceep us updated

Wow, just as much? I'm dumbfounded.

Any pics?

I can attest to the on-directional nature of fans. My dad rigged up a car radiator fan to cool the attic down in the garage, and one way it pushed about as much air as a mouse sneezing. The other blew paper off his workbench in the corner

Yeh he said its a straight bladed one though didnt he, so it should be the same.

I reversed one by messing with the resistors a while back. I also made it varible speed then screwed it all up. but reversing it wont work correctly because of the scoops. I do have an old fan from a way old computer that does spin clockwize. It has a huge center hub. Im gonna try it sometime.

Jfetting, the reason his works right is there are no scoops, the blades are flat.

if my cam wasnt so much crap, i could and would have took step by step pics. bt its crap. sorry :-(