Looking for about 8 computer fans, cheap....
Last weekend we took our daughter and her two friend to the local hands on Children's Science Museum. The unexpected big hit were old computer fans hooked up to a 9v battery and then with markers and some two sided tape sort of made a powered spirograph. The girls loved as did my wife and she wants to make a girl scout thing of it, hence the reason for 8.
Who has a source from some working but cheap computer fans? If they are in your personal possession, I'm willing to pay shipping.
mtn
MegaDork
3/1/22 12:48 p.m.
In reply to John Welsh :
I'll check my storage in a minute I might still have a couple not in service, but try posting an ad looking for old junk towers on your local market place.
Yes, you have whole towers to get rid of then, but in my experience, people are happy to hand them over for nothing just to get them out of the way.
Edit:: I do not, looks like they were used to try to fix my old 3d printer.
I'll check our scrap bin at work. There are probably several good ones in there.
In reply to mtn :
I use a "waterproof" version of those- from what I can tell (and I could be wrong) they are brushless DC motors, where two wires are for power, and the third is expecting a PWM to control the fan speed. I don't use the 3rd wire, and it runs at 100% all the time. Works great for venting a tiny RV bathroom.
I can probably get you eight. I'll look in my stash now but I have a surplus contact I'll reach out to.
I also have a stash at home. How many will you need?
Turns out I somehow don't have any on hand. I did text my friend to see if he can dredge some up.
You guys are great. I know 8 seems like a big request. That gets one per girl scout. I could do less but that is then less fun.
I remember real paint ones at the school carnival when I was a kid....
thinking about it now I wonder how they dried the paint ?
after looking at the picture below , what we had was a 12 inch square of paper on a turntable that spun around fast and you shot paint from a plastic jar , did a few colors and kind of ended up with a tie dye pattern flying out to the outside of the paper...
it was pretty messy.....
Hey John, do you mind sharing instructions for these? My girls would love to try something like this!
In reply to edwardh80 :
I guess one picture doesn't really show the whole thing clearly but it's really ultra simple. Focus on the fan to the left of the picture below. The black fan should have a red wire and a black wire coming out. May be a white wire too to regulate speed but don't use that, it will then run only at full speed.
Add a section of addition wire that ends in an alligator clip. Clip 9v battery to fan; red to positive and black to negative. Starting and stopping the fan was controlled by just unclipping the red.
Add some double stick tape to the center of the fan. Put on a square of white paper. Hold marker to paper while the paper spins. End result is colorful circle on the paper.
Close up picture of the artwork that came home
I just bid on a lot of them at PCI auctions. It just said "box full of cooling fans." Probably had 40 of them in it and I think it sold for $6.
Surplus auctions are fun things.
Norther Tool usually has a box full of them for sale.
Surpluscenter.com may also have them.
In reply to John Welsh :
Awesome, thanks John. I was remembering spirograph (the game from my youth with cog wheels and pens) and was wondering if this was as mathematically complex as that. I'll see if I can give it a bash with them.
I found an Amazon 3 for $9.99 offer for new. Used tend to cost more than that. Add in 5.50 for 25 alligator clips and 10 non-name 9v batteries for $9.00. That gets me 9 fan-things working for under $5 each.
That's a good deal when you factor in shipping. Even if you guys send me fans for free and then $10 for shipping, the savings is less than $20
Toss in a potentiometer on the line and you can lower the speed by adding resistance. A fun electricity lesson.
I don't have any left, but I also bought a box of 30 years ago at a surplus auction for like $5... See if there's any surplus electronics auctions near you?
Otherwise, if you do have to buy them and have some time, maybe try alibaba?
In reply to John Welsh :
I can bash on down to a local junk store near me; comp me back and each will be $0.50/each, if they work (though they typically do if they aren't missing blades).
My surplus friend set aside a box for me. I'm hoping to pick it up tomorrow and can report back what he gives me.
Amazon is easy to return if you end up with good ones!
My stash has been raided by two of my children, though if you still end up needing some I can send a handful.
