RC India

RC Equipments => Electric Power => Topic started by: Snehal.Samar on May 10, 2011, 03:26:38 PM



Title: Computer Ducted Fan
Post by: Snehal.Samar on May 10, 2011, 03:26:38 PM
Hi friends, :)

I was just wondering that can computer fans be used as ducted fans for flying plane??
If somebody here is already flying with that ,then please share your experience with us.

Thnks
Snehal


Title: Re: Computer Ducted Fan
Post by: iamahuman on May 10, 2011, 03:35:16 PM
I was planning on trying it long ago but was told that it would be impractical.Now when I look back at it,it seems totally impractical.


Title: Re: Computer Ducted Fan
Post by: Snehal.Samar on May 10, 2011, 03:45:43 PM
What if i change the motor of the fan..?? Is the fan aerodynamically not correct??


Title: Re: Computer Ducted Fan
Post by: sundaram on May 10, 2011, 03:51:24 PM
Computer Fans are not ducted fans they are merely cooling fans or you might say exhaust fans. As the name imply they are of very low RPM designed for sustained operations for long hours. They have built in Speed controllers. Their Magnets are also of material similar to Magnetic Rubber. Not the strong strontium/ Neodymium magnets which is used in normal Brushless motors.

The CPU fans are having a variable speed controllers controlled by PPM input from the mother board based on the temp variation of the CPU IC core.

You can use the fan blades of the Computer/ CPU fans for EDF, but since they are designed to be more efficient in low RPM, since they have more number of blades, which makes them inefficient at high RPM due to resistance and drag caused by the blades. Further fitting them and designing an EDF for them and fitting the blades in the EDF, designing a counter rotating static vanes if not very difficult makes you wonder, weather is it a wise course of action.

Is it worth the effort is debatable.

I have mounted one such vanes in an 73mm EDF. It gives good thrust but it is inefficient. I will post photographs subsequently.  


Title: Re: Computer Ducted Fan
Post by: Sumeet on May 10, 2011, 03:53:59 PM
I have also tried this few years ago but Didn't worked.  :banghead: You can't change that inbuilt motor to a newer heavy power motor coz, you can not at all.....  ;D

The reason is that In the Inbuilt motor of a CPU fan, Outer "can" a.k.a "Drum" or "whatever we say" has blades itself. There is no saperate
"Cans" or "Drums" for fan and Motor. The motor's "can" itself is the fan which rotates. So, its totally impossible to mount a new motor on place of older one without damaging either motor or fan...


But GUYS. keep pulling new ideas from our evil minds. So that we can try at home, when the study gets boring..... ;D

Thank you.

 :thumbsup:


Title: Re: Computer Ducted Fan
Post by: Snehal.Samar on May 10, 2011, 03:58:45 PM
hey, ;D
What i was thinking that just drilling a hole in the center of the fan and fitting it on a 2200 kv motor just like a prop.(I guess this should work ;D)
But it seems that the blades of computer fan are not efficient.??
So should i give up this idea??


Title: Re: Computer Ducted Fan
Post by: Sumeet on May 10, 2011, 04:00:33 PM
Hey another question. Since that inbuilt motor is brushless, Can we use our typical ESC to control speed of fan? Well this don't make any sense coz they are not designed for the Aeromodelling applications but for other uses like Home made/DIY projects? What you say?


Title: Re: Computer Ducted Fan
Post by: Snehal.Samar on May 10, 2011, 04:05:57 PM
@Sumit.The motherboard itself is its ESC .hehe.It will work with ESC's but what rating??
It can be used as a table fan i guess;) .


Title: Re: Computer Ducted Fan
Post by: Sumeet on May 10, 2011, 04:07:00 PM
@snehal50samarpit

That will work but It also seems like the Pitch of its blades is far more greater to provide good cooling at low RPM's in the Computer. Give it a try if you have a "spare"/"Not in Use" motor. And also have some Multimeter near you to measure the Current draw in System.

Don't forget to tell us the result if you are trying.


Title: Re: Computer Ducted Fan
Post by: Sumeet on May 10, 2011, 04:08:57 PM
@Sumit.The motherboard itself is its ESC .hehe.It will work with ESC's but what rating??
It can be used as a table fan i guess;) .

That's what I was telling about the DIY or Homemade projects. Table fan is good. But as we don't know the Current, Can't tell you about the Rating of ESC.


Title: Re: Computer Ducted Fan
Post by: Sumeet on May 10, 2011, 04:14:09 PM
Ya and if you successfully run that fan with your motor, It could be also used as a Wind blower to dry the clothes in rainy season.  :giggle:
Sorry, Jokes apart, It could be used as a wind blower in a small scale Wind tunnel for testing our models and everything we make ourselves to fly. May be two three Fans together will work.
It is complicated but is a good thinking. What you say about a wind tunnel?


Title: Re: Computer Ducted Fan
Post by: Snehal.Samar on May 10, 2011, 04:14:58 PM
Yup i have a multimetre..i will try to post the results.But spare ducted fans is the problem.
It will be great if this experiment worked.
But iamahuman have already tried wid that .

@iamahuman . So you were unhappy with motor blades ...or the performance it was giving??


Title: Re: Computer Ducted Fan
Post by: Snehal.Samar on May 10, 2011, 04:20:22 PM
@ sumeet .Good imagination and full of creativity. ;)


Title: Re: Computer Ducted Fan
Post by: Sumeet on May 10, 2011, 04:20:32 PM
Hey such a thing also comes in the Hair Driers. And They rotate at a High speed too. Couldn't we try that one in our experiment?
And thanks for the compliment.  :thumbsup:

BTW You are creative too....


Title: Re: Computer Ducted Fan
Post by: Snehal.Samar on May 10, 2011, 04:23:35 PM
Hey dude this is an RCIndia website :giggle:

Well aprt from jokes we should try for it.I just saw some plans in www.mikeysrc.com and most of his model require a duct fan.


Title: Re: Computer Ducted Fan
Post by: ajith on May 10, 2011, 04:31:25 PM
i think  we can  use  the fan part from  Hairdryers   and  hot air blowers    as  they  are  suitable  for  higher  RPM .........
but  they  use  smaller Motors  in them .......


Title: Re: Computer Ducted Fan
Post by: Snehal.Samar on May 10, 2011, 04:36:25 PM
So what i am thinking is drilling a hole in the centre and throw away PC's fans motor or let it remain there.Then use it as a prop and fit it on the motor.
Motor mount for such a setup should not be a great deal.