Got PC case Fans lying around?

[MavicFT1P]

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[davemgood]

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Very interesting. Wonder if some company makes a fan that rotates in the opposite direction? That way it wouldn't spin around if the fans were configured correctly - two clockwise and two counterclockwise.

 

[MavicFT1P]

Im guessing you would just flip one in each corner, to get the same effect.
Could prove tricky controlling the hover with 4 different fan knobs, but sure

 

[mrreddog]

Yea, give it a go, would love to see this thing take off......

 

[Thomas B]

Otherworldly!

 

[AMann]

Im guessing you would just flip one in each corner, to get the same effect.
Could prove tricky controlling the hover with 4 different fan knobs, but sure

8th grade science teacher giving you homework for tonight: Think about that for a moment and write why it would or why it wouldn't work. Hint: brushless computer fans don't run backwards by reversing polarity.

 

[MavicFT1P]

8th grade science teacher giving you homework for tonight: Think about that for a moment and write why it would or why it wouldn't work. Hint: brushless computer fans don't run backwards by reversing polarity.

For a fact, But the goal was to gain stability, yes?
So yes it would have half the power/torque of 4 CW props, but a better layout for a stable hover.
The adding, detracting of power to fans would have to fill in for there inability to reverse thrust.

 

[AMann]

For a fact, But the goal was to gain stability, yes?
So yes it would have half the power/torque of 4 CW props, but a better layout for a stable hover.
The adding, detracting of power to the fans would have to fill in for there inability to reverse thrust.

What happens with the two opposite thrust vectors?

 

[MavicFT1P]

They equalise.

This is a FRONT/BACK
BACK/FRONT layout you understand, same as mavic.

it's doing everything mavic can do, except reverse thrust, which it doesnt need to do to hover.

 

[MavicFT1P]

I think the idea that the drone was being controlled,/kept in a hover by 4 single fan control knobs adjusted as nessacery got lost along the way
I was trying to simplify the hover

edit: rereading the post, I see he meant/wanted a fan that could reverse rotation not thrust. I believe the day is yours Sir

 

[AMann]

You mentioned flipping two of them- with two thrusting downwards and two thrusting up, it will eqalize very well and stay parked on the ground.

Perhaps a 5th fan mounted as a vertical stabilizer like a conventional helicopter would work best.

 

[MavicFT1P]

You mentioned flipping two of them- with two thrusting downwards and two thrusting up, it will eqalize very well and stay parked on the ground.

Perhaps a 5th fan mounted as a vertical stabilizer like a conventional helicopter would work best.

As mentioned the idea is that the fans are Controllable! the Human via 4 knobs is the gimbal, so to speak.

The thrust up fans would be turned to max to lift it up. The Thrust down fans would simply be dialed to zero so not to oppose.
It would be a wobbly ascent no doubt, but once height is obtained, power is supplied to the Downthrust fans until an equilibrium/hover is attained.

My hope was that this would reduce the rotation seen in the video..
A 5th fan stacked horizontal to counter the rotation would work sure.

It's interesting how far you could take it as case fans come in all sizes
and could be stacked/slotted like lego.
Just need an onboard power source as in the video. We Should have a competition, hehe

 

[DanMan32]

Without reverse rotation still providing same thrust vector, it won't work. You'll either have counter thrust if all fans are providing thrust, or autorotation if you have thrust in only one direction by two fans.

Remember, in a quad, not only do you have counter rotation, the blades are curved the opposite way.

 

[mrreddog]

Use a 5th like a tail rotor...

 

[AMann]

Use a 5th like a tail rotor...

2 votes for this, yours and mine above^ . It would work well.

 

[DanMan32]

That's about the only way to prevent autorotation without opposing prop rotation and corresponding props.

 

[MavicFT1P]

That's about the only way to prevent autorotation without opposing prop rotation and corresponding props.

Agreed. So No brand make a case/CPU fan desisgn that can counterotate?

Sure theres no need for them to, but Id be interested what the obstacle to them doing so is?


Mine has the ceramic bearing type that eventually slow to a stop
from dust/gunk in them. Are they brushless?
You can peel the sticker and grease said bearing to get them going again, but there cheaper
to replace

 

[AMann]

Computer fans would be so inefficient for flight, they have a heavy frame. But worse yet, they are low volt fans. I thought it was pretty obvious in that demo that they were being overdriven and would have started smoking pretty soon if the flight hadn’t ended.