30K RPM fan!

[Toysrme]

Exactly.

 

[FleshEating Bob]

Hmmm....

*Looks at Dremel*

I wonder if I have any spare fans...

 

[Toysrme]

Sigh... If you people actually want to play with power throw out the stupid dremels and crappy CPU fan's and grab a real ducted fan, motor and find something to safely power it...

You should be able to double the static thrust of a damned dremel and get a good deal more flow to boot eaily...

Atleast you would greatly negate it shattering in your face.

 

[FleshEating Bob]

Hey, dremel nothing, I've seen serious posts about building Gauss rifles here. This is not the type of place you find people with any concern for their own safety.

 

[schismspeak]

my dad works at b&d here in maryland. i showed him the picture and he got a kick out of it. he said with the weight and size of that "bit" youd be lucky to get 10k because the motor has barely any torque. it would create too much drag for the motor to handle. its built for speed not power. its cool though

with a dremel that statement is correct, maybe, but an rtx has quite a bit more torque than a dremel, I say the fan explodes @ 12-15k, that thread awhile back on the Overvolted case fans, the 80mm was spinning atleast @ 8k a dremel/RTX has much more torque than a case fan (@30v or not ) so your statment may be incorrect for both.

 

[KLowD9x]

My fan was at 35K and didnt explode.

 

[Avatar28]

Hey, I've seen a few things like a dremel, but much much larger. I don't know if they're quite 30k RPM but they should be pretty darned fast (no, it's not a rotozip, but is similar). Anyways, that would have the torque to spin a fan no problems.

 

[palee72]

I did something like this years ago, before I got into computers. I was building an RC boat from scratch. I needed a prop. I had an old hair dryer that died, but had this 7volt elect. motor. So I pop it on the shaft and it fit perfectly. So I figure, lets bump it up a notch. Well, I ended up running about 24 volts through this motor. I had it so the air was blowing over the motor.

I painted a little thing on the hub of the fan and was watching it go round and round.. (Don't know the RPMs, but know it was damn fast..)

Next thing I know, POW!!!!. It flew off and hit me in the nose. Felt like someone belted me. I feel down, and my nose is dripping blood. I sliced my nose open about an inch long.

I go upstairs to the bathroom, run cold water in a rag, all the time saying "Oh man, oh my god, oh, oh, oh..." and breathing heavy and all..

My mother comes to the door, knock, knock knock.. "you ok?", "Yeah, oh, oh god".. I can only imagine what she thought I was doing in there....

I should have had stitches.. but I healed and you can hardly see the scar.

 

[modenaf1]

I go upstairs to the bathroom, run cold water in a rag, all the time saying "Oh man, oh my god, oh, oh, oh..." and breathing heavy and all..

My mother comes to the door, knock, knock knock.. "you ok?", "Yeah, oh, oh god".. I can only imagine what she thought I was doing in there....

ROFLOL!!!

anyways, did it heal? do you have a huge scar there?

 

[Avatar28]

ROFLOL!!!

anyways, did it heal? do you have a huge scar there?

I should have had stitches.. but I healed and you can hardly see the scar.

 

[Toysrme]

My fan was at 35K and didnt explode.

You're forgetting that you don't "set the speed" at what you want and that's the end of it.

You varry the power to it and that's the end of it. All they did was stick a light disk on the first one off the line and noted the power it took to spin it at X RPM.

Then they just throw that sticker on the side of the control knobs.

*****They do not have the power to spin a fan half that fast

**********

If anyone wants to debate this fact further and would like to prove it, I'll be happy to stick THEIR OWN dremel on an R/C Test bench I have and check the RPM VIA TWO different tachometers and do the convertion and show the math.

Hell you can pick any design of dremel with any design fan blade you want...

Trim it down to whatever size you want... Grind the blades in half to whatever chrod you want...

You can cheat however you like.

The simple fact that within reason there is *NO* Way any dremel turning with an ill designed fan for high speed movement of air with that much drag on such a low powered motor is going to spin half that speed.

Any takers???

You pay shipping and send your own equipment. Digital photo's will be taken of both tachs.

Don't forget return postage, or it will not get home...

Hell for that matter I'll rig it up to include static thrust if you send me an extra $10 or more...

*edit*
Anything you send will not be paid for by myself it it expires or is damaged.

For an extra $60 I'll rig a fan onto a gow engine that can turn a 12" prop at over 17,000 RPM and tell you at exactly what point your fan explodes.

 

[Toysrme]

250w for a normal dremel... That wouldn't get close to 25K with a REAL ducted fan that's designed for that use in that size range...

 

[Caffinehog]

Toysrme is right. The RTX has no chance of spinning that at 30K RPM. Really it's probably more like 10K.

I just put it in the title because the tool is supposed to go up to 30K RPM. But as we all know, the tools slow down a lot when any work is being done with them. And even though the RTX is a lot more powerful than a dremel, it still can't even get close to 30K RPM.

Dremels come in 1A versions and 1.25A versions. The RTX is 2A.

Since W=V*A, then dremels put out 120W or 150W. That RTX does 240W.

 

[Caffinehog]

Took a whole ton of fan specs. I'm not sure how it applies to a dremel, but....
When I put them in excel, I came up with this:

RPM=1808.4W^0.5985

Now I KNOW from physics it's actually something to the .5 power.... SO.....
I get 2053W^.5 correct it to that type of equation.

So in THEORY, that dremel could turn the fan at about 21K RPM.

Except that it loses a LOT of heat... something like 20W at LEAST.

SO.....
more like 20K RPM.

Of course this is all theory. Frankly, I KNOW that the RTX runs at a MUCH lower tone with the fan on it... and it puts out a LOT more heat... Probably more like 80W. (Yes, even with the airflow and the internal fan, it gets REALLY hot after a while...) But even 26K RPM seems way out of line.

I'm sure there's a better way to test this.
But even typical scientific method says NO to 30K rpm. And real life observation says LESS.

 

[Toysrme]

Sorry about that msg blast again Caffinehog. I apparantly left out one word in a sentance like I said

Now if you want something powerful, you should pickup the highest of the high end and run about 1200+ watts through it on lion's.

 

[Caffinehog]

I don't hold grudges, Toysrme.



Heehee... Man, if you didn't know I was a nerd before, look at me!!! I'm doing equations! WHEEE!!!!! Lookie!!! I can figure the wattage of an 80mm fan by it's RPM's!

 

[Caffinehog]

Hmm... I wonder if that's useful?

For an 80mm fan, W = (RPM/2000)^2

 

[Toysrme]

That's ok...

Did you read the anti-TMD fan thread I drug out for two days and more than 30 posts???

I showed everyone the calculation for the speed of any point on a propellor at any RPM... Then proceeded to post on sevrial R/C engines which even I have to admit *MY* arguing skills would have bearly covered their relevance had it come up

THEN messed up an equation and fixed it before Science87 would have a chance to scroll by <Gee what is Toys ranting about... OOO OOO MATH!!! I WANT TO CHECK HIS MATH!!!>

Then I would have been smited down by Science87 because I messed up on BASIC MATH SKILLS and I would have had to quit the foums because my soul would have been forever stained...

I need another drink...

 

[modenaf1]

yep. or maybe you had too much to drink. no offense.

 

[Toysrme]

Why can't these idiotic therads just die before someone get's hurt?