Tip Magnetic Driving Fan II: An intriguing design

Slaugh · Post by **Slaugh** » Wed Sep 28, 2005 3:34 pm

I found this intriguing fan design while I was surfing the Internet. It's made by Y.S. Tech USA and it's called Tip Magnetic Driving Fan II. There's a PDF file available with some CFM, temperature and noise figures, but nothing about how they measured them.

[...] its patent impeller with diversion ring of T.M.D. FAN can divert the flow field to a specific direction and efficiently decrease the possibility of turbulence. It presents a 5% decrease in acoustic noise at a same flow rate comparing to traditional fan.

T.M.D. FAN reduces 75% of traditional motor hub area. This revolutionary breakthrough not only increases 30% of airflow and static pressure, but also brings the flow field directly to the centralized heat source. As a result, the thermal resistance (θ) of a Cooler with T.M.D. FAN is 8% less than with traditional axial fan.

Post by **NeilBlanchard** » Wed Sep 28, 2005 4:00 pm

Hello,

Even by their own numbers, this is a noisy fan: 39.2dBA!

Hardly a quiet fan...

Devonavar · Post by **Devonavar** » Wed Sep 28, 2005 4:23 pm

5% isn't much ... if it's accurate they must have done a LOT of sophisticated testing, since the average fan likely probably by almost that amount depending on voltage fluctuations, impedance etc.

weedow · Post by **weedow** » Wed Sep 28, 2005 4:29 pm

I have bin planing a simular fan, but this one is only the fanblades moving in free air (by magnetic forcefields) No bearing noise what so ever and no motor noise the only noise its going to make is the noise when pushing the air. Like the yapaneese subway/train (in tokyo or something i think) It might be a bit expensive thou and draw alot of elektricity.

Slaugh · Post by **Slaugh** » Wed Sep 28, 2005 4:46 pm

Yes, I saw this 39.2dBA in the specs, and you're right... this is really not quiet for a fan!... However, I saw many reviews where noise levels were badly reported because of poor testing methodology, and that's why I was wondering how they measured them. This concept is slightly new and will certainly improve... If other companies start investing in similar designs, maybe we'll end up with quiet fans with higher CFM in the future... For my part, I'll stay with Nexus until I find a better (quieter) solution...

mr_plow_king · Post by **mr_plow_king** » Wed Sep 28, 2005 4:59 pm

It certainly is noisy. It's not a new concept though, Vantec already had those for years with it's AeroFlow series:

Post by **Rusty075** » Wed Sep 28, 2005 5:12 pm

The fans on the Vantec Aeroflow are YSTech TMD I fans. Unless the TMD II's are much improved over the type I's I would steer clear of them.

It's an interesting fan, and it blows a lot of air anf undervolts well, but it's acoustic signature is just awful. Lots of pure high tones. It sounds like a tiny turbine engine spooling up.

One of the neat side effects of the TMD design is that with all that mass out of the edges spinning the fan has a strong gyroscopic effect that you can really feel when holding in your hand and moving around.

scotty6435 · Post by **scotty6435** » Sat Oct 08, 2005 9:53 am

Rusty075 wrote:The fans on the Vantec Aeroflow are YSTech TMD I fans. Unless the TMD II's are much improved over the type I's I would steer clear of them.

It's an interesting fan, and it blows a lot of air anf undervolts well, but it's acoustic signature is just awful. Lots of pure high tones. It sounds like a tiny turbine engine spooling up.

One of the neat side effects of the TMD design is that with all that mass out of the edges spinning the fan has a strong gyroscopic effect that you can really feel when holding in your hand and moving around.

Agreed. The fan is very impressive however it's far too loud for users of this forum. The airflow is very even from out to inside and the spin up noise is just so cool!

nutbar · Post by **nutbar** » Mon Oct 10, 2005 8:18 pm

I had one of these for a while on an older system. Before I started caring about the sound my PC emits. It wails a very hideous note. It sounds "neat" when spinning up or shutting off, but it's just so loud and whiney that it takes over the room while operating. Eventually one of the magnets in the ring became slightly dislodged and would hit something each revolution. With it turning twelve bazillion RPMs, that made a really aweful racket.

As their noise claims show, they have not improved it's noise level.

Gojira-X · Post by **Gojira-X** » Sun Oct 16, 2005 4:32 am

I have a TMD II fan on my Vantec, the fan is very load. The fan is also very sensitive to the level of the floor, if it isnt flat the fan will unbalance itself and make more noise. Differences in the torque of the holding crews also effect it, as so the fact that the coils are arround the screw holes. The Vantec VA4-C7040 has rubber washers reperating the fan screws from the TMD fan, but there is still a risk of shorting the fan out.

I am looking at replaceing this fan as ~38db on the first minute of startup is starting to get anoyoying, but I am considereing my options.

What doesnt help is the TMD II fans is a 74 mm fan, not a 70 or 80, which would be an easy replacement.

Gojira-X · Post by **Gojira-X** » Mon Oct 31, 2005 2:44 pm

Update: the TMD uses 70mm fan holes. I am nowing running it at ~10v via an Akasa Speed Reduction cable.
It aint quiet, but it doesn't case the case to resonate anymore. m
Maybe if i got off my arse and removed the front hdd cage, suspended my 2 hdds (the hitachi and a Nikimi 60gb) and got some sound dampening material, it would quieter.
Ho hum

Aris · Post by **Aris** » Mon Oct 31, 2005 3:00 pm

it would be interesting IF it was actually floating in a magnetic field and not physically attatched via bearings to the housing. the way it is now theirs little point to moving the moving parts away from the center of the fan. at such a small diameter, they arnt gaining hardly any more airflow at the center of the fan by removing the center hub where the hardware usually resides.

but if they would actually create a field for the fan to "Float" in without any physical connection to the housing, then this technique would be more usefull to us as noise would probably be near inaudible except for the sound of air being moved.

Post by **Rusty075** » Mon Oct 31, 2005 3:29 pm

I thought that exact same thing when I was playing with the TMD that I have. All it would take is some thoughtful reshaping of the stator magnets and rotor coils to produce. Then you could eliminate a major source of noise and vibration, and increase the MTBF.