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A VERY strange mag-fan (Enlobal) experience

Posted: Sat Jul 22, 2006 1:29 pm
by Felger Carbon
The Enermax UC-12EB 120mm 1000RPM "Enlobal" fan:

Image

I used the two-thumb procedure in the Phoronix review to remove the fan assembly:

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The ring magnet dimensions are 2.5mm thick by 12mm high.

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This last photo is where it gets interesting. The "D" shows a foriegn object on the ring magnet. This proved removable. There's a gouge above "G". And the two "X"s call your attention to a neck in the center post, about 75% of the way down from the top. This neck obviously fits into the collet-like object in the center of the previous photo.

When I put the fan back together, I thought for a moment that the vibration had dropped a lot, but I was wrong. I spent an hour messing with the fan, trying different positions, flexing the fan case, even introducing an external magnet (which did influence the fan's rotation).

But mostly the story was the vibration, and the vibration coming and going. Setting the fan down on the table top was guaranteed to set off very audible vibrations as the fan apparently almost bounced up and down on the table!

Worse: as the vibration mode changed, the RPM changed! The worse the vibration, the slower the RPM. This sort of makes sense, the more vibration the more friction.

And compounding my frustration was the fact that the fan performed very well during the brief periods without vibration, only slightly louder than a Yate Loon at the same RPM.

I finally came to the conclusion that the fan was permanently unusable and hence suitable for some possibly destructive experimenting. For my first experiment, I decided to use 3in1 oil on that neck on the center spindle. I meant to only use a drop, but I guess it was a large drop - the oil flowed completely around the neck and down into the bottom. I turned the fan assembly upside down, hoping the excess would flow back onto the spindle. With nothing to lose, I refitted the fan assembly and tested the fan again.

The vibration was gone! Set the fan on the table, no vibration! The fan was now reliably quiet and constant-RPM... and still only a little noisier than the Yate Loon at the same RPM.

I think I'll give this a try as an exhaust fan, and see how long it takes for the oil treatment to wear off and the vibration to return. I had turned off the test setup while I typed this up, and when I turned it back on just now the vibration was still gone.

If you're a fan of fans, I recommend you give this fan a try. You should get $11 worth of entertainment from messing with it, and you might learn something that will benefit the SPCR community. :wink:

Posted: Sat Jul 22, 2006 7:51 pm
by dhanson865
Excellent post.

How did it get damaged? Did you get to use it much before the vibration started?

I was hoping these would be more durable and less troublesome than standard case fans but I'm not so sure now...

Posted: Sat Jul 22, 2006 8:46 pm
by Felger Carbon
dhanson865 wrote:How did it get damaged? Did you get to use it much before the vibration started?
During the manufacturing process, I guess. The vibration was immediately present right out of the box and never went away for as long as 30 seconds until I oiled it. I'm now using it as the exhaust fan in my #1 computer, and am (via the HDD SMART) keeping track of how many hours it runs before the vibration starts up again - if it does. :?

Posted: Sun Jul 23, 2006 1:52 pm
by Bluefront
I've taken two Globe fans apart (they had broken blades so were N/G). There was a small bit of a glue like substance on one side of the magnet area.....apparently acting like a wheel weight, to balance the blade assy. I'm not sure if this is a common procedure with different fan makers. But balancing a fan blade would be next to impossible for a normal user.....myself included. :(

Posted: Mon Jul 24, 2006 7:30 am
by NeilBlanchard
Hello Felger Carbon,

Unfortunately, the last image is the only one that is not showing up! :(

Posted: Mon Jul 24, 2006 8:08 am
by Felger Carbon
NeilBlanchard wrote:Unfortunately, the last image is the only one that is not showing up! :(
I checked, and you were right. Then I rebooted and the image was back! Obviously, you need to reboot. :D :D :D

Posted: Sun Jul 30, 2006 9:15 am
by nici
Balancing a fan blade should be doable. If you manage to get the blades off and then have a couple of needles at the center so it can rotate free. Then just use hot glue or something to balance it.. It would work at least in theory, but i've never had a fan with such terrible vibratonion i would have ha to try something like this... Another alternative would be to use a balancing thing meant for RC-plane propellers..

Posted: Mon Jul 31, 2006 9:44 pm
by DrCR
I have one of those magnet thingys that I use to balance my RC aircraft props. Does the trick, but fan balancing a 7blade case fan would get really hairy. Maybe something you would still want to play with if you like tinkering with fans though.

You can try the razor-blade type (Prather example) or magnet type (TopFlight example). Something like this can have too much friction.

If you have a couple of harddrive magnets around, you can pick up the TopFligt shaft and cones for rather cheap.

The problem with TopFlights setup: The long shaft can bend throwing any balancing way off.


DrCR

Re: A VERY strange mag-fan (Enlobal) experience

Posted: Wed Jul 08, 2009 4:46 pm
by Soul Shinobi
Felger Carbon wrote:I think I'll give this a try as an exhaust fan, and see how long it takes for the oil treatment to wear off and the vibration to return. I had turned off the test setup while I typed this up, and when I turned it back on just now the vibration was still gone.
So, uh, Felger Carbon, how's that fan doing? :D

Posted: Wed Jul 08, 2009 6:27 pm
by DrCR
Hey Soul. Welcome to SPCR!

Please note this thread is now about 3 years old. Not sure if Felger Carbon is even around anymore, but he still might get an email notification like I did.

Again, welcome to SPCR! Be sure to check out the sticky threads for some of what has already been talked about and assimilated and give an even closer look to the official articles. Have fun. :)

Posted: Wed Jul 08, 2009 6:30 pm
by Soul Shinobi
Thanks! I know I'm grave digging but I just had to ask for a follow up, I did so publicly because I'm sure I'm not the only one who's curious. This topic was referenced in an article of about the same age on SPCR, and the lack of a conclusion was killing me. :D

Re: A VERY strange mag-fan (Enlobal) experience

Posted: Wed Jul 08, 2009 7:48 pm
by josephclemente
Soul Shinobi wrote:So, uh, Felger Carbon, how's that fan doing? :D
Sadly, Felger Carbon passed away. :(
viewtopic.php?t=48920

Posted: Wed Jul 08, 2009 10:04 pm
by DrCR
Wow, I've been inactive in recent times to say the least, and noticed many of the old-timers have been as well, but I didn't realize Felger Carbon passed away.

I think this is the first time for me that a noted forum member on any of the forums I've participated in has died. :cry: