The Muffin Fan! The Muffin Fan!

[MEXICOWANDERER]

Pathetic. I don't even know the right way to measure the mm size. Along the straight square edges the fan measures 60 mm square end-to-end all four sides on the Megawatt fan.

The label on the fan claims .19 amperes. Around a two watt draw. Brushless, no info therefore sleeve bearing.

How the hell can a .19 ampere (60) mm fan move any air? This too can be classified as pathetic. I chopped out the entire fan grille on both fans. Trashed.

Now what? Sikorsky grade 60 mm fans for each of the Megawatts? I've got very little room between the stacked Megawatts so a fat fan is not in the works.

Ninerbikes promised to post a raft of my images for an inside look at the Megawatt 400-watt model. There you can see why a fatter fan is improbable. Inductor, caps. transformers, and vertical ceramic resistors hog the vertical room inside.

This leaves me in the market for a "Sky Crane" grade of fan to replace the Chung King original. Brushless, ball bearings, and aggressive blade pitch rather than 10,000 RPM to move a lot of air. Db is worth zero. I could care less if the best fan is an 80 db fan. This is a battery charger not a pipe organ.

But I need help to find the best replacement fan. Everyone is paranoid about noise. I am paranoid about smoke.

It is a testament to the design of the Megawatt that those TO-247 bi-polar transistors can hold up with "virtually no heat sinking". If that Megawatt case is supposed to be an adequate heat sink, I am a penguin.

But that garbage-can fan has got to go! I need to order a pair of really really good fans. I am going to "carry on" with the heat sinking project. I don't even know if I measured those fans correctly.

Four liquid cooled heatsinks? This is a BORG cube, not the GLOMAR EXPLORER. I don't want US Customs pulling automatic weapons and flash bangs on me if I get secondaried.

I have no idea when NinerBikes is going to post that photo album. It might be a good idea to save it to disk.

Next up is a photo essay on how to solder 10-turn pot leads to the two teensy tabs on the original pot. With one hand. Meaning I have some tips and tricks up my sleeve that may make this a simple task for the timid. We'll wait and see. It costs a veritable fortune to text photo messages internationally for both sender and the recipient. And Niner cannot use WhatsApp.

[landyacht318]

It appears fans in the 60x10MM max out at around 21CFM, and it appears like megawatt installed one of the higher cfm fans, albeit a sleeve bearing and not Dual ball bearing.

http://partner.delta-corp.com/Products/FANUploads/Specification/EFB0612HHA-F00.pdf

http://www.digikey.com/product-detail/en/EFB0612HHA-F00/603-1406-ND/2560530


If the megawatt can handle a 15mm 70MM fan internally, this one is 37.5 cfm:

http://www.digikey.com/product-detail/en/AFB0712HHB-F00/AFB0712HHB-F00-ND/1927446

And this 70x15mm is 45.5cfm
http://www.digikey.com/product-detail/en/AFB0712VHB-F00/603-1806-ND/4376258

It appears all Delta fans are ball bearing fans, whether they are dual bb or not requires more delving.

Anyway, it seems that 10mm thick 60mm fans max out at 21cfm and 10mm more diameter and a 5mm more thickness will double that number, if they can be made to fit within the casing.


A previous post indicated you will have a powerful AC fan on the borg casing. Perhaps more ventilation holes drilled in the megawatt lids would be as effective.

[MEXICOWANDERER]

Landy MIL GRACIAS! I do not know about the 20mm diameter, 10mm radius clearance.

But I DO KNOW that circuit board is loaded with stuff that will go bump in the heat.

Proper air flow is magic. If noise is disregarded, even a hysterically laughable-size heat sink will become viable. The devices on it lose their inherent thermal design protection but you can't have everything.

If I must order fans I might as well order up a temperature alarm. Single sensor. Screamer piezo annunciator. Wonder what the max continuous temp rating is on those bi-polars? I could order a bag of tattletale thermal dots and play paste the dot on the heatsink if I could get junction and mounting pad thermal data?

Some of you may be wondering why I just don't Google Search. The RV.net site comes up more rapidly than Google or Microsoft. I don't know why. YouBoob is out of the question, I've waited 2-hours for 4 page PDF white papers to download. Serious downloads are a 150-mile round trip. When kids are out of school playing online games and listening to dog poop, the net plays it's role perfectly. Nothing gets through the net. ZERO is hardwired here - it's a 470 mile microwave link with drafting pencil bandwidth. SKYPE? Har har har. The home page won't even load. So forgive my seeming laziness at surfing the net. This is like surfing a pier.

[landyacht318]

Mex, unfortunately I am not finding any 60mm delta fans that are only 10mm thick. They do have a 38mm thick 60mm fan which moves 50 CFM and has a ridiculous static pressure rating, but I know that will not fit.

http://www.digikey.com/product-detail/en/FFB0612EHE/603-1040-ND/1014371

will keep looking and posting options.

Any thought about a larger fan 10Mm thick?

[Big_Katuna]

Have you measured any temperatures on the devices? Mostly rated for 90 degree C junction temps which is pretty hot. Too hot to touch.

Just a little air movement is needed to break up the laminar air flow.

[WyoTraveler]

That fan is approx 2 1/2 inches in dia. Since you said 2 watts assuming it is a 12 vdc fan. Of course the smaller the fan the more noise. When my computers die I never throw them away because they always have a good 12 volt supply and fan.

[MEXICOWANDERER]

The only thing those bushings not bearings fans are going to do is make a sudden left hook into a dumpster. Fan failure = smoke signal bankrupt sign.

"There! Alongside the tamales behind the straightened nails, is that a muffin fan I see?"

Eight bucks for BiPolar transistors, ninety dollars and a four hundred mile drive to the DHL office ain't gonna make it...

I have plenty of heat-sinking lined up here, ready to go. Forced draft cooling with Noctua fans too large to replace the Chung King's with...

I ain't gonna get an acute case of the stupids this late in the game.

[landyacht318]

Mex, I will find the highest 60mmx10MM dual ball bearing fan made for you and post back.

There might also be 80MM x 10mm fans available which will move more air.

The 0.19 rating might just be the start up surge. I've measured most of my fans against their rating, and most have to be up near 15 to 16 volts before they actually consume their rating. My 0.19 amp 60mm fan actually consumed 0.12amps at 12.8.

Back soon with the fans recommendations. they will likely be Delta brand.

Noctua fans are excellent, but designed to be as efficient as possible and quiet. Delta fans are all about maximum static pressure and cfm, I have a 252 cfm 120mm fan, and it is an absolute untamable beast. I use it as a blower in my workshop, instead of a broom.

[SteveAE]

I don't know what the power supply looks like, but if you have the room to add some aluminum cooling fins, perhaps your wimpy fans will do.

[westend]

I've heard that these Noctua fans are very good. I've had good luck with Panaflo, Antec, and Coolermaster fans.