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kris

Acoustic decoupling: Rear Fan

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I would like to hear your opinion on the following idea:

My UM2 is not very noisy at all, but maybe I can make it even quieter? All I can hear is basically the rear fan. It does vibrate quite significantly, causing structure borne noise.

The fan is rigidly connected to the aluminium structure. And I noticed if I unscrew it and hold it in my hands there is no noise at all.

Silicon acoustic decouples can be purchased for larger fans, but I couldn't find any for the tiny rear fan. So I figure casting my own in silicon. The mold can be 3D printed.

Here is the virgin coupler:

decoupler 2

 

It is a bit shorter then the thickness of the fan, so it holds the fan in place with some tension.

 

decoupler 3

decoupler 1

 

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Awesome idea. Fan may move a little during fast travel speeds, but I wouldn't think it would be too bad. I've tried using rubber bushings, but I was still using screws to mount the fan, so improvement was not noticeable.

Let me know if you try this and get it working, cuz I'd sure like to get my machines to quiet down a bit (my older one is even a little louder now)

 

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There's quite little space for anything extra behind the print head - unless you adjust the home location by tweaking the micro switches. I would advise you to remove the white metal sheet which is covering the feeder stepper motor and one of gantry stepper motors. It's good riddance anyway - without it the stepper motors get better ventilated :)

I think the idea of the decouples is good. It might even help to improve the cooling of the print head, because the original mounting of the fan wastes some of the fan's capacity (by having aluminium blocks actually blocking the air flow).

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Did you move the rear fan in front or added another one?

 

I added another one - and inverted the air flow; here are more details:

 

http://umforum.ultimaker.com/index.php?/topic/6307-um2-twin-tornadoes/

I think I could further improve cooling (and reduce noise) by adding some spacers between the fans and the aluminium blocks they are attached to. First I need to understand what kind of changes need to be made to the extruder in order to solve the problems related to the PTFE isolator.

 

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There's quite little space for anything extra behind the print head - unless you adjust the home location by tweaking the micro switches. I would advise you to remove the white metal sheet which is covering the feeder stepper motor and one of gantry stepper motors. It's good riddance anyway - without it the stepper motors get better ventilated :)

 

I hope that is not a problem, at least I designed everything so that the rear fan does not extend over the rear of the extruder.

Here is the mold (ABS). No idea if this will ever work...but I guess it is worth a try.

2014 09 17 10.39.59

2014 09 17 10.40.44

2014 09 17 10.40.56

 

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My fine is basically silent. Someone else came over to my house and didn't believe me when I said it was on. He had to touch it. He has an UM2 and his is louder. If I turn off everything in the house (televisions, fans, dishwasher) and no cars are driving by outside and if I close all the windows (noisy birds and insects!) I can hear it from about 3 feet away. Any farther and the blood going through my ears drowns out the noise.

So...

If you can hear the fan at all then I consider it defective. We are talking about the "third fan". Behind the print head.

I recommend buying another one. Or remove the decal and add a drop of oil (I've done this to other fans but don't know if this trick works with this fan).

 

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Both my fans on my printers are pretty loud. I have them in their own room, and have to keep the door closed so I don't hear a constant buzz. I'm pretty sure the noise is created by the vibrations they create throughout the chassis of the printer as a whole, turning it into a little drum, or speaker, if you will.

Maybe the fans are not balanced... Maybe some people are lucky and get a more balanced fan than others... I dunno. For now.... I'll just keep the door closed :)

 

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I had 3 UM2's and the 3rd fan on _all_ of them was way more then just audible. I'd say gr5 is one of the few users with a silent fan...

I went on and replaced the fan with this one:

 

But I noticed that it gets louder over time. At first I couldn't hear it and now it is still quiet, but audible. Maybe the noise is caused due to thin strands of filament (aka. filament hair) getting stuck into it.

 

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Whilst I've been sorting out my UM2 issues, the fan was very loud indeed, so I bought a 25x25x10mm Sunon Maglev fan

and used m2.5 x 12mm cap head screws and used a dremel to take some excess bulk on the outside of the fan to make room for the hotend feed wires..

 

I will say it's much quieter, but not silent, although I am only 2 feet away from the printer, its very tolerable..

 

it stated 5m3 flow rate, and it certainly is pushing a nice amount of air through!

 

http://www.ebay.de/itm/Lufter-5V-0-43W-25x25x10mm-5m-h-16dBA-Sunon-MC25100V2-A99-/231085071506?pt=Geh%C3%A4use_L%C3%BCfter&hash=item35cdbe5c92

Mind you I've yet to print anything, so I'll see if anything is affected!

 

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I have no idea what the temperature back there is, but I guess it is pretty high due to the proximity of the nozzle. I am printing the mould for the silicon casting as we speak.

Sorry that I bump in a bit late. But those parts do not reach temperatures over 55C. The bottom part reaches about 50C when the nozzle is 220C. And the top is 42C then. In a default UM2 setup.

 

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