Quieter hotend cooling fans?

Hi,

I recently managed to make my motors almost completly quiet. Now the loudest part is the hotend cooling fan.
I had played around with a 50mm fan and an adaptor that I regulated down to ca. 60% max speed with a small voltage regulator. That worked well and I never had issues with cooling but it still wasnt as quiet as I hoped.

Now hearing that the prusa mk3 is using brand noctua fans I thought again of the topic. In addition I changed my effector/hotend carriage that doesnt have enough space for my old solution.

So im wondering if someone has out some thought into and found maybe a good balance between bigger fans, slower rpm and noise.

Cheers

Noctua makes very quiet fans, but a 30 mm fan for an E3D hot end costs $15. You can run fans at lower than rated voltage and they will turn slower and run much quieter. Put a resistor or a few diodes in series with the fan to drop a few volts. Of course, you're gambling that the air flow is going to be sufficient to do the required cooling job. I believe the Noctua fans move less air than same size and same voltage rated fans, so you're gambling if you go that route, too.

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Ultra MegaMax Dominator 3D printer: [drmrehorst.blogspot.com]

Yeah, I saw some higher quality fans and there is a Noctua 40mm 12V for 12€ on amazon.
[www.amazon.de]

Now the question only is how much noise they really reduce.

I just measured with my phone and i get 40dcb, while noctua promises 17, that would actually be quiet good.

I also asked on the e3d forum about air flow volume, lets see if its comaprable.

Edited 1 time(s). Last edit at 09/27/2017 02:22PM by sungod3k.

I found this on the e3d wiki:

Quote
The use of the supplied 30mm fan and duct is highly recommended, the supplied fan has adequate airflow (4-5 CFM) and the duct is specifically designed to aim that airflow at the fins of the heatsink.

The noctua fan I was talking about has [noctua.at] has "Airflow 8,2 m³/h"
If I calculate that correctly

Amount : 5 cubic feet per minute (cu ft/min of flow rate)
Equals : 8.50 cubic meters per hour (m3/h / flow rate)

Which I would say is enough, but doesnt allow any further speed/noise reduction.

Edited 1 time(s). Last edit at 09/28/2017 12:30PM by sungod3k.

You can buy the 3 pin pwm controller they have single ones and fancy ones that do a few.
[www.ebay.co.uk]
i dont know if you could chain one or 2 to this and still use it. a bit pricey used to be a few quid.

Try a fan from a computer server. They are made for long life, usually move a lot of air and make a lot of noise, but running them slow cuts the noise.

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Ultra MegaMax Dominator 3D printer: [drmrehorst.blogspot.com]

I've suddenly taken an interest in this subject - my 40mm hot-end cooling fan had started to screech on start-up, probably due to an unlubricated sleeve bearing, so I replaced it with a ball-bearing one from E3D's on-line store. It certainly spins very fast and shifts a huge amount of air, but it is SO NOISY! It's not the fan's motor, it's just the air rushing through its blades & frame.

I've currently working out whether I have enough room to fit a snail blower to the X-Y carriage, without it colliding with the frame of my CoreXY printer. It's going to be a tight squeeze...

A resistor or a few diodes in series will drop the fan's voltage and reduce the speed and noise level.

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Ultra MegaMax Dominator 3D printer: [drmrehorst.blogspot.com]

Toms 3d just released a QnA with e3d and here theyre talking about the 40mm fan https://youtu.be/7VudIDiXQaI?t=33m14s

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the_digital_dentist
A resistor or a few diodes in series will drop the fan's voltage and reduce the speed and noise level.

It would take quite a few diodes to drop the voltage enough to reduce the speed on a 24v fan!

I took the alternative approach - I peeled the label off the old fan that screeched on start-up and put a tiny drop of thin oil on the sleeve bearing. Seems to have cured the horrible noise for a while. I'm still going to investigate how I can use a 50mm radial blower fan in place of the axial one... quieter, and much better at forcing air into a restricted space.

I also considered once running both hotend and model cooling from two radian fans that would have been mounted above the carriage and pushed the air via hoses.
What stopped me was the fact that even the radial fans are still quite loud even when they dont have the high peak loudness of the axial onnes.

That said, I was looking for high quality radial fans to also quiet down the model cooling but it was much harder to find. I guess the case modding community doesnt really care about radial fans.

Edited 2 time(s). Last edit at 10/06/2017 01:33AM by sungod3k.

The fans in my delta printer became noisy several months ago. I replaced the original sleeve bearing fans with ball bearing fans, and they have been quiet ever since.

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Large delta printer [miscsolutions.wordpress.com], E3D tool changer, Robotdigg SCARA printer, Crane Quad and Ormerod

Disclosure: I design Duet electronics and work on RepRapFirmware, [duet3d.com].

In my case, the replacement fan was a ball-bearing type - the noise from the airflow was awful as the fan ran a lot faster than the old one!

A resistor or a few diodes will drop the voltage and slow it down a little, reducing the noise level.

Or for about $1 you can get a small buck converter to drop the voltage an adjustable amount and tweak it until you're happy with the noise level.

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Ultra MegaMax Dominator 3D printer: [drmrehorst.blogspot.com]

Fans are fans, the sizes and connectors are all standard. If you want something quiet just hop over to Amazon or Newegg and grab one. I put a very quiet 40mm fan on my Chimera, if you go up a fan size cooling will not be a problem - even the quietest 40mm fan moves much more air than a loud 30mm fan.



Quiet blower fans are harder to come across, I think the only option there is scaling down the voltage/duty cycle.

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691175002

glHjdJq.jpg

Wat U got there, some serious kit.

I ran across some Ebay deals several years ago and decided to try to build a printer from surplus linear stages. On paper I am capable of moving two direct drive extruders at >5,000mm/s2 and >500mm/s with "perfect" motion quality.

The whole concept is senseless overkill but it is also a ton of fun. I'm interested to see exactly what the speed/quality limits of FDM look like when motion is not a limiting factor.

[imgur.com]

At first it seemed like a straightforward project since the linear stages do most of the heavy lifting, but I ended up going overboard trying to build a frame/enclosure of matching quality so it has become a bit of a doozy.

Looks Good, (be even better if it could do some milling, probably pcb's no problem, but do you think it would cope with alu, it seems sealed enough.

Edited 1 time(s). Last edit at 10/06/2017 09:32PM by MechaBits.

Quote
the_digital_dentist
A resistor or a few diodes will drop the voltage and slow it down a little, reducing the noise level.

Or for about $1 you can get a small buck converter to drop the voltage an adjustable amount and tweak it until you're happy with the noise level.

As I'd said earlier - it would take quite a few diodes to drop the 24v enough to make a difference! I gave up after 5 diodes.

In the end I went for the second approach - I bought a couple of these for very little money. The description is rubbish - the regulator chip and the schottky diode are both rated at 3A not 5A - but I only need 100mA - 200mA so I don't care. Managed to drop the fan's wind roar to a gentle background whisper, while still getting a steady breeze behind the E3Dv6 cooling fins. I've printed a couple of test pieces with no sign of the filament jamming (though I haven't tried ABS yet).

Printed a simple little case for the board that bolted to the 2020 extrusion in a convenient place - nice.

Edited 1 time(s). Last edit at 10/22/2017 06:13AM by David J.