Extruder fan specification ?  

Re: Extruder fan specification ?

Test results comparing the original Xinyujie xyj12b3010h fan to the double Jaycar YX2501fans, with and without speed limiting resistors in the cables:

Double-YX2501 with 10ohm resistor : Start cooldown at 2016-11-25, 0655
Start timer at 200C
Polymaker PC-Max white in printer
Ambient temp: 23.7 C . no enclosure.
Extruder temperature: 215
Bed temperature: 0
Extruder position: At top Centred over bed
Bed position: Centred
Temperature reached at time:
200C 0:00 m:s
150C 1:01
100C 2:37
50C not done

Repeat double-YX2501 with 10ohm resistor : Start cooldown at 2016-11-25, 0700
extrude a bit; Polymaker PC-Max white in printer
Start timer at 200C
Ambient temp: 23.7 C . no enclosure.
Extruder temperature: 215
Bed temperature: 0
Extruder position: At top Centred over bed
Bed position: Centred
Temperature reached at time:
200C 0:00 m:s
150C 1:02
100C 2:37
50C not observed but cooled down for fan resistor swap

Double-YX2501 no resistor : Start cooldown at 2016-11-25, 0725
sound louder and a much higher pitch
PC-max in extruder, extrude a bit
Start timer at 200C
Ambient temp: 24.0 C . no enclosure.
Extruder temperature: 215
Bed temperature: 0
Extruder position: At top Centred over bed
Bed position: Centred
Temperature reached at time:
200C 0:00 m:s
150C 0:50
100C 2:06
50C 4:49

Xinyujie xyj12b3010h, no resistor : Start cooldown at 2016-11-25, 0740hrs
PC-Max, extrude a bit.
Louder than double fan with resistor. Not as high pitches as double fan without resistor, but similar noise level. Video taken.
Start timer at 200C
Ambient temp: 24.3 C . no enclosure.
Extruder temperature: 215
Bed temperature: 0
Extruder position: At top Centred over bed
Bed position: Centred
Temperature reached at time:
200C 0:00 m:s
150C 0:47
100C 1:58
50C 4:29

Xinyujie xyj12b3010h with 10ohm resistor : Start cooldown at 2016-11-25, 0748hrs
PC-Max, extrude a bit.
Quieter. Video taken.
Start timer at 200C
Ambient temp: 24.3 C . no enclosure.
Extruder temperature: 215
Bed temperature: 0
Extruder position: At top Centred over bed
Bed position: Centred
Temperature reached at time:
200C 0:00 m:s
150C 0:54
100C 2:15
50C 5:12

Xinyujie xyj12b3010h with 12ohm resistor : Start cooldown at 2016-11-25, 0758hrs
PC-Max, extrude a bit.
Much quieter. Video taken.
Start timer at 200C
Ambient temp: 24.6 C . no enclosure.
Extruder temperature: 215
Bed temperature: 0
Extruder position: At top Centred over bed
Bed position: Centred
Temperature reached at time:
200C 0:00 m:s
150C 1:06
100C 2:47
50C 6:32

Re: Extruder fan specification ?

I recorded the noise produced by the fans with my mobile phone video app, from 30cm distance.

Then I replayed the recordings in 'loop mode' in VLC player in multiple windows, so I can switch between them fast and repeatedly to compare the noise subjectively.

Then play it back through active speaker system connected to laptop computer, much louder than the actual fans would be.

Listed in order from loudest to least loud:

1) Double-YX2501 with no resistor. This is very similar to the noise level produced by the Xinyujie xyj12b3010h with no resistor, but it has a higher whine to it, so I subjectively class it as louder, or at least, more annoying. But really, very similar from within a meter of the printer.

2) Xinyujie xyj12b3010h, no resistor: This one produces slightly better cooling with slightly less annoying noise levels. clearly the winner overall.

3) Xinyujie xyj12b3010h, 10ohm resistor: Noise noticeably reduced.

4) Double-YX2501 with 10ohm resistor: A little quieter than 3), also less annoying whine to to the noise.

5) Xinyujie xyj12b3010h, 10ohm resistor: Quite a bit quieter than 4).

My conclusions:

The double YX2501 from Jaycar is inferior to the original Xinyujie xyj12b3010h, but very close in cooling performance and noise levels. And, if you live in Australia, you can just walk into ta shop and buy a new one 7 days a week. No waiting for overseas delivery.

If you want lower noise, and you have already bought a Noctua fan, than ditch the Noctua fan and use the 10ohm and 12ohm resistor cables that came with the Noctua fan, but use them with the original fan. That way, you can easily switch between different cooling levels and noise levels, depending on circumstances.

The Xinyujie xyj12b3010h works with 10ohm and 12ohm resistors in series, the YX2501 from Jaycar does not start with the 12ohm resistor.

Therefore, the original Xinyujie xyj12b3010h offers the widest range of options: You can choose maximum cooling, as well as minimum noise production.

You could also try out a trimpot in series with the original fan. That would allow continuously variable speed and noise and cooling adjustment. In all likelihood, you could get the fan to spin and then dial up the resistance until it is near quiet and just about to stop spinning. It would not start with that resistance in series, but it will keep going.

Re: Extruder fan specification ?

Therefore, the original Xinyujie xyj12b3010h offers the widest range of options: You can choose maximum cooling, as well as minimum noise production.

Thanks for your research! While the data is still fresh in your mind, it would be great if you could create a bar chart for easy comparison.

Personally, I'm still concerned about swapping to anything that provides less cooling than the original fan. Melted parts could cause all sorts of issues, and if the melting happened slowly, over time it might be hard to recognize the source of the printing issues.

John

Re: Extruder fan specification ?

Therefore, the original Xinyujie xyj12b3010h offers the widest range of options: You can choose maximum cooling, as well as minimum noise production.

Thanks for your research! While the data is still fresh in your mind, it would be great if you could create a bar chart for easy comparison.

Personally, I'm still concerned about swapping to anything that provides less cooling than the original fan. Melted parts could cause all sorts of issues, and if the melting happened slowly, over time it might be hard to recognize the source of the printing issues.

While the fan is loud, the noise is not apparent if you leave the room. The loud noises from the movement of X and Y axis, on the other hand, carry well beyond the room with the printer.

John

Re: Extruder fan specification ?

What are you referring to with "10ohm" and "12ohm"? These?

BTW, i've tried the stock fan with the NA-RC11 (which is 98 ohm), it was dead silent but had the following performances. I'll try with a 50 ohm resistor and a 5mm spacer to add some distance between extruder and fan.

STOCK FAN
200 - 0:00
150 - 0:58
100 - 2.26
50 - 5:34

STOCK FAN + Noctua NA-RC11 (98ohm)
200 - 0:00
150 - 1:17
100 - 3:17
50 - 7:40


Re: Extruder fan specification ?

What are you referring to with "10ohm" and "12ohm"? These?

BTW, i've tried the stock fan with the NA-RC11 (which is 98 ohm), it was dead silent but had the following performances. I'll try with a 50 ohm resistor and a 5mm spacer to add some distance between extruder and fan.

STOCK FAN
200 - 0:00
150 - 0:58
100 - 2.26
50 - 5:34

STOCK FAN + Noctua NA-RC11 (98ohm)
200 - 0:00
150 - 1:17
100 - 3:17
50 - 7:40


Indeed, I made the wrong assumption that the numbers indicate the resistance in ohm. Thanks for pointing it out!

Re: Extruder fan specification ?

Reading here and there, I'm not sure about the approach used anymore.

Sorry if I'm going to overengineer a bit, but our requirements should be, in order of precedence:

Note that the point 1 comes directly from the E3D statement:
"An easy way to check that your heatsink has sufficient air flow is to simply feel the heatsink with a finger after a print has been running for some time. (Be careful not to touch the heater-block, it will burn you instantly) The entirety of the heatsink should be cool to the touch, including the bottom fins closest to the hot parts."

We shall then check the fins temperature, not the cooling time. A test could be to set nozzle temperature to 285° for 10 minutes and then check the fins temperature [unknown_value_2] (how?).

We shall then decide [unknown_value_1], by either asking e3d or deriving it from their statement "cool to the touch" - i would say a maximum temperature which grants the most sensible filament to keep its consistency (50°?).

At this point:
[*] we may discover that we already have a big safety margin, and may reduce stock fan with a resistor. I can say that with a 100ohm resistor is already dead silent.
[*] we may decide that we don't need a safety margin at 285°, but at - say - 220, because we only plan to use PLA. So we can add a bigger resistor, or use a lower end fan.
[*] etc.

In any case, i'm not confident with the Noctua solution, because we didn't test the proper things and consider the most important parameter (static pressure) in chosing it.

Applicable documents:
[Original E3D rationale for heater cooling] http://wiki.e3d-online.com/wiki/E3D-v6_Troubleshooting
[Original E3D assembly] http://wiki.e3d-online.com/wiki/E3D-v6_Assembly
[Original E3D fan duct] https://www.thingiverse.com/thing:340312

Re: Extruder fan specification ?

How are your findings with a 100ohm resistor using the stock fan?

Is it safe to touch at preheat 285 C?

My MK2 is still on backorder so i can't help out yet.

Re: Extruder fan specification ?

On a previous post I've reported the results of cooldown times with 100 ohm resistor; i think it's a bit too much, i'll try with 50 ohm.

But I think we've found a way to have a more reliable measurement of fan efficiency: add a temperature reading directly on the hotend fins.

So, USING STOCK FAN:
1) Connect a thermistor to the middle (T1) thermistor plug of the Mini Rambo (the one between yellow and green arrows).
2) Put the thermistor sensor between the fins (you can see them on the right side of the extruder).
3) Raise temperature to 285 for 10 minutes.
4) Check "Ex1" temperature value on Pronterface.
5) Now you have [unknown_value_2]!

Problem is... i don't have a spare thermistor right now.

Re: Extruder fan specification ?

Cool findings! really good idea

Re: Extruder fan specification ?

...
...

At this point:
[*] we may discover that we already have a big safety margin, and may reduce stock fan with a resistor. I can say that with a 100ohm resistor is already dead silent.
[*] we may decide that we don't need a safety margin at 285°, but at - say - 220, because we only plan to use PLA. So we can add a bigger resistor, or use a lower end fan.
[*] etc.

...

Very good and thorough approach to think this through!

But I wonder if it really matters which filament (and temperature) is used. The issue is that the filament might melt and then set again inside the teflon tube or the heat break. You need a temperature drop between hotend and heat sink, not a specific temperature. PLA will melt earlier than high temperature filaments, so there may not be any increased safety margin at lower temperatures.

Re: Extruder fan specification ?

You're right. We need to define temperatures drops.

BTW, i've found this very crap thermistor, and read it through my digital multimeter. I get very imprecise readings, but I can say with 215/55 (PLA default) i get:

STOCK FAN:
- fins temperature: 29°
- bed temperature: 36°

STOCK FAN + 100 Ohm resistor:
- fins temperature: 35°
- bed temperature: 36°

The thermistor is indeed off, but shoud still grant relative coherence, so i would say that with 100 ohm resistor added we're still below 55°. AND it's silent: the most noisy thing now is the nozzle fan. I'm now trying to keep the 100 ohm with some test prints and will report.

It is a very easy test; does somebody have a better thermistor or one of those laser remote thermometers and can replicate it?

Re: Extruder fan specification ?

I have a laser thermometer but it does not work on a shiny metal surface. It will measure the reflected IR light rather than the actual temperature.

Re: Extruder fan specification ?

ah, too bad, didn't know that. We have to rely on contact type thermometers then.

Is anybody equipped with a noctua fan able to measure fins temperature or at least the relative difference between bed (55) and fins?

Re: Extruder fan specification ?

BTW, i'm currently printing with the added 100ohm resistor, and it's working and silent.

I also think that there is a way to actually reduce the fan speed without that resistor; refer the following spec:

Both fans can be PWM controlled; the extruder fan can then be speed controlled as the nozzle fan. I have to see how (e.g. if a firmware mod is needed, or current fw commands for nozzle fan also work for extruder fan).

Re: Extruder fan specification ?

BTW, i'm currently printing with the added 100ohm resistor, and it's working and silent.

I also think that there is a way to actually reduce the fan speed without that resistor; refer the following spec:

Both fans can be PWM controlled; the extruder fan can then be speed controlled as the nozzle fan. I have to see how (e.g. if a firmware mod is needed, or current fw commands for nozzle fan also work for extruder fan).

Thank you Patrizio, I will try with 100 Ohms as soon as I have my kit.
Maybe Peter can help with G-Codes.

Re: Extruder fan specification ?

BTW, i'm currently printing with the added 100ohm resistor, and it's working and silent.

I also think that there is a way to actually reduce the fan speed without that resistor; refer the following spec:

Both fans can be PWM controlled; the extruder fan can then be speed controlled as the nozzle fan. I have to see how (e.g. if a firmware mod is needed, or current fw commands for nozzle fan also work for extruder fan).

There is a M42 command posted earlier in this thread that turns the extruder fan on and off via S0 and S255, so the speed can be controlled.

M42 P8 S255 = on
M42 P8 S0 = off

Re: Extruder fan specification ?

i completely missed those posts; anyway, the M42 command doesn't work as intended, it seems that a check happening every 2500ms brings the fan back to its intended speed.

I think that the only way is then to modify the #define EXTRUDER_AUTO_FAN_SPEED in the Configuration file (from 255 to a lower value) and re-compile the firmware. Indeed for some people this is more effort than fan replacement / resistor adding. I'll eventually do that, also to enable the M500 command.

Re: Extruder fan specification ?

i completely missed those posts; anyway, the M42 command doesn't work as intended, it seems that a check happening every 2500ms brings the fan back to its intended speed.

I think that the only way is then to modify the #define EXTRUDER_AUTO_FAN_SPEED in the Configuration file (from 255 to a lower value) and re-compile the firmware. Indeed for some people this is more effort than fan replacement / resistor adding. I'll eventually do that, also to enable the M500 command.

If nothing else, you can use the M42 command to find out what S value gives you the closest result to your 100 ohm resistor.

Re: Extruder fan specification ?

I've tried with some FW modifications.

The "EXTRUDER_AUTO_FAN_SPEED" define (default 255) can be set to 80-96 to have a good compromise between temperature and noise... But then the fan is controlled in PWM, and for any value you set beside 255 you'll get a high pitched coil wine. That coil whine is even more annoying than the fan itself... absurd. Back to 255 and 100 ohm resistor.

At least, you can set the PID values when you recompile the firmware, so you won't have to modify the startup scripts of your slicer.

I would say a 100ohm 2w resistor with JST plugs is a safe bet to reduce extruder fan noise without extruder-side modifications. Also, <1€.