I’ve just opened up my PSU. The 60mmx60mm fan in mine was a “D60SH-12B” 20CFM 31dB 4000RPM, I’m wondering if the 25x25 fan was to address the lower powered fans in some of the “Great Wall” PSUs, and if they are even necessary with the higher powered fans, unless it’s only there to stop the LED driver from overheating? I’ll be running tests
I think these would be the better fan to replace if the LED driver is fine and you have a “2404kl-04w-b30” fan in there, if the temps are higher than I’d like or it’s still too noisy after taking out the 25mmx25mm I’ll give a “GDT6015S12V2P2.54” a go, they look good on paper (a little too good).
Did you open up the front too? Just behind the front grill, there is a plastic (acting as a diffusor for the “fancy” light), which blocks over 95% of the air intake. Take it out and you can also take out the noisy backpanel fan, because now the bigger power supply fan (which is pretty quiet) can easily get all the air it wants. Keep the diffuser there and you really need the noisy little fan to suck out air from the box that is almost as air tight as a balloon.
If you like the light, you can replace the plastic air blocker with some white air filter. I found some leftover from the generic stuff you put over the air outlet of your vacuum cleaner. I split in half to make it thinner and printed a lighweight frame to hold it. I diffuses the light equally well, but lets the air through (and the power supply dust free as a bonus). In the end I took out the leds, its only two small screws and a plug. To me the constantly changing light was so annoying that the first thing I ever printed was a mount to hide the PSU under the table. Taking the leds out further improve air flow to the actual power unit fan.
To test the temperature without back fan and front blocker, I monitored the temp inside the PSU during a couple of large ABS jobs (A250 with nozzle at 260/bed at 90 deg). It never went above 37 deg Celsius inside the PSU box. A month later I made a small fan adapter and installed a silent 40x10 fan to be safe (or because I liked to tinker?). Anyway, after making the air inlet 1000% larger by throwing away the plastic, the small fan does not really need to do much compared to before. The bigger fan cools down the actual power unit, and the small one was probably only needed because they blocked the air intake to diffuse the stupid light.
As for the bigger fan on the power unit, I did not touch it. It is silent as it is and being inside the box blocks out sound even more. Yes, I can hear it when I stand next to the machine and turn it on, but a couple of steps further away it gets drowned by background noise, even when the snapmaker isn’t doing other noises. I think it is better to know that the fan is actually working than it to be completely silent, but that is of course only my opinion.
P.S. I really can’t understand the thinking behind the design here. They block the all important air flow to cool the power supply, just make a totally unnecessary, if not outright annoying, light for a stupid power supply!?! And in the process they have to make it awfully noisy. But yeah, we all like to spend our time watching a light go on and off and we can always cover our ears with headphones. Seriously, when I saw this, I lost any and all respect for the design of the snapmaker. This seems to be overpriced bling bling for fanbois, not a tool for makers.
Yes, them too, but if the air could move freely the small fan would not be needed, or at the most, very low revs would suffice (=practically silent). As it is now, it needs to work hard at very high revs, because there is only a very small air gap at the front of the box. It is easily fixed if you can live without the lights, otherwise you need something to partly block the very strong light (preferaly without blocking the air…).
Well, those capacitors don’t get warm at all, I’ve only seen them at 33 degree’s with ambient temps at 28 degrees. I have only been laser cutting though. As for the intake, I didn’t modify it at all I think it’s fine with volume of air able to get into the internal PSU, there is a noticeable amount of air being thrown out the back of the enclosure that isn’t getting warm. I’ll keep monitoring when I move into printing and CNC, the Hotend + Heatbed or CNC motor + Rotary module might draw enough to make things toasty, time will tell.
@kaitzu I’m not sure about your PSU as there seems to be some variants between them but mine has a cutout that is the same size as the shroud that the LED’s are mounted on, I wouldn’t expect removing it to help all that much in my case since the same volume of air needs to go through that shroud.
The airflow is limited by two narrow gaps, as you mention. The problem is not the 60mm fan, it seems to be able to pull plenty of air through the actual power supply. But removing the front plastic will have a very noticeable impact on getting air into the box. Just put your hand behind the PSU, both with and without the front plastic (and back fan) and you should notice.
The actual issue is getting the warm air out of the box. With only a small gap at the front, the back fan has to work incredibly hard to first suck fresh air into the box through that gap and then out again. Depending on your preferences and willingness to “mod”, there are several solutions. I’ll list some below:
“Simple fix” - for the practical type
Replace the 35mm fan with a silent 40x10mm fan. It will fit inside the box with a few mm to spare thickness wise, but you need to make a small adaptor to fit to old back plate holes. I made a 4mm thick plate with a large hole for the fan and small holes to take the screws from the back plate. On the other side it has 4 clip on pins for the fan. I made it out of stiff TPU, but PETG or ABS should work too. PLA can’t take any heat at all and is not suitable here. This alone, not only fixes most of the bad noice issue, but improves airflow as well. NOTE: a 40x20mm fan will NOT fit, this requires your own backplate, which there are plenty examples of on thingiverse.
“Functional improvement” - for the improve on everything type
If you want it to be really silent, take out the front plastic. The greatly improved air flow allows much lower revs get the air moving. Less revs= less noise. Adds more choices for silent fans as well, because now that air flows freely, much lower spec will be fine as they don’t need to handle (under)pressure, i.e. suck as hard.
2B. “Estehetic functional improvement” - for the style aware type
You can replace the plastic with a couple mm thick generic white air filter. I used the generic stuff that is used to filter the outcoming air from a basic vacuum cleaner and split it in half to make it thinner. It diffuses the light very well, in case you wish to leave them in place. Not only do you get better air flow, you reduce dust inside the PSU as well, without losing the light effect.
“Hard core mod” - you know for who
Like a racing car, throw all nonessential stuff away and put powerful stuff in: take out the plastic and the leds, put in the best possible 40x20 fan you can or can’t find. This fan is a bit too big, but that is easily fixed by printing your own back plate. Carbon fiber filament looks good.
“Snapmaker way” - for the rich and lazy
Buy the new power supply for 129€. You will get a shiny new box with a better 2€ fan and another 20€ “great wall” or similarly named power supply.
“The hard way” - as I do
Try out everything before you settle for what you believe is your optimal solution. Accounting for the time spent on reading forums, testing and trying out, it would have been much easier and cheaper to directly go for #4. But hey, we all have our own quirks. Which type are you?
Well I ran the PSU with no fan for 5 min, with an open case (Don’t try that at home sorta thing), just to find what was making the most heat, and it’s hands down the transformer at 42 degrees in 5 min. With the case all assembled and case closed up, 36 degrees after an hour of cutting, I honestly think it could just be the inconsistent fan from “Great Wall” that snap-maker was worried about, and only having a small area to work to compensate they put in a cheap jet engine to fix the problem.
The room temp here is 24 degrees, I’m sure as they considered world wide clients where ambient temps reach 55+ and 12 degree delta with a good fan only laser cutting. The lower CFM fan which could be in any of their PSU’s would probably be pretty toasty in those environments without assistance.
I am the “Hard Way” heck I’m looking into converting the laser from 1.6w to 5.5w XD
I successfully replaced the original back fan of the power unit (the original 2.0 version, not the updated revision) with one of those hydraulic fans:
Note: The wire order (black and red) has to be swapped for that fan.
Result: The noise changed from 74 dB in front of the illuminated side to 54 dB (in idle mode). Power unit does not feel hotter than before when 3D printing (with A350).
My bad. I thought they were talking about the fan for the enclosure. I believe the new update on the power unit is supposed to be more quite already. Is that because they changed out the fan type?
I don’t know the exact model of the power supply fan in the new unit, but from how they described it they talk mostly of only running at full power when needed and running at partial power or off when unneeded.
Speaking of which, the enclosure fan does support running and any commanded speed, although it requires gcode (in the terminal or in a file) as the touchscreen doesn’t support less than 100% speed (I think), though there’s not much motivation to run it as such as it renders the dust and smoke removal less effective.
Not sure if the filter module (way to expensive for me to consider) has any form of thermostat for the enclosure but one of the first mods I will be doing is to put an inline thermostat for the enclosure exhaust fan (should be easy) No touchscreen % control is lazy and a gcode step for our projects counter intuitive to both Luban being a starter or actually usable tool…
Hello, just purchased one secondhand A250 and new to this forum… OMG, noisy PSU fan. in reply to kaitzu above. well, fully agree the airflow is obstructed. Remove the big plastic diffusor in the front, exchange this with a filter mat that is usually included in the package when you buy new bags for your vacuum cleaner. AND remove the mesh between the FAN and the backplane. Of course for best result throw in another bigger fan. for mor information not how to do see Technical note from EBM Pabst… STANDARD, QUIET AND SUPER QUIET – THE MODELLING OF FLOW…
looking under “actual enclosure fan” (your post above) first alternative Review - installed with electrical clips in gel (so much easier - will take a photo if someone asks, push wires in and press down on the round bit), the fan is super quiet compared to the original one
heads up - label on the original fan is 0.25A, you say 0.23A
the second alternative enclosure fan is no longer available for sale (the guard was nice though
thanks for doing this and keeping it updated seeing it is an old post (you modified it 11 days ago).
it made it sooo much easier
Thanks a lot for this information! One question to all within the community: does anyone know how much current can be drawn out of the enclosure fan connection? I’d like to install a way heavier fan to maximize the suction effect. The fan I found will draw a current of around 1.67 A, so I suggest this is way more the control unit can output and I’ll need to connect a transistor stage or relais to the actual output.
If anyone knows the specs, this would be awesome! Thanks everyone in advance.
1.67amp on a fan? That’s some power for fume exhaust. I would do it through relay and have the fun supplied externally.
You might run into issues of bed adhesion and weirdness with prints with all the airflow. But I guess it would be great for lasering. Tho, it would have to have an air supply and a filter capable of accepting the air volume.
