0
\$\begingroup\$

I have a 3D printer at home and looking to improve some parts.

The PSU on the printer has no labels so I'm not certain what it's doing - but the 3D printer's spec. sheet says it's 600W peak and it definitely puts out 24Vdc - so I'm assuming the PSU is a [rather noisy!] 24V 25A PSU.

So, as it's noisy and it's in my living room (the wife loves it, honest...) I'm looking to a) quieten it down and b) tweak it to improve it.

I've looked at getting this so as to get rid of the noisy PSU and maintain the 600W capacity.

Currently there are 2x 24V 0.15A fans connected directly to the PSU output but I have also bought 2 of these 12V 0.06A silent fans - the reviews are decent and I think they look pretty good, for what it's worth. I've snipped the signal wires and considered just putting them in series but thinking now I'd rather step the PSU output down to 12V then supply them in parallel / independently.

I've bought 2x of these terminal rails which I'm thinking I'll hook up to the supply and return from the PSU then I can just tag the 24V loads from there (to tidy things up somewhat as it's a complete mess at the moment.)

The controller board (here) is 24V and is supplied directly from the PSU output - it supplies the stepper motors directly from itself. The controller also controls a heated bed via a solid state relay which is hooked up on the power side directly to the PSU output- I don't know the rating for the heated bed this but is the beefiest component of them all.

Possibly I'll get another terminal rail and make it +12V via this 5A 24-12Vdc converter (60W), fed from the +24V rail - then I could supply the fans directly from this and simply take the fan returns back to the -24V rail. I'm unsure if this would be OK to do or if I'd need to have another rail with -12V? I'm just hoping that I won't blow the fans (as I already did with my attempt at connecting a LED strip - see next)

I also currently have a LED strip fed directly from the PSU but looking to switch that out for Philips Hue Lightstrip so I can switch it off if I like (during long prints the printer just sits there lighting the room at night.) I bought the Philips Hue Lightstrip Plus, cut the connector off which connects to the wall socket/ transformer and crimped some terminal rings to it then connected it to the PSU, but when I switched the printer on I heard a "puff" from the small electronic box and can smell something has burned up inside it. I'm unsure what's gone wrong here - I assumed the output from the PSU would've been fine to connect straight to the little module, as the wall-socket/transformer is rated at 24V 0.83A (20W) and the PSU output is 24V.

I assume the current has smashed it - but wondering how I could limit this so if I have a +24V rail being fed from the PSU I could then supply the Philips Hue Lightstrip Plus from it?

\$\endgroup\$
  • \$\begingroup\$ 3d printer in the living room? You might wish to consider possible risks to health. Google "Measuring and controlling emissions from polymer filament desktop 3D printers Prepared by the Health and Safety Executive" \$\endgroup\$ – Pzy Jun 20 at 20:50
0
\$\begingroup\$

I see this as a “mechanical” problem often faced by EE’s , that being the ambient noise of high velocity fans with Eddy current acoustic noise on the safety grids.

Techie details

But being EE’s we are much more familiar with Eddy current noise than ME’s. what you want is a longish laminar plenum tube (square or round) air exit and remove the safety grid wire layer that causes most of the acoustic white noise and whine from propeller/grid frequencies stimulated by the blade pulses going past it.

Construction

It could be a PVC pipe, the diameter of the fan and at least as long as the diameter, the longer the better but not so long as to cause standing wave bass frequencies.

Then you will have a whisper quiet fan at it’s no load ambient noise levels often rated in the -55dBc range. Mount the fans inside the square wood or round PVC with your ME 🎩 on, such that it is mid point of the laminar plenum and voila, your wife will kiss you. (Even more)

FWIW, Dell used inline plenum CPU fans over 20 yrs ago in their very silent forced air cooling towers for under the desk.

I cannot see your fan specs but it is air velocity that cools and not CFM but obviously they are related to load and diameter. You might be able to combine 1 bigger low RPM thick fan to replace 2 thin noisy high RPM fans if that results in the same flow or better air velocity inside.

Even a whisper-quiet fan is a misnomer when it is fastened next to a finger-safety grid. The Plenum only needs to prevent kids from poking their toys and fingers in it by the distance from the exit to blades and noise depends inversely with impedance mismatch interface gap.

\$\endgroup\$

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.