Making my own fume extractor - Page 1
Forum section: electronics / projects

author: Discotech
author_rank: Regular Contributor
timestamp: July 01, 2018, 01:51:37 pm
content: I did a recent upgrade on my gaming PC leaving me with some spare fans lying about so I figure instead of buying a fume extractor I'll build one myself, I've got a 200m fan that runs on max rpm @ DC12v/0.42A and a 140mm fan max @ DC12V/0.18AIn terms of powering them would I be better buying one of thesehttps://www.aliexpress.com/item/LED-transformer-5V-12V-24V-Switch-LED-Power-Supply-2A-3A-4A-5A-6A-10A-12A/32795332783.html?spm=a2g0s.8937460.0.0.77142e0eymKFVT(12v/1amp I was looking at) run through a pot to allow me to adjust speed or buying a 12v power adapter, stripping off the barrel connector and wiring it through a pot ?As for enclosure I was going to design and 3d Print one, I also have a switch I'd like to use and attach to the enclosure so I can turn if on/off at the unit rather than having to unplug which makes me favour the actual supply over the adapter and I've got thesehttps://www.aliexpress.com/item/2pcs-lot-Activated-Carbon-Filter-Sponge-for-Hakko-493-Solder-Smoke-Absorber-ESD-Fume-Extractor-13cm/32712020268.html?spm=a2g0s.9042311.0.0.27424c4d2dS4Ktto act as filters even though my soldering area is next to a windowShould do the job or is the power supply overkill ?

author: Audioguru
author_rank: Super Contributor
timestamp: July 01, 2018, 02:51:20 pm
content: Does your soldering iron get too hot so that it makes smoke? Then it is incinerating the rosin instead of simply melting it. Use a temperature controlled soldering iron instead and there will be an aroma of rosin, not smoke.

author: Discotech
author_rank: Regular Contributor
timestamp: July 01, 2018, 03:43:54 pm
content: Quote from: Audioguru on July 01, 2018, 02:51:20 pmI'm not sure how this relates to my question, but there is no smoke, my iron is temp controlled, it doesn't change my desire to have an extractor so let's keep to the questions I'm asking instead of trying to turn it into a debate over the value of having an extractor

author: helius
author_rank: Super Contributor
timestamp: July 01, 2018, 05:11:42 pm
content: Quote from: Discotech on July 01, 2018, 01:51:37 pmMore likely you will just burn up your potentiometer. They are not designed to pass amps of current.Either use a power supply with a control voltage, or a PWM circuit based on a 555 plus a mosfet.QuoteFans require higher starting currents than what is printed on the label. If the supply isn't adequate, they will stay locked.

author: Discotech
author_rank: Regular Contributor
timestamp: July 01, 2018, 06:14:43 pm
content: Quote from: helius on July 01, 2018, 05:11:42 pmI should have said pot + Lm317 sorry

author: JS
author_rank: Frequent Contributor
timestamp: July 01, 2018, 09:31:44 pm
content: PWM control is better, speed control will be more effective as the change with voltage will not behave ass well as with PWM and is more efficient as it doesn't need to heat the pass element to slow the fan. 555 timer could generate a PWM signal, you just need to feed that to a transistor and not much required, not like custom firmware µC or nothing fancy...JS

author: tooki
author_rank: Super Contributor
timestamp: July 02, 2018, 10:25:11 am
content: Quote from: Audioguru on July 01, 2018, 02:51:20 pmFlux fumes are harmful whether they’re smoke or not. Even more so from the fluxes for lead-free soldering.

author: JamesLerch
author_rank: Newbie
timestamp: July 04, 2018, 02:33:26 pm
content: I recently went down this path and built this 1.2 meter wide by 0.5 meter tall monstrosity:https://imgur.com/a/xHGC0SVThe whole thing hangs on the wall behind my workbench, about 300mm over the work surface. The filter elements are a sandwich of four 60cmx40CM (24" x 16" inch) HVAC filters from local hardware store with a layer of activated carbon filter between them.It works great but there was ONE error in design I hadn't considered. While the ten 100mm server fans move an insane volume of air, the 2.5M^2 surface area (48" x 16" inch) of the filter elements results in a VERY low air velocity. Net result the fume extractor didn't suck very well, and it should!I fixed the design by adding a front cover so it only pulls in air from the bottom of the extractor. With the front cover added the input air velocity went up and now I get a reasonable laminar horizontal airflow across the top of the workbench directly into the filter.Power is provided by an old PC power supply using the 5vdc output as a "Ground" and the positive supply being provided by the 12vdc rail for a working voltage of 7vdc, which is a reasonable balance between airflow and noise. I played around with creating a true variable speed controller but quickly realized Off/Low/High (7vdc vs 12vdc) complied with the "Keep It Simple Stupid" constraintThe need for the filter was my recent switch to Amtech Tacky Flux fromLouis Rossman's store. I never thought a flux would change the way I work, but it did, and everything gets flux now, I love this stuff, but it is REALLY smokey when in use!

author: Discotech
author_rank: Regular Contributor
timestamp: July 05, 2018, 08:22:26 pm
content: That's great! A little overkill for my needs as I don't have as much of a large space, I bet it's noisy though with those server fans

author: JamesLerch
author_rank: Newbie
timestamp: July 05, 2018, 09:08:22 pm
content: Measured next to the fan exhaust its 61 db on medium speed (7vdc), 70 dB on high (12vdc).The only mildly annoying aspect is a nearly inaudible 'beat' frequency that tricks my brain into hearing a song. The song is usually whatever Ear Worm Louis Rossman was humming on his most recent live stream

author: JS
author_rank: Frequent Contributor
timestamp: July 06, 2018, 03:24:48 am
content: Really nice! please change that cardboard with a wooden board and hang tools from it!Mine is a two PC fan food truck, with a narrow opening on the top, the roof flips up when working on small stuff and down for working with big stuff, pretty small and nice to work right next to it, doesn't cover much area but doesn't take much space either. I couldn't get an activated carbon filter but at least takes the fumes out of my face... I made it with a plastic sign I found on the street and some fans from old PC supplies.JS

author: georges80
author_rank: Frequent Contributor
timestamp: July 06, 2018, 03:35:58 am
content: Built and been using for a while now a fume extractor using large diameter locline material.Works great and easy to position. Not very noisy at all since the fan is at the 'exhaust' end.https://www.eevblog.com/forum/projects/diy-flux-fume-filter/msg636551/#msg636551cheers,george.

author: DaJMasta
author_rank: Super Contributor
timestamp: July 06, 2018, 05:16:33 am
content: The beats you're hearing is probably slight differences in fan speeds - when you have tones that are close together generated separately, you get resulting tones on either side (same way frequency mixing works in RF), and the way the math works out, you get a tone that's the frequency of the difference of your two tones - so if your fans run at 1000 and 1002RPM, you'll get a 2Hz 'tone', that if it's loud enough will be audible - you also get one at 2002Hz, but it doesn't sound like beats.Since you have them all mechanically coupled, this can be more noticeable because of the material and the direct vibration coupling between them, but with enough sound, it will be audible just over the air too.

author: exit_failure
author_rank: Regular Contributor
timestamp: July 06, 2018, 05:22:54 am
content: I built the same thing a couple of weeks ago out of scrap parts I had laying around. I'll post pictures and a description when I'm back home tonight.

author: JamesLerch
author_rank: Newbie
timestamp: July 06, 2018, 03:04:26 pm
content: Quote from: JS on July 06, 2018, 03:24:48 amYea, the cardboard went up as a test the day I hung the filter. I hate 'temporary' solutions that work as inevitably they end up as permanent solutionsI do have a sheet of Pegboard and materials to fabricate a proper cover, it is on my todo list.I used this cut to fitcarbon filter materialand while I tell myself I understand why activated carbon "Works" observing it in action still seems like magic! I watched an N-Channel FET release its magic smoke, but my brain refused to believe it since I couldn't smell the magic smoke. Very weird how we rely on our sense of smell to confirm suspicions.Quote from: georges80 on July 06, 2018, 03:35:58 amWhere did you find Locline of such proportions? All I could find readily was 1/2 or 3/4 inch versions. Any problems with Hot Air melting the inlet? I see Louis has this problem frequently, but well, its Louis and he's a little 'Cavalier' at times

author: georges80
author_rank: Frequent Contributor
timestamp: July 06, 2018, 03:39:40 pm
content: http://www.modularhose.com/Loc-Line-25-ID-System/is one source.Just search for 2.5 locline (or similar google-foo) since it is 2.5" diameter.I've been using my extractor VERY often. Had the system running for over 3 years now and NEVER had issues with heat. You would need to be purposely running very hot air (solder melting temps) directly at the plastic for an extended period of time - borderline stupid/on-purpose to damage it as in your picture.I use mine when desoldering/soldering by and and also with a small electric hotplate (chemistry isotemp unit) and when hot air reworking. Never ANY issue at all. So, as per above, I'd suggest the damage in the picture has been done by someone with less that stellar technique... like directing an oxyacet torch at it on purpose...cheers,george.

author: exit_failure
author_rank: Regular Contributor
timestamp: July 06, 2018, 08:27:52 pm
content: As promised, here's the ghetto fume extractor I built:So what I did was just take an old Sharkoon 80mm fan I had lying around. I drilled four holes through a piece of wood and attached the fan to it with zip ties. I used an old transformer based multi-voltage power supply. Its not the most efficient one but it has the big advantage of built in, on the fly voltage (and therefore fan-speed) control without using a pot. For this specific fan, 7.5V are plenty to suck away all the fumes from where I'm soldering and blowing them safely away to where I won't breathe them in any more.I'm thinking about buying a goose neck stand and maybe using a 140mm fan to make it more versatile and silent when working in enclosures and the like.

author: JamesLerch
author_rank: Newbie
timestamp: July 06, 2018, 08:41:29 pm
content: Quote from: georges80 on July 06, 2018, 03:39:40 pmThank you for that, I was googling for 3 to 4 inch results, no wonderIf I enclose the front and the bottom, I could use two or three inlets and run the fans at 5vdc where its very nearly silent.QuoteYou've never watched one of Louis's repair videos, he gets the job done and is entertaining.https://www.youtube.com/channel/UCl2mFZoRqjw_ELax4Yisf6wHis video's are what motivated me to not fear SMD and in hind site I've no idea why I held back. Its the same stuff, just smaller and honestly easier in most respects. I still dislike boards with inner layers and massive ground planes on both sides hiding the traces of interest in the middle.

author: Discotech
author_rank: Regular Contributor
timestamp: July 07, 2018, 05:16:17 pm
content: Quote from: exit_failure on July 06, 2018, 08:27:52 pmThis was an option I considered from some of the DIY jobs I'd found on the internet but I have pots, LM317's and I really wanted to use one of the IEC320 C14 switches I'd bought so I figured I'd learn more doing it this way, there's some nice 3d printer designs on thingiverse for enclosures but I'll have to modify them to allow me to house the switch and the 12v transformer I bought but it should be fun for a first project

author: SpencerTC
author_rank: Contributor
timestamp: July 10, 2018, 12:53:22 pm
content: TL;DRBut I am making a simple fume extractor right now too and found a nice articulating hose.I'll post a link to it in case it is something that might help you.https://www.amazon.com/gp/product/B00270GDB6/ref=ox_sc_act_title_7?smid=ATVPDKIKX0DER&psc=1If you don't want to click on a link search for ATVPDKIKX0DER in amazon.

author: georges80
author_rank: Frequent Contributor
timestamp: July 10, 2018, 05:24:12 pm
content: ^ yep, that locline 'hose' is exactly what I used in my extractor linked above.cheers,george.