Introduction: Soldering Fume Extractor
I'm just getting into home projects, but after doing a few I decided breathing flux fumes probably wasn't too good for me or my kids. I could just buy one (prices range from ~$40 to well over $100), but decided to build my own. It ran a bit more than it probably needed too - I probably could have shaved a few bucks on some of the parts, but overall I probably came out a little ahead, and learned a bit in the process.
Parts list:
Project Box (8" x 6" x 3"); Radio Shack 270-1809 $6.99
DPDT Rocker Switch; Radio Shack 275-695 $3.99
Fan, 12VDC, 99CFM; Jameco 1585389 $11.95
Weller Fume Extractor Filters (3 pk); Jameco 684828 $7.15
Jack, DC power, Male 2.1mm; Jameco 151590 $1.19
12V Power Supply; Jameco 252823 $13.15
wire, nuts & bolts, solder, etc. I had lying around
total $44.42 (with two spare filters as well)
It works well, isn't too loud, and now I feel better about soldering.
Step 1: Prep the Project Box
Corner holes were marked by holding the fan on the outside and then using a very thin round file to mark the plastic.
I used a hand held drill with wood bits - seemed to do fine on the soft plastic. You can see that I roughed out where the center of the fan was because I didn't need holes there, although I clearly wasn't always too careful about where I drilled. In retrospect I think I should have cut a single large hole then used a wire blade-guard. That would have provided less resistance in the outlet. I used a deburring tool to clean up the edges. The switch and jack holes were made with larger drill bits - used a caliper to figure out the diameter of the shaft of each.
For the front hole I used one of the filters to pencil in the size, and then measures out a slightly smaller hole. I used a Dremel tool with a cutting wheel. It left a sloppy edge that I cleaned up with a razor-cutter and then a sanding drum on the Dremel. I used a punch to mark the holes for the wires pretty much by eyeball, and then used the wood bits again.
Step 2: Attach the Parts
All downhill from here. Turned out that the mounting holes for the fan were not exactly aligned, so I had to use the deburring tool on one of the top holes to get the bolts in.
Switch and jack each had a removable collar to secure them. I soldered extension wires to the jack and switch before mounting them so that I'd have an easier time making the necessary connections. Final wiring was tested by just twisting wires together before doing the final soldering.
I just used black copper wiring to attach the filter because I had a big spool of it. Originally I had planned to do a fancier bracket on the inside, but the realized the wire would block less of the airflow.
Step 3: Done
Screwed on the front panel of the project box with the included screws, and we're ready to go.
33 Comments
14 years ago on Introduction
One further suggestion to anyone who is thinking of building a fume extractor: use a 120V fan and skip the AC adapter. They're about the same price, but more powerful. Just be careful when you're working with that much voltage!
Reply 14 years ago on Introduction
the voltage doesn't matter, it's the current that's dangerous...
Reply 14 years ago on Introduction
Well, in this case 120V has enough oomph to push current through your heart, where 12V doesn't, except in some special circumstances (wet hands).
Reply 14 years ago on Introduction
uhhh, no, voltage doesn't matter, voltage is voltage... amps are current...
that's what can kill you...
Reply 14 years ago on Introduction
Yes, it's the current that will kill, but you need enough voltage to push the current through the resistance of your body. At a few thousand to a few hundred thousand ohms of resistance, your body does put up a bit of a fight. Just do the math: 12V divided by 10000 ohms is just 1.2mA, not enough to kill you. But increase the voltage to 120V with the same resistance and you're looking at 12mA, which IS enough to stop your heart.
Reply 13 years ago on Introduction
btw, this is off topic but who is that on your profile (pic)?
Reply 13 years ago on Introduction
Superteen extraordinaire!
Freakazoid! Freakazoid!
Reply 13 years ago on Introduction
knew he looked familiar.
Reply 14 years ago on Introduction
Why do people still argue about this today? (shakes head)... I thought myth-busters already "Debunked" this one for everyone.
Reply 14 years ago on Introduction
oh, i see, ok, sorry about that... ooohh, i'm so excited, i'm almost done with my DC to DC boost converter for my coil gun...
Reply 14 years ago on Introduction
or if you in Australia, 240v fan
Reply 14 years ago on Introduction
Thanks. I hadn't looked into that, but for now I feel better about lower voltage DC. (and I'll look out for used lamps) /K
14 years ago on Introduction
What would I need to do to add a fan speed switch to the Fume Extractor? My goal is to try and decrease the speed of the fan to lower the noise level and because I don't always need that much speed on little jobs.
Reply 13 years ago on Introduction
you could use a potentiometer
Reply 14 years ago on Introduction
Although the rheostat idea will apparently work, it looks like that at low speeds there can be problems. I came across another option - a pulse-width modulation (PWM) circuit here: http://www.bit-tech.net/modding/2001/12/03/pwm_fan_controller/1.
A similar circuit without the IC chip is here:http://www.solorb.com/elect/pwm/pwm1/.
Probably overkill for what you want, but thought I'd include the links for future reference.
/K
Reply 14 years ago on Introduction
I'm an electronics newbie, but I suspect you could put a rheostat in the circuit to do this. /K
Reply 14 years ago on Introduction
K, thanks. I'm really new at electronics. I'm not even sure how to wire this up without the speed switch. I can't tell where the wires are going from your picture. I'm trying to find somewhere on the internet that teaches me how to do it.
Reply 14 years ago on Introduction
The wiring for the fan is very basic - I've included a crude diagram. I'd have to look at some example circuits to figure out where to put the rheostat. /K
Reply 14 years ago on Introduction
Thank you. I got it working!
Reply 14 years ago on Introduction
Great! Let me know if you get the variable speed working. /K