The first thing I did was design the contraption. I knew I wanted decent filtering to cut down on the smoke, smell, and toxins emitted during soldering. They aren't totally necessary, but I don't want to be smelling toxic junk. Personal choice. I made a 3D model based on some set variables, like a ventilation motor I had lying around, cost, and this idea that I would make a light ring using a 555 timer.
I have a new reliable 3D printer, so the bulk of the custom parts will be made there. The print size is limited, so printing in PLA and using super glue will do fine for this application. ABS is another option, however.
The custom parts will consist of:
-Blower fan for the motor. This will have to be balanced later on to avoid vibrations.
-Funnel to help the blower pull in air from the filter box, instead of back in on itself.
-LED fixture to hold the 20 lights and electronics.
-Bracket for the hose to mount to the filter box.
-Another bracket for the hose, but with a grippy shape and space for the LED fixture to sit inside.
-Some clips to seat the hose on the arm, so the whole thing can maneuver around without a saggy hose.
There's some other stuff, but these are the 3D printed bits.
Since I knew the size of the parts, I ordered the hose, filter set, and a microphone stand/arm mechanism. In the meantime, I was able to work on the schematic for the LED chip. I googled "adjustable LED 555" and ended up with a screenshot someone made. In KiCad I translated it to get familiar with the inner workings. My version has two output transistors in case the LEDs I had were going to draw too much power. At least this way it'll last longer (turns out it is overkill).
Here's the final board layout. It's curved to fit the fixture, basically sitting inside, on top of the LEDs.
Aaaaaaaand here's the finished board with components mounted. It was bread-boarded before ordering the chips, so no worries there. Normally PCBs are 1.6mm by default, but because there won't be any stress on the board, I had it made .8mm thick with white solder mask. Didn't cost anything extra and thought it would help keep the board hidden in the translucent plastic fixture. Looks spiffy too!
Here's the board set in place with the adjustable potentiometer attached. The power rail is just a ring of solid Ethernet wire. Grounds are daisy chained. Replacing a light will be work, but not too bad. The board is over a layer of Kapton tape in case you were wondering. Silicon wire made the connections real easy.
Here's the body of the handle section. I laser cut a thin PETG face that would fit over the lights, and wedge in the LED fixture to the underside of the handle. This is the design to keep everything in place, while making it easily accessible in the future.
The filter box was totally going to be made out of wood, just like my previous one. However, I have an abundance of cardboard, and we're self isolating during the pandemic, so this is what I had on hand. The cardboard was still laser cut to avoid weakening the structure, as scissors might do. Everything fit together well. This filter system may be a bit much for solder fumes, but the idea is the air can move slowly through the filtration box, doing a more efficient job at scrubbing. The carbon filter uses those granules that don't fill up the entire space, so when this box is laying flat, the granules spread out and it has nice coverage. When building filters with carbon, I tend to stick the carbon before the HEPA filter because I have this weird idea that carbon dust will fly out. However, the air should be moving so slowly, it wouldn't really matter.
Finished box, minus the hose bracket that will go on top. In keeping with the cardboard aesthetic, I duct-taped the opening closed. Everywhere else has hot glue keeping it air tight, so it looks rather clean. You can't see the fan, but it's under the box, pulling air out and pushing it through those vents. I did double up the cardboard at the base, so the motor doesn't move around too much.
Lastly, here's the finished product in action. The arm holding the hose is just in view, and has no problem holding everything up. The ultimate test was to burn some flux and stick my nose near the filter output. Nothing but fresh air. Probably won't do that anymore, though.
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