Knocked together several different cheap Chinese PCB-plus-through-hole-parts electronics kits

Assembling some little solder-these-through-hole-components-to-this-labelled-PCB-to-make-X kits. Here's the byproduct: snipped excess lead wires.

Knocked together several different cheap Chinese PCB-plus-through-hole-parts electronics kits as a means of trying out a couple of different soldering iron tips, whilst listening to some recent podcast interviews with Harvard astrophysicist Avi Loeb. The surface of the yellow silicone mat on which I worked is speckled with tiny dried droplets of rosin and will get a quick wash later on, but small lengths of tape are an easy way to pick up the snipped-off leads of through-hole components.

This toy metal detector works reliably, beeping and lighting its LED when metal objects are brought within a few centimeters of the coil in the PCB. The PCB itself wasn’t horrible.

Kits like this provide a good opportunity to test out different styles of tip because they feature lots of different components arrayed across their PCBs, which makes their assembly quite different from soldering straight lengths of header pins onto IC breakout boards, for example. Some of the components have slightly different types of leads, like the flat, wider legs on the variable resistor or the thicker leads usually found on the buzzer in this “metal detector” kit.

Allegedly, a sound meter, but if you want to see those LEDs dance, however, you'll have to tap on the electret mic. — Allegedly, it’s a sound meter. If you want to see those LEDs dance, however, you’ll have to tap on the electret mic. The PCB features incredible disappearing solder pads.

Also, whilst some kits are perfectly fine, others can seem like case studies in corner-cutting and can-we-make-it-cheaper-ism, furnishing the low-to-middling-skilled soldering iron jockey with additional challenges. It may be the case that the PCBs are dirty enough that the plating around component holes won’t wet easily but the same plating is so whisper-thin that scuffing it up a bit with a fragment of Scotch-Brite hand pad or the tip of a fiberglass pencil is a dicey proposition. The leads on the components can be so thin and their appointed holes in the PCB so large, comparatively, that bridging the gap with solder alone is well-nigh impossible and you end up shimming the leads with … bits of other trimmed leads.

Yeah. The solder joints on those breakouts look pretty rough. In my defense, for what it’s worth, they all work (at the moment at least), I was trying out a new tip (Hakko T18-CF15), and I use lead-free solder.

My Hakko FX-888D came with a fairly large, blunt, pointed tip and it has served me well for years. Today, I gave two much smaller T18 tips a shot: the hyper-tapered, needle-like S4 and the chisel-ended CF15. The CF15 is still installed and it’s what I used to add the headers to these breakout boards.

If you’re interested in interstellar travel and the search for extraterrestrial civilizations, then these Avi Loeb interviews are well worth your time: Why The Universe May Be Full Of Alien Civilizations Featuring Dr. Avi Loeb (Sept. 20, 2018), Is ‘Oumuamua a Light Sail? Featuring Dr. Avi Loeb (Nov 9, 2018), and Finding Solutions to the Fermi Paradox with Harvard’s Dr. Avi Loeb (Feb. 2nd, posted several hours ago).