Soldering on
Electronics work often involves connecting different components together to form an electrical connection, and there are a number of ways to do that. We’re all familiar with a very simple connection: wall plugs. A device that needs electricity in order to run needs an active electrical current, and if it doesn’t have its own power supply (like a battery or a car engine), it needs to connect to an external source. When you plug your vacuum cleaner into the wall, you temporarily connect the electrical innards of your vacuum with an electrical circuit that runs through the walls of your house.
The vacuum is a pretty simple case, because the only thing it needs from the electrical connection is power. Data can also be transferred through these connections. The cable that runs from the back of a desktop PC to the monitor uses the electricity to send data that the monitor can understand as instructions to display a certain pattern on the screen. Some cables can only send power, some can only send data, and some can do both. USB is an example of this last category.
The connections I’ve mentioned so far are all designed to be easily reversible. You push the plug into the socket, and it stays there until you pull it out. Maybe you use built-in screws to make it more secure. But the idea is that you want to be able to move a plug from one socket to another without too much bother. There are other connections that are more permanent, and that’s what I’m learning about right now. A central component of these connections is called solder.
Solder (pronounced “sodder” in the US) is a metal alloy that you can use to form secure electrical connections between pieces that start out separate. Solder conducts electricity, so if you have two wires and solder connects them, current can flow from one wire, through the solder, and into the second wire. Solder also has a relatively low melting point, only a few hundred degrees Celcius. It can be melted with hand tools, and applied to your components. This forms a solid connection, essentially making your wires into one connected piece.
Behold my very first soldering connection!
It is not great. It is exposed, and therefore not really safe. But it will conduct electricity from one wire into the other. Probably.
Solder itself is not entirely safe. It often contains lead, which is poisonous to humans when ingested. I’ve been using a Tin/Lead solder, so I’ve had to be careful to wash my hands before touching food or my face holes. But it’s hard! I’m touching my phone as I work on electronics, so I’m probably getting lead on it, and then I use my phone throughout the day. Is this safe? I’m not sure! 😬
Soldering: Day 2: Hup to, Solder!
On this day, I learned that soldering is hard, sometimes painful, and potentially expensive. I also learned that making mistakes can be fun!
I’m building a quadcopter drone first, before I even get started on the rocketdrone. There’s a lot that I don’t know about what goes into a drone, so it’s really hard to make informed design decisions about the rocket drone at this point. Like I discussed last time, you can split a problem up into separate components, and figure out how to solve problems more locally. I don’t want to be figuring out how drones work for the first time when I’m building the rocketdrone; that way leads to overwhelmedness and frustration.
The first not-just-practice things I tried to solder were two wires and an XT60 connector. This will help me connect the battery to the rest of the drone, which will let me power on components as I add them. This means that I can test the components right away, so I can see if I’m connecting things correctly.
The XT60 is a standard electrical connector often used in drones and other remote control products. I’m using it to plug the battery into the rest of the device.
And soldering it was hard. I was trying to get the wire to fit into a copper receptacle that wasn’t much bigger than the wire itself.
In order to make a connection, you usually want to apply solder to the two surfaces you’re trying to join (this is called “tinning” them), heat them both up so the solder melts, and then join them. The solder cools very quickly, so in seconds, you have a solid connection. To melt the solder I’d applied to the plug, I was sticking the soldering iron—a heated, pointed metal stick—into the wire receptacle. The video I watched made it look pretty easy. Unfortunately, it seems that copper conducts heat very well, and once of the things that was heating up was the plastic of the plug.
So the plastic kinda melted a bit, and the metal pin kinda moved a bit.
And this little Yossi went wee wee wee all the way to the hobby store to get new connectors. Which really wasn’t that bad!
Taking chances, making mistakes, getting messy
I had a conversation with my therapist the morning of the day I ended up trying to solder for the first time. He said that, if you’re trying to invent something, which I guess I am, there are going to be failures. You are going to break things. You’re often going to learn something when you break something, but it will be broken and you will need another one.
I’ve realized recently that, for all that I identify as a scientist (someone who doesn’t have any absolute, unshakable beliefs, someone who is willing to change their mind when they’re wrong, someone who treats mistakes as opportunities to learn something new), I hate making mistakes. I feel like I’m going to be found out to be a fraud, or it feels like I’ve proven that I’m not good at things and I’ll always fail. Growing up, I think I often felt like I was disappointing someone. And that reinforced to the point that I’m reluctant to try new things, because I might not do them well. I might mess up. The perfect becomes the enemy of the good, or the good enough, or even the better than before, and I just don’t try.
And yeah, I totally did make mistakes soldering. I ruined some of my hardware, and had to buy more. I burned myself a little, on the heated pins, on the soldering iron, and on tiny balls of melted solder. And you know what? It felt amazing. Trying something new, screwing up, knowing that I’ve just hit a little bump but damn it I’m going to overcome it, and then actually overcoming it, felt so good. I have been missing so much by playing it safe. From now on, I’m going to try things, and mess up, and keep trying. I’m going to learn, and improve, and it’s gonna be great.
So the next thing I did was give up and go home 🙃.
Getting by with a little help from my friends
I’m not always going to know how to make progress. In this case, I didn’t seem to be getting anywhere with soldering the wires to the XT60 connector. So I arranged to meet up with a friend who’d offered to help me learn various shop tools.
Having that help was a big asset. Sure, I was stalled for a couple days until we would meet up, but I wasn’t stalled due to uncertainty. I knew what the next step was, and waiting and being patient was actually part of the process.
It turns out that I hadn’t been tinning (pre-applying solder to) the soldering iron. When the heated, liquid solder on the soldering iron contacts the heated, but still solid, solder on the wire, the solid almost magically becomes liquid. This makes things so much easier.
After my friend’s help, I made much better progress. Take a look at this chip!
This is the power distribution board (PDB) for the drone. It takes power from the battery and supplies it to all of the components in the drone: the flight controller, the motors, and the cameras if present. You can see that I’ve successfully attached the wires to the yellow XT60 connector by now. Further, I’ve soldered the connector wires to the PDB. Note how I’ve tinned the pads of the board. See how the solder is only on those copper pads, and not on the black material surrounding the pads? I don’t know what this black material is, but it seems to repel the solder, which means that you don’t have to be as careful when applying the solder. What you want to avoid is the solder from one pad and wire coming into contact with another wire, or “bridging”. This can cause an electrical short. The solder-repelling material is a big help.
My next step is to connect one of the motors to the PDB and figure out how to activate it. I’ll have more on that soon!
