Building the cathode control boards

Post date: Dec 17, 2014 5:12:52 PM

As you may know from previous posts, there are lots of wires sticking out the bottom of the cube. By allowing electricity to flow through the 192 cathode wires and the 8 anode wires, the whole cube can be lit up. But to do this, I need to make a small circuit for each of those wires to support the lights. I have a bunch of solderable breadboards, called perf boards, that I will use to mount these circuits to.

I've never used perf boards before. It took about three days to get enough experience working with them to figure out how to use them and how to do it efficiently. One thing I learned quickly is that the copper pads around the holes will fall off if they are disturbed too much when heated.

Arranging the components and trying different ways to mount them was a learning experience. It is easier to connect two pads together with solder than to solder two wires onto one pad. It is not nearly as easy to bridge a gap with jumper wires when compared to having them right next to each other with solder trails. There is definitely a learning curve and they can be extremely frustrating when you don't have any experience. They can be way more compact than the solderless breadboards and definitely more permanent and durable. Nice, high quality wire cutters are a must-- spring action, sharp to the tip, cut in line up close with the lead. The snip is satisfying when you have used bad ones that don't fully cut all the way through.

There is so much technique involved with the soldering iron. Connecting the pads with solder trails is often tricky. The solder will flow down with gravity, so it sometimes helps to angle the board. Whether the tip is tinned or not makes a huge difference and often you need it tinned, but sometimes it is helpful that solder will not stick to an untinned iron. The shape of the iron tip is a big deal. Thin, to a point is nice, although the surface tension of the solder will often prevent it from staying on the tip. Untinned irons can corrode in the air. Because the pads are so close to each other it is easy to accidentally connect two, and difficult to separate them again without the right technique. The correct amount of solder is important too. When working with these boards, is is easy to see the difference between different brands of solder, and it is easier to work with thinner solder wire. The flux is a crucial element in this task. It is a chemical that is in the core of the solder that cleans the wires so the solder flows nicely. Lots of flux is helpful. I have also gotten to be able to use the surface tension of the molten solder to my advantage. When making longer solder trails, it helps to melt one part of the trail at a time, otherwise the whole thing might get stuck together in one glob. With all my soldering, I have run out of solder. I ordered some on ebay but I bought some more from a store because I couldn't wait.

l found I was getting a bit too much smoke in my face, so I got an old pc fan and figured out how to hook it up to a power supply. It does a really good job sucking the smoke away from me so I don't breath it in. The fan is also very effective at cooling the soldering iron when it is time to pack up my stuff.

Once I figured out how to use the perf boards and where to place the components, making the control boards went quite smoothly. Pictured below are a bunch of boards at different stages of the completion process.

-Jeremy