LED Cube: The case of the un-solderable iron wire
A little more than a month ago I failed soldering the iron wire for the first LED grid. At that time I didn't know what went wrong. Well, in the meantime I found out, adapted my approach and succeeded in soldering the first layer.
What went wrong? I purchased annealed iron wire instead of a plain (galvanized) one. Seems that I didn't recognize that there were two different kinds of iron wire available at the store and (of course) I picked the wrong one. Apparently solder does not stick to untreated annealed iron wire as the surface is pretty much fully oxidized so that solder doesn't stick without more aggressive solder aids like acidic solder flux. Annealing also makes the wire softer which I don't appreciate as the cube should be stable and sturdy. So the usage of plain galvanized iron wire is not only the solution to my soldering problems but also the preferrable solution anyway.
The difference of the wires is obvious once you know of the types. The annealed one is on the left:
 |
| From Building LED Cube |
Using the new iron wire the first layer was soldered together quickly
 |
| From Building LED Cube |
I haven't been honest in the beginning of this post. Meanwhile I not only soldered a single layer but all three layers of the 3x3x3 cube and put them together on the prototyping board. First tests in action were successful and promising. But more on that and why I doubt that I can build the 8x8x8 cube in the same procedure (horizontal layer by layer) next time.