All LEDs have a positive (+) and a negative (-) lead. As you can see in the picture, the positive (+) lead is longer than the negative (-) lead. You will always be bending the negative (-) lead. The official term for the negative lead is “cathode” and for the positive lead it is “anode.” For these directions we will use “short” and “long.”
This is an enlarged picture to show the use of the Helping Hands to hold your work.
ALWAYS FOLD DOWN THE NEGATIVE (-) SHORTER LEAD.
1) Start with the center hole. Fold down the negative (-) lead on the right side. 2) Place the second LED in as shown. Solder them together. Don’t worry about the end of the LED being too long. We will be trimming them. 3) Place the third LED in as shown. Solder them together. Continue on until all 9 LEDs are soldered together.
Before cutting the extra wire, take another look to make sure all your LEDs are going the correct way and you folded down the negative (-) lead in each case. This is the time to catch a mistake; you can always unsolder and fix it. Using your wire cutters, cut off the extra wire. Mostly these should be on the 4 corners.
You will need to take your wire strippers and strip off a bit of insulation at each end. You will be soldering the top and the bottom, so strip off enough to do so. You may also choose to strip off all the black insulation. Either way is fine.
You will need to cute each wire to fit. One goes on each level of the LEDs. So you will have a long, medium and a short one.
Look at your black wires. You need to solder each of them to the correct level. First look for the very first LED you put into the foam. This is the wire you will solder to the negative (-) leads. Solder your short black wire to the negative (-) lead of the LEDs on the bottom level.
Solder your medium black wire to the negative (-) lead of the LEDs on the second level. Solder your long black wire to the negative (-) lead of the LEDs on the top level.
I am 16 years old and I am a maker. I have made a air cannon that I got the opportunity to shoot with President Obama. I have also made two Arduino kits that are currently in the Maker Shed and they are called the 3x3x3 LED Cube Arduino shield and the SMD LED Arduino shield. I am currently working on 3D scanners.