If you like making jewelry and have some experience using the Othermill, then this is a great project for you! This style of necklace offers a wonderful way to get creative and artistic with double-sided machining on the Othermill.
This necklace has four LEDs on the back of the pendant, which provide a beautiful glow around the outline of the pendant and highlight the pattern on the front of the necklace by illuminating the etched traces. This Instructable gives you two design options: a blank, solid copper front, or a bird feather pattern on the front. Download the file in the next step.
For Halloween, we made a bat version of this necklace! Everything is the same except the shape of the board, so the instructions here apply to the bat as well as the hummingbird.
Please feel free to use this technique to design your own pendants by mixing and matching your favorite shapes with your favorite colored LEDs. If you do design your own unique necklace, please post pictures of your creation in the comments. All of us here at Other Machine Co. would love to see them!
Step 1: Tools & materials & files
You'll need the following for this project:
Step 2: Attach the bracket and your material to the Othermill bed
In order for the design on the front and back of the board to line up, we need to use the alignment bracket. It's included with the Othermill, as are three mounting screws and an allen wrench.
First, attach the alignment bracket to the bed using the screws and allen wrench.
In Otherplan, set up the bracket:
Attach your board to the bed with double-sided tape, making sure the bottom left corner aligns with the corner of the bracket. Use 3 - 4 long strips of tape - enough that most of the back of the board is covered, but without overlapping, as that would increase the height of the surface.
In Otherplan, set up your material:
Now that you've set up your material, right click it and select Align To > Bracket from the popup menu. This will align your virtual material and bracket, which will match up with the actual physical bracket and material.
Step 3: Import the design and choose tools and settings
Now it's time to import your design into Otherplan and configure the settings.
Decide if you want the bird feather design on the front of the pendant or if you'd prefer the solid copper front. They're both pretty awesome, but the feather design requires milling both sides of the board.
Step 4: Cutting on the Othermill
Now that you've attached your material, it's time to cut the design into the board and then cut the board out of the larger piece of FR-1. Since we're using two tools, Otherplan will cut the finest details with the smallest 1/64" tool, then the larger details with the larger 1/32" tool.
Click the Start Cutting button. The machine will begin milling the design. If there wasn't already a 1/64" tool loaded, it will take you through the process of inserting one before it starts milling.
Once it finishes the cuts with the 1/64", you'll be prompted to remove the 1/64" and insert the 1/32". Do so, and the machine will mill the rest of the design. If you wanted just the solid copper front, the machine will also cut the hummingbird shape out of the larger piece of FR-1.
Once the machine finishes, remove the FR-1 from the bed and remove the tape. If you chose the solid copper option, separate the pieces and skip to the next step. If you chose the feather pattern option, the board will still be a single piece. Do the following to mill the front side if you have chosen the feather pattern option:
Step 5: Adding light
Now that you've finished cutting the hummingbird circuitry, it's time to solder the electronics. You have four very tiny LEDs, a switch, and a battery clip that need to be soldered.
Be careful when opening the LEDs, as they are so light and tiny that they can easily be lost! It's best to work on a large, dark surface so you can keep track of them.
Soldering components this small is pretty challenging with a soldering iron and conventional solder, so we recommend using solder paste and a hot plate, heat gun, or small convection oven to melt it. You can also melt the paste with a soldering iron if you're nimble. This Instructable uses a hot plate because more people have hot plates than heat guns, but all methods are valid. I personally love heat guns.
Apply small dabs of solder paste to each pad on the circuit side of the board.
Using fine tweezers, pick up an LED and look at the bottom. You'll see a green line dividing the chip in half, and then another tiny green line protruding from the middle of the first line. This tiny line is pointing away from the positive side of the LED. The squares to the left and right of the circle on the board are for the positive contact of the battery, so if you follow the traces from there, you'll get to the first little square of each LED pad, which is the positive side. The positive ends of the LED (which the little green line is pointing away from) go to the positive pads. I've highlighted the positive pads on the diagram, and also on the picture of the LED.
Okay! You know where to place the LEDs and which way to orient them. Place them onto the dabs of solder and gently press them down.
Now for the battery clip. It has a plus (+) sign on the top. Make sure that the plus sign pointing up, so that it's closer to the top wing of the bird rather than its belly. Place it onto the solder pads and press down gently.
Lastly, the switch. It has little nubs on the bottom that need to be scraped off. Use your fingernail or a sharp knife. Then line the pins up with the solder pads ("4A" should be on the right) and press it down gently.
Now that you've placed all the components onto dabs of solder paste, it's time to melt the paste. Use either a hot plate at about 40% or 420 degrees F, a heat gun, or a small convection oven. If you have very steady hands, you can use a soldering iron with a fine tip. The key is to heat until the dabs of solder paste flash bright silver, then quickly remove the heat. They will slowly get lighter in color once you start heating them, but wait until they turn bright silver. If you're using a soldering iron, they flash silver almost immediately. If you're using a hot plate or oven, it takes a minute or two. A heat gun varies, but it's on the quicker side. Once all the dabs of solder have melted and turned silver, remove the heat and wait for the board to cool.
Put in a battery and flip the switch. Do the LEDs light up? If so, great job! If not, you'll have to do a little troubleshooting.
Once your board lights up, you're ready to add the chain and clasp.
Step 6: Chain and clasp
You've done the hard part. Now you need to attach the chain to the pendant and attach a clasp to the chain.
Grab your jump rings and use your pliers to twist the ends about 1/8" apart. Make sure you're twisting, so the ring still stays round. You don't want to pull the ring into a U.
Thread a ring through one end of the chain, and the other end through the hole in the eye or tail of the hummingbird. Now use your pliers and twist the ring closed. Do the same for the other ring.
Add a jump ring and the clasp to the other end of one of the chains, and add the remaining jump ring to the end of the other chain.
You're done! Enjoy your awesome necklace. It will last for about 24 hours of continuous use before you'll need to replace the battery.