Embedded within this project is actually a process that warrants it's own Instructable. That is "How to make custom patterns for a router using a laser cutter" covered in steps 1, 2 , 3 ,4 ,5 and 8. Look for that Instructable coming soon.
Note - this project details some basic wood working processes that require some previous wood working experience. To simplify this project once could easily just glue the coral onto the base using epoxy and use a bit of quarter round molding from Home Depot to make a well for the smaller earrings and thus avoid several of the more challenging wood working steps.
Step 1: Scan Coral
It's ok to leave the over open while you scan, it will still work fine.
Scan the image in greyscale and at a suitable resolution, like 300DPI.
Step 2: Adjust Brightness and Contrast in Photoshop
Try and get the image to be as crisp as possible so that the edge of the coral is clearly defined.
Step 3: Trace and Vectorize in Illustrator
Step 4: Calculate Offset
To know exactly where the bit land you need to calculate how much to offset the path in Illustrator so that the router will actually cut in the correct place.
Measure the diameter of the router bit.
Measure the diameter of the outside of the bushing.
Subtract the router bit diameter from the bushing diameter and divide by 2.
Offset = (D bushing - D router bit) / 2
Take this number and Path-->Offset in illustrator by this amount (plus a tenth of an inch for clearance purposes).
You should now see a larger path outside of your original path. Delete the original path, save the offset path as a file type that your laser cutter can read, in my case an .svg and send to the laser cutter.
Step 5: Laser Cut Pattern
Step 6: Route Rabbit in Base
Set up two stop blocks on the router table, plunge the wood onto the router bit and route a rabbit (woodworking term for groove) into the base along the front edge.
Drilling two holes that define the start and end of your rabbit using the drill press and a forstner bit is a good idea whenever you are routing a groove that doesn't pass completely through the piece of wood. The holes allow the router to have a starting point and make starting and ending your cut much easier - the router simply "connects the two dots" so to speak.
The width and depth of the rabbit is of course up to you. We chose 3/4" wide by about 1/4" deep. Make several passes so as not to remove too much material with any one pass on the router table. A feather board applying pressure down can help keep the board flat.
Step 7: Make Well for Studs
This was done using a large diameter forstner bit in the drill press and drilling down to the same level as the rabbit.
Step 8: Route Pattern Into Wood
Use painters tape to affix the acrylic pattern onto the base so it stays put and clamp the entire assembly down to the workbench.
Using the straight bit and pattern bushing that you previously based your calculations on plunge the router into the wood and follow the pattern. Make several strokes to remove all of the material.
Make shallow passes increasing in depth until you reach the depth cutout that you desire. The one below is around 3/16" - just deep enough to lock the coral in place.
Step 9: Sand
Use a thin wood block and a scrap of sand paper to get inside the recessed features.
Start with 120 and then finish with 220 grit paper.