## Intro: 3D Printed Geometric Necklace

I am lucky enough to have access to a 3D printer. I wanted to use this to my advantage and create something I could show off and wear!

## Step 1: Drafting a Design

I used drafting paper, a compass, and protractor to draft my design. I started with a circle of diameter 5". I then bisected the circle to leave me with two equal halves. I bisected one hemisphere and marked the midpoint and connected the edges of hemisphere to the midpoint. I used the center of my circle to divide the hemisphere into ten 15 degree sectors and one 30 degree sector. I used lines and the midpoints of each segment to fill my necklace with triangles and a diamond. I have attached my sketch if you had trouble following my description.

## Step 2: Gathering Materials

modeling software / Google SketchUp 2015

3D printer / Makerbot

wire cutters, needle nose pliers

2 jump rings of 8mm gauge

metal chain (2 strands of desired length)

lobster clasp of 12 mm gauge

## Step 3: Create Your File

I am not very familiar with modeling software so I used Google SketchUp. You just as easily can make this design in Inventor or Rhino.

Step 1: Draw Your Circle

On the x y coordinate plane draw a circle with an origin at the intersection of the x and y axis. Bisect the circle with a diameter. Draw a radius to bisect the hemisphere. Connect the diameter to the midpoint of the bisect line.

Step 2: Guide Lines

Draw lines from the origin to the outer edge. The angle measures are ten angles of 15 degrees and one angle of 30 degrees. The 30 degree angle is the center most angle.

Step 3: Necklace Design

Delete the unneeded guide lines. Draw triangles from the radi lines to the midpoint of the next radi. The triangles of the left face right and the right side faces left.

Step 4: Inscribe the Triangles

Using the Offset tool inscribe the triangles 1/16".

Step 5: Deleting Unwanted Areas

Right click to delete the center triangles. If you skip this step your design will be a solid boomerang shape.

Step 6: Final Edits

Delete the middle lines. After deleting offset the outer edge 1/16".

Step 7: Extrude Your Model

Use the Push/Pull feature to extrude your necklace to the desired thickness (I chose 1/8").

Step 8: Extension Warehouse

The Makerbot works best using .STL files. In the Extension Warehouse I had to download a program to convert .SKP files to .STL files.

## Step 4: Printing

I have attached my .STL file. I encourage you to play with modeling software and create something that is your own.

## Step 5: Necklace Assembly

Step 1: Necklace Length

Decide where your necklace should lay. I made mine long enough to wear with a scarf.

Step 2: Cutting the Chain

Use the wire cutters to break a link in the chain.

Step 3: Adding Jump Rings + Start to Assemble

Open the jump ring and insert your chain inside. Then insert the necklace inside. Close the jump ring and repeat on the other side.

Step 4: Adding the Lobster Clasp

Open the jump ring and insert the lobster clasp inside. Close the jump ring and repeat on the other side with the hook.

## 2 Discussions

2 years ago

That would make for a pretty efficient bridge truss...

Sorry, future engineer speaking, can't keep myself from looking at technicity before beauty.

Your necklace is actually pretty nice, and would be wonderous with assorted earrings.

Reply 2 years ago

haha indeed it would make a nice bridge! thank you