Introduction: 3D Printable Key Fob Bracelet

About: transdisciplinary artist / researcher in Baltimore MD

This is a flexible 3D printable bracelet you can make to keep a key fob accessible at all times. Follow the instructable to size a downloadable 3D model to your wrist, add any embellishments, and 3D print the bracelet.

Step 1: Make a Copy of the Bracelet File on Tinkercad to Be Sized for Your Wrist.

Go to the Tinkercad page for Customizable Openworks Fob Bracelet.

If you already have an account - log in and navigate back to the customizable bracelet file. Use the dropdown arrow next to the blue "Tinker This" button and select, "Duplicate and Tinker."

If you don't have an account, simply click the blue button that says, "Sign up to Copy."

Step 2: Size the Bracelet to Fit Your Wrist

Wrap a strip of paper, a string, or some other flexible material around your wrist to find a comfortable size. Use a ruler to measure the length of the string/paper-strip and convert the units to millimeters (you can just google ___ inches in millimeters).

In Tinkercad, with the bracelet selected, click the "Ungroup" button to break the model into 3 parts: the band, and the two end clasp parts. If you do not see the numbers, you'll need to drag the ruler from the right tool bar onto the work plane. Select the blue band, and enter the measurement you came up with into the lengthwise measurement -- hit enter.

Step 3: Position the Clasp Parts at the Ends of the Re-sized Band

After the band has been resized, the two clasp parts on either end might be out of place. Make sure these are positioned properly. By highlighting all the components and selecting the Adjust>Align tool located on the right side of the top tool bar. Once the align tool appears, you can select the middle dot at the end of the bracelet to align all parts along the lengthwise center axis.

Hint: if you want to add more design elements to the bracelet, the workplane tool can be used to place objects directly on the top surface of the bracelet. The top surface is the surface that will face outward when the bracelet is worn. To use the work-plane tool, look in the "Helpers" section of the tool pallet on the right side of the screen. Click the workplane button and then place it on the top surface of your model.

Step 4: Download the Modified Bracelet for 3D Printing

Once you've positioned the clasp parts at the ends of the band, highlight all the parts and click the group button.

Select the finished bracelet, then click, "Design" in the upper left hand corner, and select, "Download for 3D printing." In the pop up window, make sure you select the checkbox that says, "Download the selected shapes (1 shape selected)" and click the .STL button.

Step 5: Prepare You Model for 3D Printing in Cura

Once downloaded, you can open Cura and drag the downloaded .stl file into it. Position the bracelet on the printerbed, and make sure to select, "TPU 95A" as your material in the, "Nozzle and Material" dropdown menu located in the upper part of the right hand menu. Once you selected your print settings, you can insert an SD card into the computer's card reader and click the button in the lower right hand corner of Cura to save to the card.

Step 6: Print Your Model

Change your 3D printer's filament to the TPU filament. You will need to use custom settings for the printer-bed temperature, nozzle temp, and fan power. I was using an Ultimaker 2 extended+ -- so I went to Material>Settings>Customize and manually entered these settings: Nozzle temp 235C, Printer Bed Temp 70C, Fan speed 35%.

Now your model's ready to be printed