Did you know that over 100,000 tape dispensers are disposed of annually? More than half of these dispensers go to waste because the tape core insert goes missing! Talk about wasteful. As a middle school teacher of almost 15 years, I can give a first hand account of such waste.

When my students build their paper roller coasters, they use quite a bit of tape. Often times, students will use the last bit of tape (a first for many of them), and throw away the plastic tape core. Unbeknownst to them, they also disposed of the core insert that holds the tape in the weighted dispenser and allows the tape to rotate freely from the roll. Here in lies the problem.

We have two choices... Educate the youth of America on tape roll inserts, add it to Common Core and test the \$h*t out of them so they understand, "Hey, this is an important part of the tape dispenser anatomy. I shouldn't throw this away", or prepare for the worst and teach students to use a 3-D printer so they can print you a new insert. Printing new tape core inserts will solve many of today's problems...

1. it keeps all of those tape dispensers from filling up our landfills
2. will prevent teachers from going over budget from having to purchase new tape dispensers
3. allows schools to invest in the latest 3-D printers with the savings mentioned in step 2
4. by some expert estimates, if every school and business across the country stopped excessive tape dispenser abuse, we can balance the National deficit within the next 5-10 years.

*my sources can not be verified.

## Step 1: Plan Your Design

First, measure the inside diameter of your tape core with a ruler or caliper. The tape core is 21 mm. In order to fit an equilateral triangle perfectly into the middle of a circle, it takes a level of math beyond my level of ability. But, I have a student who is a wizard when it comes to Google Sketch Up.

He was able to use Sketch Up to create a circle with a 21 mm diameter. Next, he made an equilateral triangle inside the circle. After a few prototypes, we discovered that in order for an equilateral triangle to fit inside the tape core, the distance from the base of the triangle to the apex needed to be 19.2 mm.

Using the push pull tool we adjusted the depth of the triangle to equal the width of the tape core.

Finally, he added the axles to the center of both ends of the tape core insert so that it can spin when fit into the dispenser.

## Step 3: Print the File

I've included both the .skp and .skl files.

## Step 4: Save the World!

Prevent our landfills from filling up with tape dispensers and their cores!

If you don't have access to a 3D printer, let me know and I could probably mail you a tape core insert. The file only took about 20 minutes to print.

It's nice to know that TerraCycle® and Scotch® Tape have partnered to create a free recycling program for tape dispensers and cores. Click on the link below for more details.

<p>You're right and you did a very nice instructable that also works for not American people.</p>
Thanks! I wish the US would convert to the metric system. It makes so much more sense.