Introduction: One Cut "Y"

About: The BYU Compliant Mechanisms Research Group (CMR) involves students and faculty who strive to make an impact by creating compliant mechanism theories and applications that are novel, used by others, and make a…

In this Instructable, you will be making a block "Y" with only 1 straight cut. This is known as one cut origami. One cut origami (also known as one-cut, fold-and-cut, and magic cut) is a form of origami where you fold up a piece of paper, make one straight cut, then unfold the paper. Mathematical researchers have shown that any set of straight lines on a paper can be cut using this technique (with no extra cuts). Although technically every set of straight lines is possible, patterns exist for a butterfly, swan, turtle, and all 26 letters of the alphabet.

A "Y" was chosen for BYU, or Brigham Young University. This pattern was created by the Compliant Mechanisms Research Group at BYU.

Here are the materials you will need for this Instructable:

  • The printed origami pattern (print the pdf attached below this step)
  • Scissors
  • A pen or pencil

Step 1: Fold in Half

Fold paper in half (hot-dog style) along the center line, as indicated.

Step 2: Pre-crease All Remaining Lines

Pre-crease all the remaining lines on the paper. Solid lines are mountain folds, dashed lines are valley folds (as shown in the bottom left picture). We find that it is easiest to fold all lines as mountain folds, then reverse the folds on dashed lines to create valley folds.

At the end your paper should look like the bottom right section of the image.

Step 3: Collapse All Folds

Simultaneously collapse all fold lines. Make sure you don't accidentally create new folds, as this will ruin the pattern. This should create one flat stack of paper.

We find it is easiest to do the top section, then the bottom section, then fold across the middle line (as shown in the picture).

Step 4: Cut Through All Layers From a to B, Then Unfold

Now cut through all layers from A to B. This should be one straight line (A and B should both be visible and their arrows should point the same direction). If not, you have done something wrong.

Then unfold the two remaining pieces. You should now have a block "Y" and a matching stencil. Congrats! :)