This is a birthday card for my
brother.
You know how the Egyptians used to put arms and legs on things that do not have arms and legs? That is what I am doing here. I need the snake to offer cupcakes so I gave it human arms with cartoon hands. I figure if Egyptians could do it with serious art, then I can do it with silly cards.
The idea comes from the paper engineering of Bruce Foster in the Harry Potter pop-up book ISBN 978-1-60887-008-0. It is a secondary pop-up behind a flap on the last page (second to the last page, if you are counting pages as a regular book). The pop-up represents the basilisk in the movie.
I used this mechanism before, two crimps in a paper arm that extends from one side of the central fold to the other side that causes two discs attached to the crimps to rotate the discs a full 90°, which in pop-up terms is a very impressive movement indeed, although nothing actually pops up. In that earlier pop-up, the double mechanism was used to make it appear as if a dung beetle is pushing a ball of poo. The arms that connected the discs to the crimp were on opposite sides in corresponding opposite positions so the discs which were offset moved in the same direction
In the case of the snake, the discs are stacked and rotate in different directions, and the appearance of a snake slithering is arresting, because 90° + 90° = 180°, even though the movement is in opposite directions, like how a snake really looks when it moves. Unlike the previous dung beetle, the arms that connect the discs to the crimp are attached to the mirror opposite crimp, which causes opposite movement. It just goes to show the versatility of the awesome crimp, truly, a mechanism worth mastering.
Both arms start out hidden underneath the portion between the head and the coils. The cupcakes swing around with the movement of the turning discs, going from the 9:00 position to the 12:00 and 6:00 position respectively. In the original version, the two turning discs are reversed from this one. I did that on purpose because I wanted the tip of the tail to appear as if it is pulling into the coil. The original has it appear as if the the tip is being shoved out of the coil. That didn't seem right to me so I reversed them. Maybe a video would be better.
The top snake disc is glued directly to the arm that opens and shuts the crimp when the card is opened and shut, so that portion does move but only back and forth. It moves from 1/2" from the right side the card's central fold in the closed position, to 1/2" from the left side of the card's central fold when the card is fully opened. At that attachment is another mechanism for the snakes head. The head is a bit of origami. When the card is fully opened all the folds are flat. A crimp is formed when the card is closed. The bottom of the snake's head is attached to the crimp. The top of the snake's head is attached to the bottom as if it were a tent that is forced open and closed when the bottom is forced open and closed. So, crimp forces bottom of the head, bottom of the head forces top of the head.
Video ↓ shows card opening, closing, opening,closing, opening, closing, opening, closing, ...
You know how the Egyptians used to put arms and legs on things that do not have arms and legs? That is what I am doing here. I need the snake to offer cupcakes so I gave it human arms with cartoon hands. I figure if Egyptians could do it with serious art, then I can do it with silly cards.
The idea comes from the paper engineering of Bruce Foster in the Harry Potter pop-up book ISBN 978-1-60887-008-0. It is a secondary pop-up behind a flap on the last page (second to the last page, if you are counting pages as a regular book). The pop-up represents the basilisk in the movie.
I used this mechanism before, two crimps in a paper arm that extends from one side of the central fold to the other side that causes two discs attached to the crimps to rotate the discs a full 90°, which in pop-up terms is a very impressive movement indeed, although nothing actually pops up. In that earlier pop-up, the double mechanism was used to make it appear as if a dung beetle is pushing a ball of poo. The arms that connected the discs to the crimp were on opposite sides in corresponding opposite positions so the discs which were offset moved in the same direction
In the case of the snake, the discs are stacked and rotate in different directions, and the appearance of a snake slithering is arresting, because 90° + 90° = 180°, even though the movement is in opposite directions, like how a snake really looks when it moves. Unlike the previous dung beetle, the arms that connect the discs to the crimp are attached to the mirror opposite crimp, which causes opposite movement. It just goes to show the versatility of the awesome crimp, truly, a mechanism worth mastering.
Both arms start out hidden underneath the portion between the head and the coils. The cupcakes swing around with the movement of the turning discs, going from the 9:00 position to the 12:00 and 6:00 position respectively. In the original version, the two turning discs are reversed from this one. I did that on purpose because I wanted the tip of the tail to appear as if it is pulling into the coil. The original has it appear as if the the tip is being shoved out of the coil. That didn't seem right to me so I reversed them. Maybe a video would be better.
The top snake disc is glued directly to the arm that opens and shuts the crimp when the card is opened and shut, so that portion does move but only back and forth. It moves from 1/2" from the right side the card's central fold in the closed position, to 1/2" from the left side of the card's central fold when the card is fully opened. At that attachment is another mechanism for the snakes head. The head is a bit of origami. When the card is fully opened all the folds are flat. A crimp is formed when the card is closed. The bottom of the snake's head is attached to the crimp. The top of the snake's head is attached to the bottom as if it were a tent that is forced open and closed when the bottom is forced open and closed. So, crimp forces bottom of the head, bottom of the head forces top of the head.
Video ↓ shows card opening, closing, opening,closing, opening, closing, opening, closing, ...