I built a “Bubble wrap popper” with LEGO.
But this first version had a problem.

What’s the  problem…?

This is the first version. Sometimes popping goes wrong…

What’s the problem…?

The Problem is that:

The bubble is not always sliding to center of pressure foot (bubble press parts).

When the bubble wrap was sliding to the center of the pressure foot, it will crush precisely.
But when the bubble wrap was sliding to non-center of the pressure foot, it will not crush.

The problem’s cause is the bubble wrap sliding width.



The first one, the bubble will hit in the center of the pressure foot.

But when the bubble wrap become unable to sliding to center of pressure foot gradually, it will become unable to crush.

I took care of the problem!

An appropriate GEAR RATIO is needed to settle this problem.
So I made a “CVT (Continuously Variable Transmission)” to get an appropriate GEAR RATIO, and added it to the first version.

CVT generates a stepless gear ratio and to slides the bubble wrap to the center of the pressure foot.



 

Unit Test

I used the Cone Block.



The yellow cone can be moved back and forth, and adjusted a delicate rotation ratio.

 

Combined Test

By moving the cone, the rotation ratio and sliding width of bubble wrap could be adjusted.

 

Let’s Pop!

This movie’s background music is “Valse des fleurs” from The Nutcracker.
(I chose this because this machine cracks things!)



It’s not perfect but better than the previous version.
That’s one small improvement for this machine, one giant leap for mankind!

Thank you!