A LEGO Power Functions Creation

One of the Knights Of Bots members recently began to work with LEGO Power Functions (also referred to as LEGO PFs).  After about a week of experimenting, the member came up with a weird LEGO Power Functions contraption (shown below).

The contraption

A picture of it from the bottom

Here is a video of the contraption at work:

The contraption was inspired by a book titled, The LEGO Technic Idea book: Fantastic Contraptions, by Yoshihito Isogawa. This book is filled with pictures of fantastic LEGO contraptions (hence the title). Upon reviewing the book, we were inspired to try out some of his brilliant ideas. 

This creation/contraption is a combination of two of the gearing systems found in Isogawa's book. Both gearing systems are powered by a LEGO PF rechargeable battery. The first gearing system is very simple. It consists of an old LEGO Technic motor (Electric RC Race Buggy Motor 2002) which actually has two axle holes for turning attachments, a bevel gear with twelve teeth, and a double bevel gear with 20 teeth. The gears result in a spinning motion, as shown below. This system can be found in pages 52 and 53 of the book.

The second gearing system, in my opinion, is very interesting. It is powered by a LEGO Power Functions Medium-Motor. There are 3 double bevel gears with 20 teeth and one double bevel gear with 12 teeth.

 As shown in the video below, the motor spins the 12 tooth double bevel gear to mesh with the 20 tooth double bevel gear. As the motor changes directions, the double bevel gears shift in the corresponding direction. If the motor was spinning to the right, the double bevel gears would shift to the right, causing the two gears to mesh with the double bevel gear on the right. If the motor were to shift to the left, the two gears would shift to the left, causing the to gears to mesh with the double bevel gear on the left. This gearing system can be found on pages 148 and 149 of the book. This gearing shift is what makes this contraption unique.

Feel free to make the contraption described in this article. If you would like to purchase the LEGO Power Functions kit, the LEGO Technic motor, or Yoshihito Isogawa's book, the links are at the end of this post. The link for Isogawa's website is down below too.

LEGO Technic motor

Power Functions M-Motor

LEGO Power Functions Motor Set

Yoshihito Isogawa's book

Yoshihito Isogawa's website