LEGO rack and pinion gears 2 - Mechanisms

Some of my favorite gears to play with in LEGO is rack and pinion gears. I guess I like watching the gears move from side to side.

This is what we're building today.

The pieces I'm going to use today:

I didn't have the pieces the book used, so I tried to use replacement pieces.

Pictured above are red and yellow flat pieces for the rack and pinion gears, 

but they didn't work out at the end. So, later on, 

you'll see orange pieces to make this mechanism work. 

Pictured here is size 5 gray stick piece. What you need is size 3 gray stick piece.

I thought I might have fun with a mini figure since my daughter enjoys collecting them so much.

These are the replacement pieces for the red and yellow piece pictured in the first photo.

The red and yellow pieces are pictured in the background.