http://youtu.be/buS14jK0n7g
Check out this video of the finished product.

Step 1: Concept

After finishing a few projects, I really wanted to build a little something for the kids to play with. The age difference will give this toy a different perspective for the kids. I expect the three year old to be intrigued by the mechanics and ability to make the worm move. And the one year old boy to use as a weapon and wreak havoc. Normal stuff.
This is not an original idea but I could not find any free plans on the line. I had seen one like this years ago in an antique store. The bad news is the box was closed so the mechanics were mostly magic. I'll include a pic that I used as inspiration.

Step 2: Materials

1-3' 1/4" dowel
1-3' 1/2" dowel
3/4" plywood piece
1•8 pine board

Tools
Miter saw
Hole saw
Drill
Biscuit joiner
Sanders
Paint
Drill press
Multiple clamps and piecemeal jigs

Step 3: Cutting Holes

I used a 2" holesaw. And a big half inch drill. In the end i only need 22 but I ended up needing more do to breaking a few
After cutting I rounded the corners to clean them all up.
Made a little jig to drill holes in the round part of the blank
Set each dowel to 2 1/2"

Step 4: Making the Cam Shaft and Box

This is the main part of the wiggle. After a lot of thought I decided to use a half inch shaft. Also to give the cam enough movement I would drill the center hole 3/4" from the outside of the circle.
Putting these on the shaft would be easier than I expected. After putting all my pieces on the shaft I lined them straight then made a straight line on the circles to give a reference point. Then turned each one about thirty degrees past the previous block. And I put a 10 penny masonry nail in between for a spacer.
Not too tuff.
The box is pretty straight forward.
Top 3 1/2"X14"
Sides. 3 1/2"X3 7/8"
Back. 4 5/8"X14"
Bottom 7 1/4"X14"
Used a biscuit joiner tool to make the butt joints strong enough to withstand some drops.
Before gluing it together make some holes. The eleven for the top will be from center out each way. Mine were 13/16" centers. These are pretty critical because this is where the worm rides up and down. The other holes you'll need are center of each side.

http://youtu.be/s8_OWOH3rQk
Little video of my first run.

Step 5: Put Together

Gluing the box together is a no brainier but I dry fit it together to check my biscuits, shaft alignment, and top hole placement.
Fingers crossed

And glue

Step 6: Finishing Touches

After first putting the "worm" together and running, it was very obvious that the dowel needed feet. These are 2"X1/2"X3/4" center drilled and glued(last).
Crank handle and end piece both same plywood as the circles.
The head and tail were made from a piece of black walnut that I shaped on a lathe in one piece then cut in half.

Step 7: Paint and Assembly

Had my little helper paint the "lollipops " and I painted the base. I didn't paint the inside because I love the look of the wooden mechanism.
Also the feet are the last thing you glue.

I hope this clearly shows how to build such. It has sparked my interest in wooden mechanical stuff. I love to hear comments and will answer any questions to the best of my abilities. I plan on entering the wood contest. Of coarse for prize but it would be nice to get the approval of "Ron Swanson".

Check out this video on YouTube:

http://youtu.be/buS14jK0n7g