Very Good effect to have. Easy to build, not too noisy, and could be used as a shelf for more props and effects.
Materials & Tools
Materials
Ice Cream Machine Motor
Boards for shelf and boards for cams
Books (I got mine at 2nd hand store for nickel a book)
Metal rod or dowel pin
2 yd elastic
(24) small eye bolts / screw type
Spray paint
JB Weld
Tools
Hands
Drill/Dremel Tool
Screwdriver
Saw
Scroll Saw
Step 1:
Once again we will use an ice cream motor. (gotta love ’em). If you are going to have a big book shelf like mine you need to use a metal rod because cammy dowel pin broke from all the torsion, but the wood will work well for a smaller shelf. Take the plastic lid thingy and JB Weld the rod vertically in the plastic hole. Let it set for at least 24 hours.
Take a piece of paper and draw a egg shape with the max reach of 4-4.5 inches from a center point for your cams. Now take the stencil, cut it out and draw the shape on one of your pieces of wood you are going to use as as your cams. I had nine cams and if I were you I might do five, nine was just too many going at once. Cut out your cams with a scroll saw and drill a hole the ends so it slips over the rod, stagger the cams and glue into place with liquid nails. Make sure the cams are randomly staggered. You can brace them into position with left over chunks of wood.
Step 2:
Pretty explanatory. The rest you can probably figure out from my pictures. In the picture below you can see little dashes on the back of the shelf, those are the eye hooks that the elastic runs through. They should be staggered between the cams and should be all equal in height. Then you go to your books, take a quarter inch drill bit, measure up from the bottom 2.5 in or whatever height you hooks are at, and up to the other one. Drill through, cut off the excess, and do for all the books that will move. Next take the elastic, tie it to the leftmost eye hook, run it through your book and back to the next eye hook, do the same with the other string. The string should be pulled fairly tight, but not too much, just enough to pull the book back. Once you have all of your books lined up over their respective cams, tie off the other end of the elastic to an eye hook and fill in with other books. Before that you my want to soap edges and stuff, that seemed to help a bit. run a staple in front of that books that don’t move so they don’t start walking away. Hopefully it should work! 🙂 Good Luck! and have fun!