Here is a wooden ratchet noisemaker I made, also known as a "gragger" when used during the Jewish holiday of Purim. For mine, I used a few scrap pieces of 3/4 inch thick oak, a 1/2 inch wood dowel (less than 6 inches worth), a piece of 1 1/4 inch dowel for the handle (about 5 inches long), and some 3/16 inch dowel for the wooden pegs. I also used two 1 1/2 inch 8-32 machine screws with washers and bolts.
For tools, I used a table saw, a miter saw and a drill press.
Step 1: The Gear
I decided to make a gear with 8 teeth. I used a 2 1/4 inch hole saw to give myself a gear a little larger than 2 inches in diameter. First, I drew the pencil lines; it was easy to layout with a combination square. Then I ran the hole saw into the center of the pencil marks, just deep enough to mark out the circle. Now I can drill the smaller holes where the pencil lines cross the circle I just cut. For this gear, I used a 5/8 inch spade bit.
Now I can put the hole saw back on the drill press and finish cutting the circle. Perfect gear! Next, you need to enlarge the center hole to the size of the dowel that will be running through it.
Step 2: Attach the Gear to the Dowel
In order to keep the gear attached to the dowel, I placed a peg through the dowel and slid the gear over it. First, I drilled two holes in the gear. The holes were the same diameter as the peg I would use, and the depth I drilled was also the same as the diameter of the peg. You can see it in the first photograph.
Next, I chiseled the holes into a rectangle so the peg could slide into it. The second picture below shows what I'm talking about. The peg will determine where on the dowel your gear will sit, so measure carefully, than drill a hole the same diameter as your peg, and slide your peg through.
The last picture shows it all assembled. You can glue it together if you want, but when your noisemaker is fully assembled, the gear won't have any room to slide off the pin, so it's not necessary.
Step 3: Body and Handle
For the two side pieces, I decided they would be 10 inches long, and 1 inch wide, made out of 3/4 inch thick oak as well. I started with a piece around 2 1/4 inches wide, and drilled a hole through the end where the dowel holding the gear would pass through. Then, I ripped this piece into the two 1 inch side pieces. Doing it in this order enabled the hole for the dowel to be in the exact same place on both side pieces.
With a larger piece of dowel (around 1 1/4 diameter), I made a handle. I drilled a hole through the center which the smaller dowel could slide into. I then drilled a small hole through both pieces which I could slide another peg through to hold it all together. You can see it before it is assembled in the picture below.
Step 4: Stiff Board
For the stiff board, I ripped a thin section of oak on the table saw. Set your table saw so the thin piece is the cutoff so you don't have to place the rip fence right next to the blade. I found a ripped piece to be better than a piece resawn from the face or crosscut from the endgrain; both of these tend to split when bent and twisted.
I sandwiched the stiff board between two boards (about 3 1/2 inches long, and slightly less than 3/8 inch thick) and bolted the whole thing together. It's very similar to how a knife handle is held on. The width of these boards is slightly larger than the width of the stiff board or gear. This gives the gear a little bit of breathing room to spin freely.
You can then hold the whole thing together, and drill through the two sides and the middle piece and hold it together with the same wooden peg method we've been using. I kept my pegs toward the top, so the hole ran through only one of the sandwich pieces, rather than running through the stiff board.
I should mention that before making everything permanent, you should check the length of your stiff board. It should be short enough that it is not rubbing against the gear at its thinnest point. But it should be long enough that it slaps the next gear tooth after slipping off the previous one. Experiment a bit to find the optimum length for maximum slappage.
Step 5: Put It All Together and Give It a Spin!
With everything assembled, you can give it a spin and see how it works. For the moment, mine seems to hold together well without any glue. I like having the middle piece bolted together in case the stiff board ever cracks or breaks; then I can just unbolt it and put a new stiff board in. My noisemaker is fairly loud, and it spins freely in either direction. Have fun!