Make sure to post pictures of your finished bullroarers!
Here are my answers to the Make-to-Learn contest questions:
What did I make?
A bullroarer! How they work: As they rotate around you, they also rotate on the string; this in turn vibrates the air, producing sound. Tools I used: a hatchet and mallet, drawknife, a hair-dryer, and my pocketknife. Materials: a piece of cedar, jute twine and some beeswax.
How did I make it?
I first learned of them when my assistant scoutmaster brought one of his to an event. I then decided to make one. I make them on my own. In this case I was making it for someone else, to be shaped similarly to one I had already made, so it stayed the same.
Where did I make it?
I made it at home in my garage workshop. I made this one for someone in my scout troop.
What did I learn?
I learned that I need to make future bullroarers heavier. There weren’t any challenges or surprises. I like the beeswax finish on the cedar wood. When I make another one, I will make it a bit heavier.
Step 1: Design
The design of the bullroarer is mostly a matter of taste. As far as I know, any shape will work as long as it's not too wide or heavy.
Here are a few links that provide some great information:
Step 2: Materials and Tools
Hatchet and mallet for splitting
Draw knife for rough shaping
Pocket knife for final shaping
Drill and bit for making the string hole
I typically use cedar because it is plentiful around my house, not to mention beautiful, but any type of wood will work.
About 5' of string
A finish of some sort
I use beeswax but you could use a finish of any type.
Step 3: Split
At the desired length of the finished bullroarer, plus some extra for wiggle room, saw to a depth of approximately 1/2"
(My saw cut was at 11.5" and my bullroarer had a finished length of 10.5").
Next, line up your hatchet on the end of the log with the bottom of the saw cut and pound it in with your mallet.
It should pop off with little effort and you should now have a piece that will be reasonably sized to shape.
Step 4: Shape
Just go at it! Make sure to pay attention to the grain as to not take off more than you wanted.
I used a draw knife up until the third picture and a pocket knife after that.
When you get it to the size and shape you want, you need to drill a hole for the string. The size of the hole doesn't matter, just as long as the string can pass through and leave enough wood to retain strength.
Now you should test it out to see if it's working how you want it to. If its too heavy it won't rotate on the string fast enough and therefore won't vibrate the air enough. if it's too light it won't create enough momentum and therefore will make it hard to keep going.
Step 5: Finishing Touches
Next you need to string it. On this one, I just looped it through the hole. Not essential, but I highly recommend a handle for the prevention of blisters. Experiment on the string length; find what is most comfortable to swing and put it there.
Step 6: Use
To get it whirling, you have to twist the string a good bit. Then, just give it a few feet of slack and spin it around, above your head.
The goal isn't to whip it around as fast as you can; spin just fast enough so that its outward momentum keeps it up.
If it still doesn't sound, try twisting the string more.