The 'beater', 'tipper' or 'hammer' is the stick used to hit the bodhran while playing. It can be made out of virtually anything. Hardwood is often used because of its weight and durability. Any hardwood will do - I've seen maple, walnut and oak beaters. Softwood will work although it's lighter and will dent slightly if you like to tap the rim while playing. Most beaters are turned on a lathe, but you can hand carve one that will work just as well. Beaters are commonly six to eight inches long, but it's O.K. to experiment with length. Kevin Conneff, bodhran player for the Chieftains sometimes uses a really long beater (looks to be about 10-12 inches), while the bodhran player for 'Four Men & A Dog' uses a teeny, tiny beater (4-5 inches). Thickness can also vary quit a bit. I like a beater that is about 1/3rd of an inch in diameter where you hold it, but I've seen some fairly thick ones. If you're not fussy about looks, a piece of hardwood broomstick with the ends rounded and grips cut into it works great. I've also seen plastic beaters and I'm sure that an animal limb bone of the right size would serve the purpose as well. The most important thing to keep in mind when making a beater is to sand away any abrasive or sharp areas which could puncture or scratch the drum skin when playing. Some bodhran players forgo the use of a beater entirely and just hit the drum with the knuckles of their hand.