How Thick Should My Spindle Be for Bow Drill?

Spindle Material and Thickness

When choosing a spindle for your bow drill, consider the type of wood you’re using and the desired durability. A 1/4 inch to 1/2 inch (6-13 mm) spindle thickness is ideal as it provides enough strength for drilling without being too cumbersome. Thicker spindles can be difficult to rotate and may put too much pressure on the drill, while thinner spindles may break easily.

Spindle Size and Bow String Tension

The size of your spindle will also affect the tension of the bow string. A thicker spindle will require more bow string tension to rotate, while a thinner spindle will require less. If your bow string is too tight, it may be difficult to rotate the spindle, but if it’s too loose, the spindle may not be able to get enough grip on the drill. Experiment with different spindle sizes and bow string tensions to find the optimal combination for your bow drill.

Tips for Choosing the Right Spindle

When selecting a spindle, look for a straight-grained, dry piece of wood. Avoid using green wood, as it will be too soft and may not hold up well to the drilling process. Consider using a hardwood, such as ash or hickory, as it is more durable than softwoods. Additionally, try to find a piece of wood with a consistent diameter, as this will make it easier to rotate the spindle and maintain a consistent drill stroke.