Left: Ceramic spindle bowl with divot; Right: Wooden, concave spindle bowl
Like with most of the topics we discuss, opinion is nine-tenths of the law. However, let’s talk a little about the physics behind what makes a good spindle bowl.
The bowls pictured are my two favorite spindle bowls. The ceramic, divot bowl is from Monger Ware Arts. The concave, wooden bowl is from Skaska Designs.
There are really three general styles of bowls that you’ll likely see: flat-bottomed bowls, concave bowls, and divot bowls. Naturally, there are bowls that fall in-between, as well.
Avoid Flat-Bottomed Bowls…
The point of a spindle bowl is two-fold. It contains the motion of your spindle so your spindle doesn’t end up halfway across the room. It also effects how your spindle spins. A flat-bottomed bowl has the greatest negative affect on spindle rotation. Because the surface is flat, the spindle will travel the full range of the bowl, losing energy quicker to forward momentum and possibly to bouncing off the sides of the bowl.
Divot Bowls…
Tahkli as sold by The Woolery.
Divot bowls have their place, but they also offer some challenges. These bowls have a smaller indent in the center of either a flat or concave bowl. The spindle tip stays in the divot as it spins. I like using a divot bowl with a sharply pointed spindle, like a tahkli or a clay bead spindle. This style of bowl contains the spindle almost too well and acts as a sharp contrast to the flat-bottomed bowl. With nowhere to go, the spindle tip bounces around the inside of the divot, creating drag on the spindle that slows it down. This is why spindles with a sharper, narrower tip tend to spin better in divot bowls. They create less drag than a thicker-tipped spindle, like a Russian-style spindle.
Concave Bowls…
From a physics point of view, the concave bowl with its smooth, round interior, provides the longest spin for your energy spent. Thanks to our friend, gravity, the spindle will automatically find the lowest part of the bowl and tends to stay there, minimizing forward momentum. The concave shape also prevents it from hitting the sides and creating drag. Where the divot has a sharper incline in a smaller space, the concave bowl has a more gradual incline which reduces drag.
Other Things…
While there are other considerations like material used and whether your bowl has a stem or not, the interior of the bowl will always have the biggest impact on how your spindle spins. Think about the types of spindles you use. Do your spindles have metal tips? If so, you probably don’t want a wooden bowl. Do you travel with your bowl? Ceramic bowls are more likely to break in transit. Whatever type of bowl you choose, choose the one you are most comfortable with and don’t be afraid to try different bowls.