When turning bowls on a lathe, the speed at which you turn the bowl depends on several factors. The type of wood you are using, the size and shape of the bowl, and your own personal preferences all play a role in determining the ideal speed.
Generally speaking, hardwoods like maple or oak can be turned at higher speeds than softer woods like pine or poplar. This is because hardwoods are less likely to chip or tear out at high speeds. Softer woods, on the other hand, can be more difficult to control at high speeds and may require more careful turning to avoid damage.
The size and shape of the bowl also play a role in determining the best speed. Larger bowls may need to be turned more slowly to avoid tearing out the wood, while smaller bowls can be turned faster without risking damage. Shallow bowls can also be turned faster than deep bowls since there is less surface area in contact with the tool rest.
Ultimately, it's up to you to experiment with different speeds and find what works best for you and the materials you're working with. Start with lower speeds and work your way up until you find a comfortable range that gives you good results.