A speed change auxiliary device of a lathe is provided. A side chamber of the lathe is provided with a shaft seat and a bottom shaft seat at the top and bottom thereof. An auxiliary device is provided between the shaft seat and the bottom shaft seat. The auxiliary device includes a shaft. A spring, an eccentric block, an engaging member, a positioning nut, a rotary sleeve and a fixing block are fitted on the shaft. The rotary sleeve includes a handle. Two sides of an inner circumferential surface of the rotary sleeve have protrusions. The protrusions each have an upright surface and an upper guide bevel at two sides thereof. The fixing block is disposed on the bottom shaft seat. Two sides of a circumferential surface of the fixing block have recesses. The recesses each have a stop surface and a lower guide bevel at two sides thereof.

The present invention surrounds a gouge for use in woodturning, particularly in the fabrication of wood bowls, wherein the gouge is configured to provide longer reach with decreased deflection. The decreased deflection allows safer and more efficient woodturning process, resulting in better quality woodturning products. The gouge includes an inner cutting profile which is offset upward from the center of the outer profile, thus providing more structural rigidity when extending the tool from a tool rest and into the concavity of a bowl being turned.