Medical instrument system comprising a surgical tool

A medical instrument system comprising:

• a surgical tool comprising:
• a tool shaft extending from a proximal shaft end to a distal shaft end,
• an effector at the distal shaft end,
• a first bearing fixed to the tool shaft between the distal shaft end and the proximal shaft end, and
• a coupling structure at the proximal shaft end;
• a handpiece comprising:
• a housing,
• a drive unit located in the housing, and
• a second bearing fixed to the housing;
• and
• wherein the surgical tool is repositionable between:
• a connected configuration in which the first bearing is positioned in rotatably supporting contact between the tool shaft and the housing, the second bearing is positioned in rotatably supporting contact between the housing and the tool shaft, and the coupling structure is rotationally fixed to the drive unit, and
• a disconnected configuration in which the surgical tool is separate from the handpiece,
• wherein the surgical tool is configured to be repositioned between the connected configuration and the disconnected configuration as a single integral unit while the handpiece remains as a single integral unit.