A positioning device for adjusting an axial position of a tool within a wellbore includes an anchor configured for attachment to the wellbore at a fixed axial location within the wellbore, a shaft coupled to the anchor, and a coupling member to which the tool is rigidly attached. The coupling member is configured to be translated along the shaft to adjust the axial position of the tool with respect to the fixed axial location of the anchor within the wellbore.