In some embodiments, an insertion device for a robotic surgery apparatus can include one or more guides configured to receive and/or engage a plurality of control links. The one or more guides can each include a plurality of channels. The insertion device can include a tool interface configured to engage one or more surgical tools for performing a surgical procedure. At least one control link of the first, second, or third pluralities of control links can be overlapping, coaxially aligned, or otherwise placed in a nested configuration with respect to another control link of the first, second, or third pluralities of control links. One or more of the plurality of first, second, or third control links can be configured to be actuated to adjust spatial position of the tool interface to facilitate repositioning of the surgical tool.