A surgical instrument, comprising: a gearbox assembly, including: a drive gear including a round gear configured to receive a rotational input and a lead screw coupled to the round gear such that the rotational input to the round gear rotates the lead screw; a first hub threadingly engaged about the lead screw such that rotation of the lead screw translates the first hub therealong; a second hub spaced-apart from the first hub; a drive rod engaged with the second hub; and a compression spring disposed between the first and second hubs, wherein, when a force acting against translation of the drive rod is below a threshold, the rotational input translates the first hub to, in turn, translate the compression spring to, in turn, translate the second hub and the drive rod, and wherein, when the force acting against translation of the drive rod is equal to or above the threshold, the rotational input translates the first hub to, in turn, compress the compression spring against the second hub while the second hub and drive rod are maintained in position, characterized in that the gearbox assembly further includes at least one guide bar operably coupled between the first and second hubs (454, 452), the at least one guide bar defining first and second rims (474, 472) configured to interact with first and second shoulders of the first and second hubs, respectively, to define a maximum distance between the first and second hubs, wherein the compression spring is partially compressed when the first and second hubs (454, 452) define the maximum distance therebetween a gearbox assembly, including: a drive gear including a round gear configured to receive a rotational input and a lead screw coupled to the round gear such that the rotational input to the round gear rotates the lead screw; a first hub threadingly engaged about the lead screw such that rotation of the lead screw translates the first hub therealong; a second hub spaced-apart from the first hub; a drive rod engaged with the second hub; and a compression spring disposed between the first and second hubs, wherein, when a force acting against translation of the drive rod is below a threshold, the rotational input translates the first hub to, in turn, translate the compression spring to, in turn, translate the second hub and the drive rod, and wherein, when the force acting against translation of the drive rod is equal to or above the threshold, the rotational input translates the first hub to, in turn, compress the compression spring against the second hub while the second hub and drive rod are maintained in position, a drive gear including a round gear configured to receive a rotational input and a lead screw coupled to the round gear such that the rotational input to the round gear rotates the lead screw; a first hub threadingly engaged about the lead screw such that rotation of the lead screw translates the first hub therealong; a second hub spaced-apart from the first hub; a drive rod engaged with the second hub; and a compression spring disposed between the first and second hubs, wherein, when a force acting against translation of the drive rod is below a threshold, the rotational input translates the first hub to, in turn, translate the compression spring to, in turn, translate the second hub and the drive rod, and wherein, when the force acting against translation of the drive rod is equal to or above the threshold, the rotational input translates the first hub to, in turn, compress the compression spring against the second hub while the second hub and drive rod are maintained in position, characterized in that the gearbox assembly further includes at least one guide bar operably coupled between the first and second hubs (454, 452), the at least one guide bar defining first and second rims (474, 472) configured to interact with first and second shoulders of the first and second hubs, respectively, to define a maximum distance between the first and second hubs, wherein the compression spring is partially compressed when the first and second hubs (454, 452) define the maximum distance therebetween