An automated device facilitates the assembly a surgical instrument that includes a knife with a high aspect ratio. The automated device includes a fixture for restraining a subassembly of the surgical instrument that includes the knife. A blade grip on the device is movable relative to the fixture, and is configured to urge the knife into a restrained position in the subassembly suitable for the subsequent assembly of an additional instrument component. A grip actuator is provided to move the blade grip.