Development of an Integrated Slotting Mechanism for Internal Keyway Machining on a Conventional Lathe

Abstract

Conventional lathes, while versatile, lack the capability to machine internal keyways, necessitating dedicated and costly equipment, a significant limitation for small- and medium-sized workshops. This study addresses this gap by developing a novel, mechanically integrated slotting attachment for conventional lathes. The research encompasses the systematic design, force-power analysis, fabrication, and experimental validation of the mechanism. The attachment, mounted on the lathe tool post, utilizes a crank-slider system driven by a stepper motor via an Arduino-based controller to generate a reciprocating cutting motion. Finite element analysis confirms the structural sufficiency of the critical ram shaft under operational loads. Machining experiments on aluminum and carbon steel C35 specimens demonstrate the attachment's practical efficacy, producing internal keyways with high dimensional accuracy (deviations within 0.03 mm for width and 0.05 mm for depth). The results prove that the proposed integration successfully extends lathe functionality, offering a cost-effective, space-saving, and precise solution for internal keyway machining. This work provides a validated design framework for enhancing the versatility of traditional machine tools in resource-constrained manufacturing environments. Moreover, the results prove that the proposed integration successfully extends lathe functionality, offering a cost-effective, repeatable, and precise solution for internal keyway machining.