Lauren Chai

Goal: design and build desktop lathe capable of cutting 1-inch diameter aluminum stock with precision of 50 microns. Furthermore, lathe needed to be designed to survive a drop from waist height, impact from sledgehammer, bodyweight static load. The lathe was designed and constructed as the team project (6 members) for the class 'Design of Machine Elements' at MIT. 

Final machine survived a 3 foot drop test, sledgehammer test and human weight test (static load of ~120 lbs) with no loss in function and successfully demonstrated ability to cut aluminum to required precision.

My role as ‘parametric analysis guru’ meant I was responsible for generating the main model calculations including, but not limited to:

• estimating static and dynamic loads from external forces and heat expansion

• building a multi-level tolerance stack estimating resultant deflections and the lathe’s error budget.

• Bearing load calculations for life and strength. Select parts using calculations.

Additionally, I assisted with part production and measurements post-machining (e.g., spindle runout and circularity), checking drawings and process plans, including meetings with machine shop instructors to review process plans and ensure drawings incorporated GD&T standards before production.

I later adapted the desktop lathe to have micro-controller control of the spindle motor and the bed’s 2 axes. See Lathe Electromechanical Control for more details.