CNC Lathe Project - Ben B's Portfolio

At robotics, one machine that gets used fairly often is our small lathe. Its main job is to make grooves in shafts for snap on retaining rings. Making these grooves manually takes time and labor. So, one of our mentors brought in a tiny, low cost lathe which had most of its parts taken from it. I am currently helping to convert this lathe into a computer controlled lathe which can automatically create snap ring grooves with greater accuracy, faster and with less work.

Thick aluminum parts I cut on the bandsaw then milled to shape.

The 3 Phase motor and Variable Frequency Drive.

A wiring diagram for the industrial Westinghouse Variable Frequency Drive.

Lathe assembly on cart with control computer and touch screeen.

One of the stepper motors used for controlling the lathe axis.

Parts

Small Low Cost Manual Lathe
Large 1/2 Horsepower 3 Phase Motor
Three Phase Variable Frequency Drive
High Torque Stepper Motors
Stepper Motor Drivers
Rotary Encoder for Sensing Speed

We started by stripping the lathe down to its bare mechanical components. I, then, designed and machined motor mounting brackets to support a much larger and more powerful motor upgrade. This new motor was a 240 Volt, 3 Phase induction motor, which meant it didn’t run off normal wall outlet power. We needed a VFD, or Variable Frequency Drive, to convert the single phase power from a wall outlet to 3 phase power to run the motor. A huge benefit of using a VFD is that you can program it to have many inputs and outputs, to control the motor from software or sensors. VFD also provides speed and torque control, and can regulate current draw and temperature.