Milling Machines Used to produce one or more machined surfaces accurately on workpiece One or more rotary milling cutters Workpiece held on work table or holding device and brought into contact with cutter Vertical milling machine most common Horizontal milling machine handles operations normally performed by other tools

The Vertical Milling Machine Unit 59

Vertical Milling Machines Equipped with variable speed spindle drives Permit wide range of speeds Spindle head housing swiveled as much as 90 degrees right and left, as well as limited backward and forward for angular operations Longitudinal and crossfeed movements of table operated by hand or automatic feeds

Many facing operations done with fly cutter (cost reduction). Variety of Operations Face milling End milling Keyway cutting Dovetail cutting T-slot and circular slot cutting Gear cutting Drilling Boring Jig boring Many facing operations done with fly cutter (cost reduction).

Types of Vertical Milling Machines Ram-type Most common because of simplicity and setup All features of plain horizontal milling machine Cutter spindle mounted in vertical position Spindle head may be swiveled allowing machining of angular surfaces 2-axis control Step between standard milling machine and CNC machining center (PC control)

Heavy-Duty Vertical Milling Machine Used for machining operations that require larger cutters and good rigidity Adapted to operations with end mills and face mills Profiling interior and exterior surfaces Milling dies and metal molds Locating and boring holes in jigs and fixtures

Ram-Type Vertical Milling Machine

Parts of Ram-Type Vertical Mill Base made of ribbed cast iron May contain coolant reservoir Column often cast with base Machined face provides ways for vertical movement of knee Upper part machines to receive turret where overarm mounted

Parts of Ram-Type Vertical Mill Overarm round and may be adjusted toward or away from column Head attached to end of ram Made to swivel head in one plane Universal-type machines allow swivel in 2 planes Motor mounted on top of head provides drive to spindle through V-belts

Parts of Ram-Type Vertical Mill Spindle speed changed by variable-speed pulley/crank or by belt changes and reduction gear Knee moves up and down on face of column Supports saddle and table Does not contain gears for automatic feed Automatic feed is external device and controls longitudinal and crossfeeds of table