Vertical and Horizontal Mills

Vertical Mill

Parts u Base and Column u Knee u Saddle u Table u Ram u Tool Head u Quill Feed

Cutter Holding –No more overhang than is necessary u R8 Taper u Solid Collet (most rigid) u Split Collet

Vertical Milling Cutters

End mills u 2 or more flutes u single or double end u straight or helix flute u roughing end mills

Geometry Forming cutters u dovetail - 45 or 60 degree u t-slot u woodruff key u shell end mills u three flute tapered - used for mold making, die work, patterns

Misc cutters u Fly cutters - single point tool often consisting of high speed or carbide tool –take light face cuts from large surface areas u Indexible tooling - many cutter types and shapes –eliminate resharpening u Face mills - flat surfaces

Horizontal Mill

Parts u Base and Column u Knee u Saddle u Table u Spindle u Overarm

Universal Horizontal Mill u similar to plain except it has has an additional housing that supports the table and allows table to swivel 45 deg in either direction in horiz plane –used to machine helical slots or grooves in mill cutters and twist drills, otherwise they are the same as the plain machines

Types of spindles, arbors, and adapters u front end of spindle nose has a tapered socket in a standard milling machine taper. This taper aligns the milling machine adapter or cutter arbor u driving force is provided by two keys located on the spindle nose u these engage slots on the adaptor or arbor

Milling machine spindle nose tapers u #30, #40, #50 (most common), #60

Cutters may be attached u a. directly to the spindle nose u b. on a taper shank arbor (our application)

Taper shank arbor assembly u arbor itself u spacing collars - take up space between cutter and end of arbor u bearing collar - rides in arbor support bearing u arbor support bearing - supports outer end of the arbor

Horizontal Milling Cutters

Arbor driven cutters (most common)

Plain arbor driven cutters - for removing material across entire surface (most common operation) - 3 types u 1. light duty - more teeth u 2. heavy duty - less / heavier teeth u Note: any width 3/4” and less will have straight teeth = more chatter

Side milling cutters - for machining steps or grooves u stagger tooth u inserted tooth (indexable) u 1/2 side

Slitting saws - for slotting and cut-off u stagger tooth u inserted tooth (indexable) u side

Geometry forming u single angle - 45 and 60 most common u double angle - 45, 60 and 90 most common u concave - go by the cutter shape not by the geometry created u convex u corner rounding u gear cutters

Misc. Horizontal Milling setups u 1. straddle milling u 2. gang milling - to machine special shapes and contours on workpiece –cutter rpm calculated for largest dia cutter in gang

Day 2

Work holding methods

1.) Vise (most common) u plain vise u swivel vise u universal vise -swivels 90 deg in vert and 360 in horiz plain

Vise operation u manual u air u hydraulic

Use a lead or rubber hammer to strike handle to tighten

Keep work piece as far into vise as possible without danger of hitting vise

Proper part orientation in vise for cutting pressures u pressure against solid jaw (best) u pressure against movable jaw u pressure parallel to jaws (worst)

Soft jaws

2.) Mounting directly to the table u strap clamps, T-bolts, and step blocks u protect work piece surface with shims when necessary u use parallels or shims under work piece as needed u work piece distorted or damaged with excessive pressures

3.) Pallets

Work edge locating u offset edge finder (accurate) u dial indicator (accurate) u touch off method (less accurate) u paper shim (less accurate)

Hole center locating

Climb (down) vs. Conventional Milling (up)

Selection depends on: u is there backlash compensation u required surface finish u type of material being cut

Climb milling u results in good surface finish - chips not swept back through cut u avoid unless backlash is compensated for

Conventional milling (normally used) u surface finish not as good

Vertical Milling Depth of cut - End mills u Roughing cuts with standard end mills in steel - don’t exceed 1/2 dia. cutter dia. u Finish cuts ”

Horizontal Milling Depth of cut - Arbor driven cutters u roughing cuts =.100 to 200” u finish cuts =.015 to.030” u no less than.015”

Squaring vise and machine head

Vertical Mill u Head squared to table u Vise squared to table

Horizontal Mill u Table squared by mounting indicator on table (Never the column) u Vise squared to table with indicator mounted on overarm