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Vertical and Horizontal Mills. Vertical Mill. Parts. Base and Column Knee Saddle Table Ram Tool Head Quill Feed. Cutter Holding. No more overhang than is necessary R8 Taper Solid Collet (most rigid) Split Collet. Vertical Milling Cutters. End mills. 2 or more flutes
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Parts • Base and Column • Knee • Saddle • Table • Ram • Tool Head • Quill Feed
Cutter Holding • No more overhang than is necessary • R8 Taper • Solid Collet (most rigid) • Split Collet
End mills • 2 or more flutes • single or double end • straight or helix flute • roughing end mills
Geometry Forming cutters • dovetail - 45 or 60 degree • t-slot • woodruff key • shell end mills • three flute tapered - used for mold making, die work, patterns
Misc cutters • Fly cutters - single point tool often consisting of high speed or carbide tool • take light face cuts from large surface areas • Indexible tooling - many cutter types and shapes • eliminate resharpening • Face mills - flat surfaces
Parts • Base and Column • Knee • Saddle • Table • Spindle • Overarm
Universal Horizontal Mill • 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 • 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 • driving force is provided by two keys located on the spindle nose • these engage slots on the adaptor or arbor
Milling machine spindle nose tapers • #30, #40, #50 (most common), #60
Cutters may be attached • a. directly to the spindle nose • b. on a taper shank arbor (our application)
Taper shank arbor assembly • arbor itself • spacing collars - take up space between cutter and end of arbor • bearing collar - rides in arbor support bearing • arbor support bearing - supports outer end of the arbor
Plain arbor driven cutters - for removing material across entire surface (most common operation) - 3 types • 1. light duty - more teeth • 2. heavy duty - less / heavier teeth • Note: any width 3/4” and less will have straight teeth = more chatter
Side milling cutters - for machining steps or grooves • stagger tooth • inserted tooth (indexable) • 1/2 side
Slitting saws - for slotting and cut-off • stagger tooth • inserted tooth (indexable) • side
Geometry forming • single angle - 45 and 60 most common • double angle - 45, 60 and 90 most common • concave - go by the cutter shape not by the geometry created • convex • corner rounding • gear cutters
Misc. Horizontal Milling setups • 1. straddle milling • 2. gang milling - to machine special shapes and contours on workpiece • cutter rpm calculated for largest dia cutter in gang
1.) Vise (most common) • plain vise • swivel vise • universal vise -swivels 90 deg in vert and 360 in horiz plain
Vise operation • manual • air • hydraulic
Keep work piece as far into vise as possible without danger of hitting vise
Proper part orientation in vise for cutting pressures • pressure against solid jaw (best) • pressure against movable jaw • pressure parallel to jaws (worst)
2.) Mounting directly to the table • strap clamps, T-bolts, and step blocks • protect work piece surface with shims when necessary • use parallels or shims under work piece as needed • work piece distorted or damaged with excessive pressures
Work edge locating • offset edge finder (accurate) • dial indicator (accurate) • touch off method (less accurate) • paper shim (less accurate)
Selection depends on: • is there backlash compensation • required surface finish • type of material being cut
Climb milling • results in good surface finish - chips not swept back through cut • avoid unless backlash is compensated for
Conventional milling (normally used) • surface finish not as good
Vertical Milling Depth of cut - End mills • Roughing cuts with standard end mills in steel - don’t exceed 1/2 dia. cutter dia. • Finish cuts - .005 - .010”
Horizontal Milling Depth of cut - Arbor driven cutters • roughing cuts = .100 to 200” • finish cuts = .015 to .030” • no less than .015”
Vertical Mill • Head squared to table • Vise squared to table
Horizontal Mill • Table squared by mounting indicator on table (Never the column) • Vise squared to table with indicator mounted on overarm