Gear Cutting

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Forging new generations of engineers
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Gear Cutting
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Making Gears

• Gear cutting equipment
• Preparing a gear blank
• Gear involute cutters
• Cutting a spur gear
• Identify current gear uses
• Apply gear knowledge to real situations

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Diametral Pitch is the actual size of the gear
tooth.The lower the number the larger the
tooth.The chart at left shows 3 dp. as larger
tooth and 20 dp as the smallest tooth.
Diametral Pitch
3 dp
20 dp
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Gear Tooth Parts
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Gear Cutting Equipment

• Metal Lathe
• Horizontal Mill
• Horizontal Cutoff Saw
• Indexing Head
• Drill Bit
• Gear Involute Cutter
• Gear Blank Mandrel

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Gear Cutting Equipment
Horizontal Mill Saw
Cutoff Band Saw
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Gear Cutting Equipment
Metal Lathe
Drill
Gear ToothGage
Gear Blank
Gear Cutter
Mandrel
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Horizontal Cutoff Saw
Cutting Gear Blank
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Metal Lathe Used To Face Sides Of Gear Blank And
Drill A 1 Hole
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Rough Gear Blank Mounted On A Mandrel
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Mandrel And Gear Blank Assembly Mounted On The
Lathe
Turned To Finished Gear Diameter And Thickness
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Indexing Head Used To Exactly Position Gear Blank
To Cut Each Tooth
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Math Gear Calculations

• 16 Diametral Pitch X 2 Inch Diameter Gear Blank
  Equals Number Of Teeth
• N D.P. X D.G. N 16 X 2 N 32 Teeth
• 40 Turns Of The Dividing Head Hand Crank Equals 1
  Revolution Of The Gear Blank
• Turns 40/32 10/8 5/4 1 And 1/4 Turns

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Math Gear Calculations

• Using a 20 hole plate 1/4 turn 20/4 5
  spaces or 6 holes in plate. This moves our gear
  blank 1 and 1/4 turns.
• Outside diameter of gear 32th 2/16 2.125
• Cutting depth for tooth 2.250 a constant
  divided by d.P.
• Depth 2.250/16 .140 thousands for depth of
  cut.

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20 Hole Indexing Plate Mounted On Indexing Head
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Horizontal Mill Set Up With Indexing Head,
Mandrel Gear Blank
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Horizontal Mill Set Up To Cut Gear
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Gear Blank Aligned With Gear Involute Cutter
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Gear Involute Cutter Cutting Gear
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Checking Finished Gear With Involute Gage
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Measuring Finished Gear