I am building the Taper Attachment HSM Jan/Feb 2004. The Question involves cutting the cross feed arbor gear which is shown as 12 teeth 20 DP. You say that for 12 teeth the correct cutter is #1. This is in error, the correct cutter is #8 for 12 teeth. (1 cuts a rack.) You do not specify the pressure angle, nor depth of cut. I assume it is 14 1/2 deg gear. I calculate:

The max diam is 0.690 = Pitch diam + 2 x addendum. Now 12/20 =.6 = pitch diam. Hence the addendum, then equals 0.45. The addendum is usually 1/Pitch diam

=.05, so this is close. The min clearance =.157/Pitch diam = .007 The milling depth = .097. I would like to know how well your gear meshes with the SB gear, and what parameters you used.

The max diam is 0.690 = Pitch diam + 2 x addendum. Now 12/20 =.6 = pitch diam. Hence the addendum, then equals 0.45. The addendum is usually 1/Pitch diam

=.05, so this is close. The min clearance =.157/Pitch diam = .007 The milling depth = .097. I would like to know how well your gear meshes with the SB gear, and what parameters you used.

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