The gear tooth vernier is
made to measure the Chordal thickness of the gear teeth at the pitch
line.Allowance may be made
for any error in blank size by adjusting the height vernier.
Example:
Height Setting
Thickness Setting
= Addendum of gear +
Correction (C)
= Addendum of gear + .0294/4
= Addendum of gear + .007
Height setting for
internal gear (of low pressure angle) = addendum of gear.
Height setting for
internal slotting cutter .=
dedendum of gear
Height setting for
rotary spur cutter .=
dedendum of gear- correction
Height setting for
end milling cutter = dedendum of gear- correction
Height setting for
hob and fly hob ...= dedendum of gear +
correction
Height setting for
gear shaper cutter = dedendum of gear +
correction
Height setting for
rack type generating cutter ..= dedendum of gear
Chart for obtaining
correct addendum B, and chordal thickness T.This chart is based on 1 D.P.; for any other D.P. divide these
values by the desired D.P. (for circular pitch multiply by C.P. over
π)
Height setting for
internal gear (of low pressure angle) = addendum of gear.