1.Except for a 3:1 speed decrease.

2. A proposed straight full-depth spur gear mesh is to consist of a 21-tooth pinion driving a 28-tooth gear. The proposed diametral pitch is to be 3, and the pressure angle is 20. Determine the following, and where possible, show each feature on a simple scale drawing of the gear mesh.

a. Pitch circle for the pinion.

b. Pitch circle for the gear.

c. Pressure angle .

d. Base circle for the pinion.

e. Base circle for the gear.

f. Addendum circle for the pinion .

g. Dedendum circle for the pinion.

h. Addendum circle for the gear.

i. Dedendum circle for the gear.

j. Circular pitch k. Tooth thickness.

k. One typical pinion tooth.

l. One typical gear tooth.

m. Length of action.

n. Base pitch.

o. Profile contact ratio .