CharlieBiler
Hot Rolled
- Joined
- Mar 11, 2005
- Location
- Connellsville PA
To All,
I am very rusty in the gear calculation department. I need to make gears with the following data.
Lead=1.8264"
Normal D.P.=14.
Pitch Dia.=0.980"
Helix Hand= Left
Helix Angle=59degrees, 19 minutes, 18 seconds
Pressure Angle=14.5 degrees involute
I need to know the diameter of the blank to hob this gear. Does anyone out there remember how to calculate the formulas for helical gears?
I thought that the outer diameter was the number of teeth plus two divided by the diameteral pitch. That would be (7+2)/14. This gives me a bogus answer of 0.6429 inches. The gear has to be near 1.2 inches in diameter. I have a sample of an old gear in my hand and a print from 1982. What am I reading wrong? Working backward I add two to the teeth and take the answer and divide it by my rough measurement of 1.2 inches. That gives me a diametral pitch of 7.5 . Again that is a bogus answer.
Have pity on a poor old fool. I have lost my mind and can nor remember my first year apprentice formulas. I am sunk.
Charlie Biler
I am very rusty in the gear calculation department. I need to make gears with the following data.
Lead=1.8264"
Normal D.P.=14.
Pitch Dia.=0.980"
Helix Hand= Left
Helix Angle=59degrees, 19 minutes, 18 seconds
Pressure Angle=14.5 degrees involute
I need to know the diameter of the blank to hob this gear. Does anyone out there remember how to calculate the formulas for helical gears?
I thought that the outer diameter was the number of teeth plus two divided by the diameteral pitch. That would be (7+2)/14. This gives me a bogus answer of 0.6429 inches. The gear has to be near 1.2 inches in diameter. I have a sample of an old gear in my hand and a print from 1982. What am I reading wrong? Working backward I add two to the teeth and take the answer and divide it by my rough measurement of 1.2 inches. That gives me a diametral pitch of 7.5 . Again that is a bogus answer.
Have pity on a poor old fool. I have lost my mind and can nor remember my first year apprentice formulas. I am sunk.
Charlie Biler