12-25-2017, 01:52 AM
Hi,
I've just come across something strange which I don't understand.
I wanted to know the angle of an 8tpi thread on a 3/4" shaft. In metric terms this is close enough to a thread pitch of 3.2mm on a 19mm shaft diameter so the thread angle can be represented by a right angle triangle with non-hypotenuse sides of 3.2mm and 19mm. Rather than calculate the angle, I initially drew the triangle on deltacad and measured the angle using the angular dimension function. I got an answer of 9.6 degrees. I then checked this using the trig formula:
Tan (angle) = 3.2/19
The answer I got was 10.6 degrees. I think this is correct but I don't understand why the angular dimension function gave me a different answer.
Has anyone got any explanation or have I made a silly mistake somewhere along the line?
Regards,
Alan
I've just come across something strange which I don't understand.
I wanted to know the angle of an 8tpi thread on a 3/4" shaft. In metric terms this is close enough to a thread pitch of 3.2mm on a 19mm shaft diameter so the thread angle can be represented by a right angle triangle with non-hypotenuse sides of 3.2mm and 19mm. Rather than calculate the angle, I initially drew the triangle on deltacad and measured the angle using the angular dimension function. I got an answer of 9.6 degrees. I then checked this using the trig formula:
Tan (angle) = 3.2/19
The answer I got was 10.6 degrees. I think this is correct but I don't understand why the angular dimension function gave me a different answer.
Has anyone got any explanation or have I made a silly mistake somewhere along the line?
Regards,
Alan