Fa according to ANSI B92.1

[[Ja...]]

Hi,

Is this correct way to evaluate spline profile according to ANSI B92.1 ? Tolerance class 5

How does GearPro evaluate ±Fa ??? Where does the numbers come from?

Couldn`t find any information 😞

[[Ch...]]

Kind of confusing compared to gears, basically + or - from pitch point to TIP and + or - from pitch point to TIF.

 

[[Ro...]]

+/-Fa is special, yes.
The picture from the standard (Chris posted it) shows how the calulation has to be done.
It begins with the definition of the "contact" point.
In GEAR PRO you can influence the "contact" point in the subdialog of +/-Fa as follows:

After that the actual profile is aligned on that diameter.
For the calculation of +/-Fa the nominal contour is moved parallel to the max and min deviation of the actual curve.
From the "contact" point into plus direction describes +F, in minus material direction -F.
The sum of both is Fa (as usual for involute gears).

[[Ja...]]

Thank you both 🙂 now it is more clear!