The helical gear thrust formula is  T = F * TAN(helix angle)
F is the tangential force and T is the thrust in pounds.
The Ford C6 sun gear has pitch diameter of roughly 1.8 inches.
>From that you can figure the tangential force given the torque.
The helix angle from eyeball is about either 30 degrees or 60
degrees depending. Probably around 30 degrees.

I think Tracy knows what angle it is exactly.

Paul Lamar

I'm not a math wizz but I thought the formula used the cosine of the helix
angle.  I agree that the 1100+ pounds you got does not sanity check.  Think
I got around 800 pounds when I calculated it.   Somebody out there help us
math challenged types!

Tracy Crook
tcrook@rotaryaviation.com
www.rotaryaviation.com

Speak for yourself :-)
The formula is correct. Don't know where I found the first one
but I confirmed it from Stock Drive Products 1990 Handbook of Gears
page T57.

I think the angle is more like 16 degrees and not 22 
(the rise is .5 inches in 1.68 inches) as Finn stated so if that
is the case the thrust load is a more reasonable 764 pounds
which jibes better with your calculations Tracy.

I am still not sure of that angle as I don't know how to measure
it accurately yet. I think you need to unscrew it and measure
the angle of rotation as one tooth is completely uncovered.
It could very well be 22 degrees as Finn claims.

Paul Lamar
 
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