Paul The retaining plate for the ring gear used on 2.85 redrive shows
 8 flat head machine screws to hold it in place do you have any idea what
 size ? I have my housing machined so all will fit and I am ready to
 drill and tap housing to hold retaining plate Thanks Keith

 No I don't but my guess is 1/4 28 would do.
 What is the bolt circle diameter?
 I have the dwg but I'll have to load it into Rhino
 and scale it. Looks like there is room for 5/16th.

 Paul Lamar

 -Paul the largest diameter bolt circle useing 3/16 flat head will
 just clear the ring gear and at that diameter I can put nuts on
 outside of the housing if I go to larger flat head then bolt circle
 diameter will be required
 thanks Keith-

 In theory a 3/16 bolt should hold a shear load of 4000 pounds
 assuming a 150,000 psi bolt.
 Times eight is 32,000 pounds. If the bolt circle diameter is
 about 3.5 inches that is a torque of 112,000 inch pounds
 or 9000 foot pounds. That should do it.

 Paul Lamar

 Thank you Paul you sure are a good help
 Keith--


It seems counter intuitive.
Let me go through the math again as I have a bit more time
right now.

3/16th is .1875 diameter. The area of a circle is pi X R squared.
R is .09375.  R squared is .00879  times 3.1416 is .0276 square
inches times 150,000 psi is 4142 pounds shear which blows me away :)
Per screw!!!!! Eight times that is 33,137 pounds. On a 3.5 inch
bolt circle that is 115,976 inch pounds. Divide by 12 and
that is 9664 foot pounds. Wow!! The factor of safety appears to
be 10.

The early Power Sort used a whole bunch of screws to fasten
the prop shaft to the ring gear.

Apparently bolt on prop flanges are a good way to go if
you have a 2 inch or larger prop shaft.

Check my arithmetic and logic.


Paul Lamar