I PAUL
I FOLLOW YOUR RECOMMENDATION TO DESIGN WITH NEEDLE BEARINGS
AND I CAME UP PRETTY GOOD BUT I NEED YOU TO LOOK AT IT AND
COME BACK WITH YOUR RECOMMENDATIONS.
I AM SENDING YOU 3 2SHEETS WITH DIMENSIONS


Jean Prudhomme


That is looking a lot better Jean.

Make sure the prop flange is the same as one of
these SAE standards. The big one is for wood props
and the smaller one for CS props.

Paul Lamar

P.S. Here is one of Doug's old email messages on the subject.

-----------------------------------------------------------                       
I found out this info from an aviation talk group.  About
bushings source -  still no luck with the thread type with
flange.  I imagine  they are  hot pressed in place.  Hub
thickness is still an unknown.  No lightening holes in mine.  I
heard one person say thickness equals 0.41"  for a IO-540 and
thats is about 10.4 mm.  Mama mia!!  That is overkill for forged
4130. The  Bell 47 prop shaft OD diameter is 3"  so on a SAE #2
the overhang is less than 1.5".  6 - 7 mm thickness should be
adequate. And  yes the shaft  will be VERY hollow.


 SAE AS127D --- it is a grand total of 3 pages.

The following is a summary:

SAE #1 0.375, 4.375, 5.5, 3.38, 0.624, 6, .375-24UNF-3A, 0.500, 0.500, 0.500

SAE #2 0.375, 4.750, 6.0, 3.50, 0.624, 6, .375-24UNF-3A, 0.500, 0.500, 0.500

SAE #3 0.375, 5.250, 6.5, 4.00, 0.624, 8, .375-24UNF-3A, 0.500, 0.500, 0.500

The format of the above numbers is:

Bolt Dia (in), Bolt Circle Dia (in), Flange Dia (in), Prop Thickness (in),
Drive Bush Dia (in), Number of Bolts, Bolt Thread, Drive Bush Height (in),
Bolt Minimum Thread Length (in), Max Distance of End of Bolt From Face of
Hub (in)

Generic Dimensions:

Radius on Corners of the Drive Brushes and Flange 0.03-0.06
Main Flange Centre Boss 2.248-2.250 Dia OD and 2.007-2.009 ID,
1.000" Height above the flange.
Radius between flange and center boss 0.190" Max
Radius on upper corners of center boss 0.03-0.06"

Cheers

Doug in Japan
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