Ed/Charo,

 If you would like to build a 3.17:1 box and use
 the rear planet one trick is to EDM out the roll pins
 holding the six planet shafts in and replace them with
 hard shoulder bolts. Then screw the shoulder bolts into
 a flange on the prop shaft. Makes a real elegant box.

 This will work on the front planetary too if you wish 2.85:1.

 I am leaning towards a splined prop flange held on with a large nut.
 A lot like a Merlin. Fits a hollow prop shaft well.

 ---------------------------

 Better picture of the Merlin prop shaft.

 Easy to install needle rollers. Also easy to take
 apart and inspect everything.

 Also hundreds of Ross boxes used rollers so a separate oil
 supply is no big deal. No hot high pressure oil from the engine
 required.


 Paul Lamar


Yes, that is my favorite design, with the bolts replacing the planet pins.
I
intended to get back with you on this in the future after getting the
damper
done. There are many automotive wheel spindles that use splined through
bolts to hold them in the hub. I was considering that myself. It just seems
safer than using 6 or 8 bolts.

As I jested at Whitman last time you were there, I don't know how my wife's
name became the title name on my email. Gmail must have done it
automatically when we used one of my wifes email address's as backup.

You should wait till the parts arrive before sending a check, they might be
damaged in route.

Ed Carver

OK Ed.

Yes charo carver is probably the  name used on your account.
When I send a reply that comes up automatically.
Kind of confusing.


Paul Lamar


Paul,  I was  under the impression that the planetary carrier through pins
were the inner race for the planetary gears which would require a precision
finish and exact diameter as well as a fairly high rockwell hardness on the
replacement shoulder bolts

    . Attaching the planetary  carrier and propshaft with a bolted
connection appears desireable as it adds mass and would effect chatter RPM.
Do you  know which way (increased or decreased RPM) the resonance frequency
would change? My interest is due to the fact I am useing the transfer case
planetary which  is several pounds (3?) heavier and will change the
frequency in a similar direction.

       Concerning  damper assemblies, is the silicon or rubber compound
expected to return to it's static shape as fast as the engine pulses
compress it or does it just get held distorted at a pretty much constant
compression. The failure mode on the former clutch disk center springs
suggests that they are moving (and failing)  due to cycling with power
pulses.If the rubber is moving would it not get hot and deteriorate except
for the fact Tracy's open design with the 3"  spacer plates is pretty much
air cooled due to the spinning aluminum damper plate conducting heat away
with it's induced draft?

With the rubber blocks enclosed by two smooth
steel plates and possibly an alternator stater blocking the inflow of
cooling air circulation then heat rejection seems problematic.  I  am still
staring at the drawing for the high pressure laminate damper I designed for
my PSRU (posted last month) trying to anticipate problems it may have. The
worst case seems to be with the high engine idle and a 3 blade prop both
near the 6Hz frequency range.

I got the math formulas from a study of torsional resonance done while
developing  the drive system for the BD-5 after the first design and an
improved design had failed.

george grimes