Got the gears for my new gear box.
This is the back Ford  planet set with steel planet
carrier. Only about 7.5 pounds.

This will allow the p-port engine to rev to about 9,000
for take of making close to 300 HP.

It will be a while before I need it so I'll slowly gather
all the other needed parts together.

It will need a custom input shaft due to the large internal diameter
of the sun gear. I am not comfortable with a sleeve.

There are a couple of ways to get the torque out of
the rotating planet carrier.

1. EDM the roll pins holding the planet shafts in and replace
them with 1/2 inch shoulder bolts. The S-bolt hardness is only C32.

2. EDM a 7/16th hole in each shaft and use a regular 7/16th bolt.

Both methods have their good and bad points.

I'll probably try the first method  first.

What do you think Larry?

Paul Lamar

Paul,
Personally, I would remove the roll pins (by drilling on the opposite side
and punching out) and remove all the stock gears, shafts, bearings and such.
Reverse engineer the steel housing, then I would machine one to fit my
output shaft, reusing all the ford shafts, pins...... the whole lot. It is
the most machine work, but the safe way to go. Ford already figured out how
to make it last, so don't change the core items.
The ring gear can be done with a tight press fit and a couple of roll pins
to lock it. Sun gear can either be done the way Tracy does it, or make a new
shaft and have the sun gear cut on it like the Ross drives. The Tracy method
is fine unless you are going to make lots of power.
Larry

That is a good idea for getting the roll pins out. I did not think of
that. You did :)

On second thought those shoulder bolts have rather lax tolerance
at minus nothing plus .004. C32 is also marginal. Probably better to make
your own. What would a good shoulder bolt cost hardened to Rockwell C50
or so and final ground?

Do you do your own splines or do you farm them out?

Paul Lamar

Paul,
I cut straight splines here, but farm out any involute splines. I would stay
away from using shoulder bolts as the load is applied in single shear and
any deflection in the pin changes gear tooth loading. Whatever carrier you
build, use the pins in double shear.
If I were making pins.... 300M tool steel
Larry

In effect the use of the stock planet carrier straddles the planet shafts.
I will not use the shoulder bolt option. I will have the current
1/2 inch planet shafts EDM-ed out to 3/8th while they are still in the planet
carrier. That way we will keep the stock finish and hardness.

Six 3/8th inch diameter bolts on a 3.25" BC are over kill anyway.
There is room for six 1/4 inch dowel pins as well. The holes are
already in the planet carrier for those. I am not worried :)

BTW the planet carrier is not steel. Probably sintered powdered iron
alloy. We found that out today when we machined the teeth off.

John Lynch turned me on to high fatigue limit 7075 T73 for the prop shaft.
40K fatigue limit. The tensile is a bit down from regular 7075 T6.
He claims it is at least twice as good as 6061 T6.

He also says to chromic acid anodize. The one inch wall is way
over kill so I am thinking of machining it down where possible
to 1/2 inch to save a bit of weight.

Here is a good 7075 source. Sunshine Metals in Orange County
or Future Alloys in the San Fernando valley 818 701 1144

We used John's lathe today. He builds a lot of stuff for F16's.
He also did the 2nd landing gear design and build on the NXT.

Paul Lamar