Ed, the OD on the rear planet ring gear is exactly 5 inches
so cleaning up your tube should work.
However the bearing is 130 MM or 5.118 OD so we will need to
sleeve the ring gear with .118 thick sleeve. The tubing will need
to be bored to 5.118 ID dimension about 5 inches deep.
The set screws going through the sleeve into shallow recesses in
the ring gear. This is for the rear planet set and 3.12:1.
For the 2.85:1 front planet version the sleeve would be somewhat
thicker.

The shafts in the front planet will need to be EDM'ed out to .375.

I have a 2.85:1 front planet carrier in stock. Do you want me to put
that in the EDM shop? It will cost around $150,


Paul Lamar



Guys, is the plan here to make an adapter that will use the stock bell
housing with the tube adapter?
I have my old engine/ mount/ nose gear on my plane at this point because
I wanted to use the retractable gear, and its already mounted to the
engine mount.

I am watching in earnest about the PCM and PSRU, as these are my biggest
worries. My Continental has 2 bad cylinders, and to replace these will
cost as much as a new 20B. So at this point my plan is to assemble an
engine and PSRU for this plane and switch them out.

So, are we planning to use this design to permit use of the stock
bell housing on the rotary?

Kevin Alderman

This is an experimental design. It has not run yet let alone flown.
Ed and I are building two. Yes this version does use the stock auto
tranny bell housing but it is just as easy to build one for the
motor plate. Minor changes. It is just matter of where you weld on
the flange.
The guts from the planet carrier back is the same as Tracy's unit
but the prop shaft is of different design using recently available
thin section ceramic bearings. No convential SAE prop flange is
used. It uses
a new, more or less, standard design that Sensenich and others are
now using that has ground adjustable pitch.

What kind of airplane is that Kevin?


Paul Lamar



Paul,   5.118-5.000 = .118 is the diameter difference so the spacer would
be half that or .059  (.118/2) thick. which sounds really thin to try to
make in a lathe. You might want to overbore to the depth of the
planetary for a thicker wall spacer. Alternatively you might bore from
the prop end for the 5.118 size and something like 5.150 between the
bearing seats and then use a heavy snap ring as the bearing shoulder.
Might be lighter than boring out the back end and replacing part of it
with steel at three times the weight. I assume you will be turning off
unneeded material on the OD of the tube for weight reduction so just
leave the calculated wall thickness off the revised bore diameters.
george grimes

You are right George thanks for catching that.

The weight reduction might not be worth it on the OD of the
tube. If I did that I would taper is so best done in an NC
lathe.

Paul Lamar