Tracy Crook wrote:

The one shown is the forward planet set.  The 2.176 - 1 redrive uses the
REAR planet set.  Do you know if they make the rear set in a six pinion
version?  I haven't been able to find one.

Tracy Crook
rws@altavista.net
www.rotaryaviation.com

I just took another look at the three pinion forward planet set and their appears to
be 
two different sizes. The TX guts I have has three planet sets. (I think it is an 
over drive version of the C6) A much larger three pinion one and a three pinion one
about 
the same size with a bigger sun gear. 

The ring gear pitch diameter of the four pinion PS now in use is about 4.5 inches.
The pinion gears are about 1.25 and the sun gear about 2.00.
Tracy please check your sizes and see if we are talking about the
same parts. We will call this planet set A.

The ring gear pitch diameter of the big, three pinion PS is about 4.75 inches.
The pinion diameter is about 1.5 inches and the sun gear is also about 2.00 inches
but with a slightly different tooth form. We will call this planet set B.

The ring gear pitch diameter of the small, three pinion PS is about 4.50 inches.
The pinion diameter is about 1 inches and the sun gear is a huge 2.25 inches.
We will call this planet set C.

I am not sure which one Performance Automatic converts to a six pinion version
as they did not have one in stock to measure. Actually Harvey at performance 
automatic did not seem too knowledgeable about the product so
they probably sell something that someone else makes. You might have to buy
one to find out.

The big three pinion PS (B) is larger all around than the rear four pinion planet set
(A). 
So the matching front sun gear and ring gear must be used
as well if the alternative scenario mentioned above is going to work (I think). 
The gear ratio of PS (B) is yet to be determined.

Thanks to Virgil for sending me a complete set of guts for an OD version ( I think)
of
the Ford automatic transmission.

http:www.performanceautomatic.com

I need to visit the automatic transmission parts store and nail down these part
numbers after Sun & Fun. I will also take pictures of these larger parts and
upload them here. This might be the ultimate answer to a PSRU for the three rotor
20B.

Paul Lamar
 
The Aircraft Rotary Engine Newsletter.              Powered by Linux.

http://home.earthlink.net/~rotaryeng/            http://www.linux.org