Hi, fellow rotary enthusiasts.  I have a Ross 2.85 redrive on a

pusher

airplane. (SQ2000)  If I

understand it correctly, the ross 2.85 reverses the direction of

rotation, and the 2.17 does not?

If that is the case, it would seem that a 2.17 redrive would allow

me to

use a standard pusher

propeller, as on a LongEZ, Cozy, Veliocity, etc, whereas with the

2.85 I

must use a non-standard

propeller?
    I guess the other side of the coin is that I may realize more

power

at the higher RPMs that

the 2.85 will allow?   Thanks in advance for your replies.  Paul

Conner,

Mobile, AL

The 2.17:1 rotates backwards for a tractor Lycon so should also be

backwards

for a pusher Lycon. the 2.85 rotates correctly for a tractor Lycon so

should also

be correct for a pusher LyCon prop.

I would stick to the 2.85 any event for the additional take off power.

Paul Lamar

Hi, Paul....I looked at a Lycoming powered Cessna. When viewed from

the

cockpit, the prop turns clockwise, and on my friend's cozy, when viewed

from

behind the aircraft, the prop rotates counterclockwise, of course.
       You mentioned in your recent post that the rotary turns
counterclockwise when facing the flywheel. Since my 2.85 to 1 Ross will
reverse that direction, the prop will then rotate clockwise. Opposite

from a

Lycoming powered pusher.  Am I missing something?  Thanks again for your
reply.  Paul Conner

It is easy to check. Rotate the Ross input shaft clockwise looking
at it from the big end and watch what happens.

Paul Lamar
 Response:  I had already done that test, Paul.....When I rotate the Sun

gear, the larger ring gear turns the opposite direction. 

Well then you have a 2.17:1 Ross. Power is removed from the ring
gear. Stock props won't work and you won't enjoy the HP benefits 
of the extra 1500 RPM. PL

What confused me
was that when I sent in a picture of my redrive disassembled, Ian replied:
"Paul, the photograph is the 2.85 redrive with top hat thrust bearing
holder....I have one for free".  I assumed he was talking about the picture
I had sent in. In retrospect, he was probably talking about the picture you
sent which showed where the thrust bearing should go.  What also confused me
is that the 4 planetary gears are held in position, and the ring gear
rotates. I thought that was typical of the 2.85, and that the 2.17 drive had
the 4 planetary gears driven.  I am obviously mixing the characteristics of
the two drives together....However, one thing is for certain.....the center
shaft that is inserted into the flywheel rotates the opposite direction of
the prop hub, and the 4 planetary gear holder is fixed.  Hope this helps,
and I am sorry for the confusion.  sincerely, Paul Conner

 
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