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

Paul Connor,
I like working from the cockpit, try to visually imagine the gears

(cogs)

turning
a. so with the 13B rotating clockwise (from cockpit)- see above

statement !

In Paul's pusher case the 13B rotates counter clockwise from the

cockpit.

b.and you want your prop rotating clockwise (from cockpit)
c.with the C76 type Planetary gears -and your input shaft rotating
clockwise.
d.your planetary gears rotate opposite (anticlockwise)
e. your annular (ring gear) rotates the same way as your planetary
(anticlockwise)
f.so if you drive from the Annular (ring gear),while holding the

planetary

housing, it's (anticlockwise) ie 2.17:1
g.if you drive from the Planetary housing and hold the annular it's
clockwise 2.85:1
Hope that helps !!
George (down under)

You guys are making this all too complicated - all major engines rotate
anticlockwise when viewed looking at
the output shaft (some exceptions are Corvair, English aircraft engines,

and

DKW). redrives using 2.17
versions of the planetary set,  reverse rotation from the input, and

2.85 do

not -  so choose your prop
on that basis - Vance J.

True Vance.  But add many Honda auto engines to the "backwards" list.

Tracy

 
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