Sign in to follow this  
Followers 0

ROTAX REDRIVES?

20 posts in this topic

Posted (edited)

Which Rotax redrive do you consider best, and why?

Which has a clutch or something to cushion pulses, and does this make it better?

Is the E-drive a lot heavier than the C-drive, and why? Is it stronger?

Any guesstimates of how much they cost new / used?

Thanks for educating me.

EDMO

Edited by Ed In Missouri

Share this post


Link to post
Share on other sites

Posted (edited)

Hi Ed,  Not a lot of difference strength wise between the C and E box.   Basiclly they are the same except the E box has the starter built into the gearbox. If you are using the C box and have electric start, it's mounted on the opposite end of the engine.  Both have the rubber donut that cushions the pulses.    The  A and B box are not as strong as the C or E..   Hope this answers your  questions.   The C gear box is $1499 and the E box is $2140 in my latest LEAF catalog.    Jim Chuk

Edited by Jim Chuk

Share this post


Link to post
Share on other sites

Posted

Hi ED I hope this helps.

A and B boxes have a low torque inertia rating so would limit the prop size,pulse damping is by compressing dished washers.

The C box is much stronger,I have never seen one break yet.Damping is via a rubber donut under rotation torque.

The E box is basically the same but for having an integral starter,a bit heavier and the occasional loss of oil into the starter.

This loss is hard to detect externally and usually fatal for the box.

a clutch is available for the B&C box,ideal for float planes and allegedly allows a steeper approach due to the prop windmilling causing high drag

Fly safe have fun!

Share this post


Link to post
Share on other sites

Posted

The clutch only works with a c box. If you had a clutch on the e box how is the starter going to work :dunno:

The c and e are about the same strength wise, but the e box puts more weight right on the nose of the plane with the starter being right behind the prop.

:BC:

1 person likes this

Share this post


Link to post
Share on other sites

Posted

Thanks for the several good answers - that's enough education for a 4-stroker!

EDMO

Share this post


Link to post
Share on other sites

Posted

Oops got it wrong,the clutch will fit the E but make the starter rudundant

Share this post


Link to post
Share on other sites

Posted

Oops got it wrong,the clutch will fit the E but make the starter rudundant

that's OK Dusty, I now have about 99% more knowledge about Rotax redrives than I had before.

Thanks,

EDMO

Share this post


Link to post
Share on other sites

Posted

Dusty, you correct on that.. I stated it wrong.  Yes you could put the clutch on the E box, but then the starter would not work so you have a more expensive gear box sans starter.  The best route is to just get the C box and put the clutch in it.  Either way you loose the ability to prop the plane should you find yourself with a dead battery unless you drill and tap the clutch bell so you can run a few set screws into the clutch towers in the event that you need to hand prop it.

 

:BC:

1 person likes this

Share this post


Link to post
Share on other sites

Posted

Dusty, you correct on that.. I stated it wrong.  Yes you could put the clutch on the E box, but then the starter would not work so you have a more expensive gear box sans starter.  The best route is to just get the C box and put the clutch in it.  Either way you loose the ability to prop the plane should you find yourself with a dead battery unless you drill and tap the clutch bell so you can run a few set screws into the clutch towers in the event that you need to hand prop it.

 

:BC:

Leni,

What is the purpose of the clutch? If the donut smooths the pulses...

EDMO

Share this post


Link to post
Share on other sites

Posted

Allows the engine to idle at half the rpm and start much easier with no load on it. Also allows for steeper approaches with the prop freewheeling.

Share this post


Link to post
Share on other sites

Posted

Allows the engine to idle at half the rpm and start much easier with no load on it. Also allows for steeper approaches with the prop freewheeling.

How is it engaged / disconnected? Is it centripetal?

Thanks,

EDMO

Share this post


Link to post
Share on other sites

Posted

It is a centrifugal clutch.  Engaged by increasing engine crankshaft rpm.

Share this post


Link to post
Share on other sites

Posted (edited)

It is a centrifugal clutch.  Engaged by increasing engine crankshaft rpm.

And centripetal when disengaging - My physics instructor should be laughing about now! (one of his favorites to confuse us)

Thanks Larry,

EDMO

Edited by Ed In Missouri

Share this post


Link to post
Share on other sites

Posted

Actually most use a spring to disengage at or below the breakout rpm.  Varying this spring strength allows for tuning the engagement rpm to tailor the clutch to the engine's torque curve.

 

Centripetal force is opposite to centrifugal force, which would be the force exerted by the spring (within R66) in this case.

 

rk400clutchparts.jpg

1 person likes this

Share this post


Link to post
Share on other sites

Posted

Now I get a better understanding of what this is -

Thanks for the picture Larry.

EDMO

Share this post


Link to post
Share on other sites

Posted

:siterocks:  Today I learned the difference between centripetal and centrifugal force!  

Share this post


Link to post
Share on other sites

Posted

Another successful day.   :siterocks:

Share this post


Link to post
Share on other sites

Posted

Took me 3 years of school to learn the difference between an outside loop and an inside loop!

...or a slip and a skid!

...or a forward and side slip!

Share this post


Link to post
Share on other sites

Posted

Or how-about a Chaundel or Immelmann ?

Share this post


Link to post
Share on other sites

Posted

Wow ... Good stuff guys !

Share this post


Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!


Register a new account

Sign in

Already have an account? Sign in here.


Sign In Now
Sign in to follow this  
Followers 0