| Ed,
For the record, I too have experienced two re-drive failures similar to Dave's. Actually, it was one re-drive failure and one flywheel failure.
First I had a pin failure on the sun gear/input shaft. Like Dave, this happened on the ground. The pin was upsized to 3/8" and so far it is working fine. I believe this may have been a result of rough running partially attributed to my less than perfect tuning techniques as well as an EC-2 issue with my CAS. Now that the CAS issue has been resolved, I am cautiously optimistic that this particular failure won't happen again.
The other failure was to the flexplate. While it didn't totally fail, it was just a matter of time as there were cracks forming in the vicinity of the big holes. I've replaced the flexplate with a new one and now check it regularly. One probable cause for the failure was an out-of-true flexplate. The new one is true within .010".
For the record, I'm running a n/a p-ported 20B. I typically see only limited periods of 300+ hp during takeoff/climbout.
Please take good care of YOUR glider trophy, and keep a spot on YOUR mantle for all to admire.
Mark S. On Tue, Jan 10, 2012 at 9:46 AM, Ed Anderson <eanderson@carolina.rr.com> wrote:
Well, Dave, I must say you time your failures much
better than I do.
Your's appear to have the good manners to wait
until you are back on the ground {:>). Actually, its clear your
protocol of checking things after a flight is what has "saved" my glider record
{:<(
Actually, I am impressed that the RD seems to be fairly
robust in failure modes - in that it appears to keep functioning (more or less),
until you are back on the ground.
That kind of HP and the G loading is apparently pushing
the RD to its limits. But, as I am reminded, its only until the limits of
anything are exceeded that you realllllyyyyy know what the limits are - all else
is theoretically {:>). As we both know, it is generally the racer who
finds those limits by pushing the envelop.
So Thanks for that valuable information and the seat
cushions it may have taken to get it.
Ed
Sent: Tuesday, January 10, 2012 9:32 AM
Subject: [FlyRotary] Re: RD1B Failure
Hi Ed,
Yes you have missed quite a saga and several failures. The underlying
cause of that one seems to be that the auto flex plate fatigued and broke,
leading to the pin failure (oversized pin). I replaced the flex plate with
a modified 4130 flywheel that seems much better suited to the purpose than the
flex-plate.
I then had another failure of the RD-1B when the oiling system did not seem
up to the task during my qualifying run at Reno (clocked at 229 mph while
pulling 2Gs around the course). Of course, I was probably making over 300
h.p. and pushing the RD-1B beyond its design limits. Not to mention that
my oil temps were not being measured well and have probably always been higher
than I thought. I am guessing oil temps were in excess of 250F when the
main plain bearing in the RD-1B seized (after landing).
I have since had another failure. This time the sun gear pin seems to
have simply fallen out! Well, it fell out as much as it could until the
housing would not let it completely go, until the
last little piece of the pin sheared off. This was amazingly,
again, discovered on the ground after a long over-mountainous-terrain flight to
Las Vegas.
So despite 4 RD-1B failures in 3 different places all in 2011 (the pin
twice, the flex plate, and the main bearing - probably all related to racing in
Reno that year) I have not made any ground toward threatening your rotary glider
time record. :-)
-- David Leonard Turbo Rotary RV-6 N4VY http://N4VY.RotaryRoster.nethttp://RotaryRoster.net
On Mon, Jul 11, 2011 at 6:57 AM, Ed Anderson <eanderson@carolina.rr.com>
wrote:
Hey, Dave
Glad you didn't further challenge my Glider record
{:>).
I was thinking that perhaps the stress of the Reno
Races might be a contributing factor to the gear box problem.
Particularly if the shear pin was designed for a N/A 13B. Anyhow,
hopefully, it is that simple a cause and you find no further
damage.
Send from Lake of The Ozarks resort - looking out over
the waves and reclining in a lounge chair in the cool morning
breeze
Ed
Sent: Sunday, July 10, 2011 11:58 PM
Subject: [FlyRotary] RD1B Failure
Today had a failure of my RD-1B gear drive. It couldn't
have happened at a better time, I was just taxiing off the runway at my home
airport. I just finished flying 200 mi. to Santa Paula to help Paul with
the getting of Mike Wills airplane back into the air. Flight home was
otherwise unevenful and beautiful. I didn't bother taking it apart, but
will do so tomorrow. Feels like I may have broken the sun gear pin again
but will have to wait until tomorrow to be sure. The strange thing is
that nothing particularly stressed it. Sorry there is not cause I can
report... a little suspense until tomorrow.
--
David
Leonard
Turbo Rotary RV-6 N4VY
http://N4VY.RotaryRoster.net
http://RotaryRoster.net
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