I tried out my modifications to the Elite elevator spades this morning. The following information pertains to an elevator with spades aleady cut down to 4 1/4" wide. Also, the airplane is on amphib. floats.
Before modification of the spade leading edge, the cross section was per Murphy's design - i.e. rectangular with rounded corners. In this configuration, when pulsed downwards in cruise flight, the aircraft continues to pitch downwards - i.e. the airplane demonstrates negative dynamic stability in pitch, stick free. This pilot ran out of courage before the airplane ran out of forward pitching tendancy. Everything happens quite slowly, so is readily controllable hands on. In fact, pilots don't tend to notice the behaviour until it's pointed out to them.
The modification consists of changing the spade leading edge cross section to a semi circle. The resulting handling is certainly an improvement. The pitch stability is now just positively stable. When you pulse the stick forward and release it, the nose stays where it is for a second or so - it may even pitch a degree or so further down - then very slowly returns to the trimmed attitude. This takes about 17 seconds. I'd rather see it take something like 3 - 5 seconds. However, I'd say the change is well worth making. If anybody has any other ideas to further improve the situation, I'd like to hear them.
Al
Elite #587
-----------------------------------------------------------------
List archives located at: https://mail.dcsol.com/login
username "rebel" password "builder"
Unsubscribe: rebel-builders-unsubscribe@dcsol.com
List administrator: mike.davis@dcsol.com
-----------------------------------------------------------------
Do you want this big green box to go away? Well here's how...
Click here for full update
Wildcat! photo archives restored.
Click here for full update
Donors can now disable ads.
Click here for instructions
Add yourself to the user map.
Click here for instructions
Click here for full update
Wildcat! photo archives restored.
Click here for full update
Donors can now disable ads.
Click here for instructions
Add yourself to the user map.
Click here for instructions
Modified Elite Elevator
-
Wayne G. O'Shea
Modified Elite Elevator
THANKS for the mod report Al !
Wayne
----- Original Message -----
From: "Alan Hepburn" <ahepburn@renc.igs.net>
To: <rebel-builders@dcsol.com>
Sent: Tuesday, November 08, 2005 5:51 PM
Subject: Modified Elite Elevator
down to 4 1/4" wide. Also, the airplane is on amphib. floats.
configuration, when pulsed downwards in cruise flight, the aircraft
continues to pitch downwards - i.e. the airplane demonstrates negative
dynamic stability in pitch, stick free. This pilot ran out of courage
before the airplane ran out of forward pitching tendancy. Everything
happens quite slowly, so is readily controllable hands on. In fact, pilots
don't tend to notice the behaviour until it's pointed out to them.
pitch stability is now just positively stable. When you pulse the stick
forward and release it, the nose stays where it is for a second or so - it
may even pitch a degree or so further down - then very slowly returns to the
trimmed attitude. This takes about 17 seconds. I'd rather see it take
something like 3 - 5 seconds. However, I'd say the change is well worth
making. If anybody has any other ideas to further improve the situation,
I'd like to hear them.
-----------------------------------------------------------------
List archives located at: https://mail.dcsol.com/login
username "rebel" password "builder"
Unsubscribe: rebel-builders-unsubscribe@dcsol.com
List administrator: mike.davis@dcsol.com
-----------------------------------------------------------------
Wayne
----- Original Message -----
From: "Alan Hepburn" <ahepburn@renc.igs.net>
To: <rebel-builders@dcsol.com>
Sent: Tuesday, November 08, 2005 5:51 PM
Subject: Modified Elite Elevator
The following information pertains to an elevator with spades aleady cutI tried out my modifications to the Elite elevator spades this morning.
down to 4 1/4" wide. Also, the airplane is on amphib. floats.
Murphy's design - i.e. rectangular with rounded corners. In thisBefore modification of the spade leading edge, the cross section was per
configuration, when pulsed downwards in cruise flight, the aircraft
continues to pitch downwards - i.e. the airplane demonstrates negative
dynamic stability in pitch, stick free. This pilot ran out of courage
before the airplane ran out of forward pitching tendancy. Everything
happens quite slowly, so is readily controllable hands on. In fact, pilots
don't tend to notice the behaviour until it's pointed out to them.
to a semi circle. The resulting handling is certainly an improvement. TheThe modification consists of changing the spade leading edge cross section
pitch stability is now just positively stable. When you pulse the stick
forward and release it, the nose stays where it is for a second or so - it
may even pitch a degree or so further down - then very slowly returns to the
trimmed attitude. This takes about 17 seconds. I'd rather see it take
something like 3 - 5 seconds. However, I'd say the change is well worth
making. If anybody has any other ideas to further improve the situation,
I'd like to hear them.
Al
Elite #587
-----------------------------------------------------------------
List archives located at: https://www.dcsol.com/login
username "rebel" password "builder"
Subscription services located at:
https://www.dcsol.com/public/code/html-subscribe.htm
List administrator: mike.davis@dcsol.com
-----------------------------------------------------------------
-----------------------------------------------------------------
List archives located at: https://mail.dcsol.com/login
username "rebel" password "builder"
Unsubscribe: rebel-builders-unsubscribe@dcsol.com
List administrator: mike.davis@dcsol.com
-----------------------------------------------------------------
-
Keith B. Oliver
Modified Elite Elevator
Question
when you cut down the spades to 4 1/4" did you also reduce the size/weight
of the lead ??
Keith
Elite #654
-----Original Message-----
From: mike.davis@dcsol.com [mailto:mike.davis@dcsol.com]On Behalf Of
Alan Hepburn
Sent: Tuesday, November 08, 2005 5:51 PM
To: rebel-builders@dcsol.com
Subject: Modified Elite Elevator
I tried out my modifications to the Elite elevator spades this morning. The
following information pertains to an elevator with spades aleady cut down to
4 1/4" wide. Also, the airplane is on amphib. floats.
Before modification of the spade leading edge, the cross section was per
Murphy's design - i.e. rectangular with rounded corners. In this
configuration, when pulsed downwards in cruise flight, the aircraft
continues to pitch downwards - i.e. the airplane demonstrates negative
dynamic stability in pitch, stick free. This pilot ran out of courage
before the airplane ran out of forward pitching tendancy. Everything
happens quite slowly, so is readily controllable hands on. In fact, pilots
don't tend to notice the behaviour until it's pointed out to them.
The modification consists of changing the spade leading edge cross section
to a semi circle. The resulting handling is certainly an improvement. The
pitch stability is now just positively stable. When you pulse the stick
forward and release it, the nose stays where it is for a second or so - it
may even pitch a degree or so further down - then very slowly returns to the
trimmed attitude. This takes about 17 seconds. I'd rather see it take
something like 3 - 5 seconds. However, I'd say the change is well worth
making. If anybody has any other ideas to further improve the situation,
I'd like to hear them.
Al
Elite #587
-----------------------------------------------------------------
List archives located at: https://www.dcsol.com/login
username "rebel" password "builder"
Subscription services located at:
https://www.dcsol.com/public/code/html-subscribe.htm
List administrator: mike.davis@dcsol.com
-----------------------------------------------------------------
-----------------------------------------------------------------
List archives located at: https://mail.dcsol.com/login
username "rebel" password "builder"
Unsubscribe: rebel-builders-unsubscribe@dcsol.com
List administrator: mike.davis@dcsol.com
-----------------------------------------------------------------
when you cut down the spades to 4 1/4" did you also reduce the size/weight
of the lead ??
Keith
Elite #654
-----Original Message-----
From: mike.davis@dcsol.com [mailto:mike.davis@dcsol.com]On Behalf Of
Alan Hepburn
Sent: Tuesday, November 08, 2005 5:51 PM
To: rebel-builders@dcsol.com
Subject: Modified Elite Elevator
I tried out my modifications to the Elite elevator spades this morning. The
following information pertains to an elevator with spades aleady cut down to
4 1/4" wide. Also, the airplane is on amphib. floats.
Before modification of the spade leading edge, the cross section was per
Murphy's design - i.e. rectangular with rounded corners. In this
configuration, when pulsed downwards in cruise flight, the aircraft
continues to pitch downwards - i.e. the airplane demonstrates negative
dynamic stability in pitch, stick free. This pilot ran out of courage
before the airplane ran out of forward pitching tendancy. Everything
happens quite slowly, so is readily controllable hands on. In fact, pilots
don't tend to notice the behaviour until it's pointed out to them.
The modification consists of changing the spade leading edge cross section
to a semi circle. The resulting handling is certainly an improvement. The
pitch stability is now just positively stable. When you pulse the stick
forward and release it, the nose stays where it is for a second or so - it
may even pitch a degree or so further down - then very slowly returns to the
trimmed attitude. This takes about 17 seconds. I'd rather see it take
something like 3 - 5 seconds. However, I'd say the change is well worth
making. If anybody has any other ideas to further improve the situation,
I'd like to hear them.
Al
Elite #587
-----------------------------------------------------------------
List archives located at: https://www.dcsol.com/login
username "rebel" password "builder"
Subscription services located at:
https://www.dcsol.com/public/code/html-subscribe.htm
List administrator: mike.davis@dcsol.com
-----------------------------------------------------------------
-----------------------------------------------------------------
List archives located at: https://mail.dcsol.com/login
username "rebel" password "builder"
Unsubscribe: rebel-builders-unsubscribe@dcsol.com
List administrator: mike.davis@dcsol.com
-----------------------------------------------------------------
-
Scott Aldrich
Modified Elite Elevator
Al, pictures of the tips?
Thanks,
Scott
-----Original Message-----
From: mike.davis@dcsol.com [mailto:mike.davis@dcsol.com] On Behalf Of Alan
Hepburn
Sent: Tuesday, November 08, 2005 3:51 PM
To: rebel-builders@dcsol.com
Subject: Modified Elite Elevator
I tried out my modifications to the Elite elevator spades this morning. The
following information pertains to an elevator with spades aleady cut down to
4 1/4" wide. Also, the airplane is on amphib. floats.
Before modification of the spade leading edge, the cross section was per
Murphy's design - i.e. rectangular with rounded corners. In this
configuration, when pulsed downwards in cruise flight, the aircraft
continues to pitch downwards - i.e. the airplane demonstrates negative
dynamic stability in pitch, stick free. This pilot ran out of courage
before the airplane ran out of forward pitching tendancy. Everything
happens quite slowly, so is readily controllable hands on. In fact, pilots
don't tend to notice the behaviour until it's pointed out to them.
The modification consists of changing the spade leading edge cross section
to a semi circle. The resulting handling is certainly an improvement. The
pitch stability is now just positively stable. When you pulse the stick
forward and release it, the nose stays where it is for a second or so - it
may even pitch a degree or so further down - then very slowly returns to the
trimmed attitude. This takes about 17 seconds. I'd rather see it take
something like 3 - 5 seconds. However, I'd say the change is well worth
making. If anybody has any other ideas to further improve the situation,
I'd like to hear them.
Al
Elite #587
-----------------------------------------------------------------
List archives located at: https://www.dcsol.com/login
username "rebel" password "builder"
Subscription services located at:
https://www.dcsol.com/public/code/html-subscribe.htm
List administrator: mike.davis@dcsol.com
-----------------------------------------------------------------
-----------------------------------------------------------------
List archives located at: https://mail.dcsol.com/login
username "rebel" password "builder"
Unsubscribe: rebel-builders-unsubscribe@dcsol.com
List administrator: mike.davis@dcsol.com
-----------------------------------------------------------------
Thanks,
Scott
-----Original Message-----
From: mike.davis@dcsol.com [mailto:mike.davis@dcsol.com] On Behalf Of Alan
Hepburn
Sent: Tuesday, November 08, 2005 3:51 PM
To: rebel-builders@dcsol.com
Subject: Modified Elite Elevator
I tried out my modifications to the Elite elevator spades this morning. The
following information pertains to an elevator with spades aleady cut down to
4 1/4" wide. Also, the airplane is on amphib. floats.
Before modification of the spade leading edge, the cross section was per
Murphy's design - i.e. rectangular with rounded corners. In this
configuration, when pulsed downwards in cruise flight, the aircraft
continues to pitch downwards - i.e. the airplane demonstrates negative
dynamic stability in pitch, stick free. This pilot ran out of courage
before the airplane ran out of forward pitching tendancy. Everything
happens quite slowly, so is readily controllable hands on. In fact, pilots
don't tend to notice the behaviour until it's pointed out to them.
The modification consists of changing the spade leading edge cross section
to a semi circle. The resulting handling is certainly an improvement. The
pitch stability is now just positively stable. When you pulse the stick
forward and release it, the nose stays where it is for a second or so - it
may even pitch a degree or so further down - then very slowly returns to the
trimmed attitude. This takes about 17 seconds. I'd rather see it take
something like 3 - 5 seconds. However, I'd say the change is well worth
making. If anybody has any other ideas to further improve the situation,
I'd like to hear them.
Al
Elite #587
-----------------------------------------------------------------
List archives located at: https://www.dcsol.com/login
username "rebel" password "builder"
Subscription services located at:
https://www.dcsol.com/public/code/html-subscribe.htm
List administrator: mike.davis@dcsol.com
-----------------------------------------------------------------
-----------------------------------------------------------------
List archives located at: https://mail.dcsol.com/login
username "rebel" password "builder"
Unsubscribe: rebel-builders-unsubscribe@dcsol.com
List administrator: mike.davis@dcsol.com
-----------------------------------------------------------------
-
Wayne G. O'Shea
Modified Elite Elevator
Theoretically, to keep the same % of balance, you would increase the weight
as it's there to static balance the elevator and removing half the spade
takes weight away from that side of the teeter totter.
----- Original Message -----
From: "Keith B. Oliver" <kb_oliver@verizon.net>
To: <rebel-builders@dcsol.com>
Sent: Tuesday, November 08, 2005 6:17 PM
Subject: RE: Modified Elite Elevator
-----------------------------------------------------------------
List archives located at: https://mail.dcsol.com/login
username "rebel" password "builder"
Unsubscribe: rebel-builders-unsubscribe@dcsol.com
List administrator: mike.davis@dcsol.com
-----------------------------------------------------------------
as it's there to static balance the elevator and removing half the spade
takes weight away from that side of the teeter totter.
----- Original Message -----
From: "Keith B. Oliver" <kb_oliver@verizon.net>
To: <rebel-builders@dcsol.com>
Sent: Tuesday, November 08, 2005 6:17 PM
Subject: RE: Modified Elite Elevator
TheQuestion
when you cut down the spades to 4 1/4" did you also reduce the size/weight
of the lead ??
Keith
Elite #654
-----Original Message-----
From: mike.davis@dcsol.com [mailto:mike.davis@dcsol.com]On Behalf Of
Alan Hepburn
Sent: Tuesday, November 08, 2005 5:51 PM
To: rebel-builders@dcsol.com
Subject: Modified Elite Elevator
I tried out my modifications to the Elite elevator spades this morning.
tofollowing information pertains to an elevator with spades aleady cut down
pilots4 1/4" wide. Also, the airplane is on amphib. floats.
Before modification of the spade leading edge, the cross section was per
Murphy's design - i.e. rectangular with rounded corners. In this
configuration, when pulsed downwards in cruise flight, the aircraft
continues to pitch downwards - i.e. the airplane demonstrates negative
dynamic stability in pitch, stick free. This pilot ran out of courage
before the airplane ran out of forward pitching tendancy. Everything
happens quite slowly, so is readily controllable hands on. In fact,
Thedon't tend to notice the behaviour until it's pointed out to them.
The modification consists of changing the spade leading edge cross section
to a semi circle. The resulting handling is certainly an improvement.
thepitch stability is now just positively stable. When you pulse the stick
forward and release it, the nose stays where it is for a second or so - it
may even pitch a degree or so further down - then very slowly returns to
trimmed attitude. This takes about 17 seconds. I'd rather see it take
something like 3 - 5 seconds. However, I'd say the change is well worth
making. If anybody has any other ideas to further improve the situation,
I'd like to hear them.
Al
Elite #587
-----------------------------------------------------------------
List archives located at: https://www.dcsol.com/login
username "rebel" password "builder"
Subscription services located at:
https://www.dcsol.com/public/code/html-subscribe.htm
List administrator: mike.davis@dcsol.com
-----------------------------------------------------------------
-----------------------------------------------------------------
List archives located at: https://www.dcsol.com/login
username "rebel" password "builder"
Subscription services located at:
https://www.dcsol.com/public/code/html-subscribe.htm
List administrator: mike.davis@dcsol.com
-----------------------------------------------------------------
-----------------------------------------------------------------
List archives located at: https://mail.dcsol.com/login
username "rebel" password "builder"
Unsubscribe: rebel-builders-unsubscribe@dcsol.com
List administrator: mike.davis@dcsol.com
-----------------------------------------------------------------
-
Alan Hepburn
Modified Elite Elevator
I'll download some pics once I get the chance to take them, but basically I
cut the ribs tips to a semi circle. This takes you back one rivet top and
bottom from the original rib flanges. I left a tab with a single rivet hole
at the leading edge, then added little 0.030" clips at the 45* points to
support the new LE skin. Then just trim and rivet in a new semi-circular
piece of 020 round the LE. Took 4 hours a side.
I may try the same trick on the rudder. It also has a tendency not to
return to neutral, but there's quite a bit more friction in the rudders due
to all those fairleads.
Another mod I'm considering is decreasing the incidence on the stab. With
floats, I'm flying around with 5* or more of up elevator all the time, which
can't be good for drag. I figure I could get away with a 1/8" shim under
the rear stab support brackets without having to rework the fiberglass
fairing. But getting at the bolts that secure the stab is a pain - pretty
well have to remove the stab. Maybe I'll take the risk and build the shims
in permanantly when I have the stab off for painting.
Al
-----------------------------------------------------------------
List archives located at: https://mail.dcsol.com/login
username "rebel" password "builder"
Unsubscribe: rebel-builders-unsubscribe@dcsol.com
List administrator: mike.davis@dcsol.com
-----------------------------------------------------------------
cut the ribs tips to a semi circle. This takes you back one rivet top and
bottom from the original rib flanges. I left a tab with a single rivet hole
at the leading edge, then added little 0.030" clips at the 45* points to
support the new LE skin. Then just trim and rivet in a new semi-circular
piece of 020 round the LE. Took 4 hours a side.
I may try the same trick on the rudder. It also has a tendency not to
return to neutral, but there's quite a bit more friction in the rudders due
to all those fairleads.
Another mod I'm considering is decreasing the incidence on the stab. With
floats, I'm flying around with 5* or more of up elevator all the time, which
can't be good for drag. I figure I could get away with a 1/8" shim under
the rear stab support brackets without having to rework the fiberglass
fairing. But getting at the bolts that secure the stab is a pain - pretty
well have to remove the stab. Maybe I'll take the risk and build the shims
in permanantly when I have the stab off for painting.
Al
-----------------------------------------------------------------
List archives located at: https://mail.dcsol.com/login
username "rebel" password "builder"
Unsubscribe: rebel-builders-unsubscribe@dcsol.com
List administrator: mike.davis@dcsol.com
-----------------------------------------------------------------
-
Mike Betti
Modified Elite Elevator
Al,
Nice to see you working out the bugs for my homebuilt. Also interested in
pictures.
Thanks for sharing with the group,
Mike Betti
771E
----- Original Message -----
From: "Scott Aldrich" <sa@mwutah.com>
To: <rebel-builders@dcsol.com>
Sent: Tuesday, November 08, 2005 5:21 PM
Subject: RE: Modified Elite Elevator
-----------------------------------------------------------------
List archives located at: https://mail.dcsol.com/login
username "rebel" password "builder"
Unsubscribe: rebel-builders-unsubscribe@dcsol.com
List administrator: mike.davis@dcsol.com
-----------------------------------------------------------------
Nice to see you working out the bugs for my homebuilt. Also interested in
pictures.
Thanks for sharing with the group,
Mike Betti
771E
----- Original Message -----
From: "Scott Aldrich" <sa@mwutah.com>
To: <rebel-builders@dcsol.com>
Sent: Tuesday, November 08, 2005 5:21 PM
Subject: RE: Modified Elite Elevator
Al, pictures of the tips?
Thanks,
Scott
-----Original Message-----
From: mike.davis@dcsol.com [mailto:mike.davis@dcsol.com] On Behalf Of Alan
Hepburn
Sent: Tuesday, November 08, 2005 3:51 PM
To: rebel-builders@dcsol.com
Subject: Modified Elite Elevator
I tried out my modifications to the Elite elevator spades this morning.
The
following information pertains to an elevator with spades aleady cut down
to
4 1/4" wide. Also, the airplane is on amphib. floats.
Before modification of the spade leading edge, the cross section was per
Murphy's design - i.e. rectangular with rounded corners. In this
configuration, when pulsed downwards in cruise flight, the aircraft
continues to pitch downwards - i.e. the airplane demonstrates negative
dynamic stability in pitch, stick free. This pilot ran out of courage
before the airplane ran out of forward pitching tendancy. Everything
happens quite slowly, so is readily controllable hands on. In fact,
pilots
don't tend to notice the behaviour until it's pointed out to them.
The modification consists of changing the spade leading edge cross section
to a semi circle. The resulting handling is certainly an improvement.
The
pitch stability is now just positively stable. When you pulse the stick
forward and release it, the nose stays where it is for a second or so - it
may even pitch a degree or so further down - then very slowly returns to
the
trimmed attitude. This takes about 17 seconds. I'd rather see it take
something like 3 - 5 seconds. However, I'd say the change is well worth
making. If anybody has any other ideas to further improve the situation,
I'd like to hear them.
Al
Elite #587
-----------------------------------------------------------------
List archives located at: https://www.dcsol.com/login
username "rebel" password "builder"
Subscription services located at:
https://www.dcsol.com/public/code/html-subscribe.htm
List administrator: mike.davis@dcsol.com
-----------------------------------------------------------------
-----------------------------------------------------------------
List archives located at: https://www.dcsol.com/login
username "rebel" password "builder"
Subscription services located at:
https://www.dcsol.com/public/code/html-subscribe.htm
List administrator: mike.davis@dcsol.com
-----------------------------------------------------------------
-----------------------------------------------------------------
List archives located at: https://mail.dcsol.com/login
username "rebel" password "builder"
Unsubscribe: rebel-builders-unsubscribe@dcsol.com
List administrator: mike.davis@dcsol.com
-----------------------------------------------------------------
-
Alan Hepburn
Modified Elite Elevator
No, same weight. The weight is not critical. Flutter is not a major
problem at 100 kts. People balance them on a knife edge, then proceed to
paint afterwards, or even add the trim servo!
-----------------------------------------------------------------
List archives located at: https://mail.dcsol.com/login
username "rebel" password "builder"
Unsubscribe: rebel-builders-unsubscribe@dcsol.com
List administrator: mike.davis@dcsol.com
-----------------------------------------------------------------
problem at 100 kts. People balance them on a knife edge, then proceed to
paint afterwards, or even add the trim servo!
-----------------------------------------------------------------
List archives located at: https://mail.dcsol.com/login
username "rebel" password "builder"
Unsubscribe: rebel-builders-unsubscribe@dcsol.com
List administrator: mike.davis@dcsol.com
-----------------------------------------------------------------
-
cosmedi
Modified Elite Elevator
Al,
Apart from been a pain in the butt, could you place pictures as well as a detailed schematic diagram of meaurements of the changes. Many thanks. Also thanks for been the test pilot!!!!
Greg Elite 724
-----------------------------------------------------------------
List archives located at: https://mail.dcsol.com/login
username "rebel" password "builder"
Unsubscribe: rebel-builders-unsubscribe@dcsol.com
List administrator: mike.davis@dcsol.com
-----------------------------------------------------------------
Apart from been a pain in the butt, could you place pictures as well as a detailed schematic diagram of meaurements of the changes. Many thanks. Also thanks for been the test pilot!!!!
Greg Elite 724
-----------------------------------------------------------------
List archives located at: https://mail.dcsol.com/login
username "rebel" password "builder"
Unsubscribe: rebel-builders-unsubscribe@dcsol.com
List administrator: mike.davis@dcsol.com
-----------------------------------------------------------------
-
Bob Patterson
Modified Elite Elevator
Thanks for the vindication, Al !!
It's been a long time coming, but now others will be
a lot safer, because of your efforts !!!
I would hope that everyone would follow your example - including
the Moose builders... This IS a very worthwhile mod !
I believe that the rounded tip would help the rudder as well.
It's good to reduce the friction in the system as much as possible,
and it is also very important to have AT LEAST the mass balance
suggested by the factory (75%). As someone who has suffered
elevator flutter, right down to stall speed - it CAN happen at
ANY speed, and mass balance, and rigidity of the tip horns
IS very important !!
We added a wide strip of .032 most of the way around the
inside of the elevator & rudder tips on the Rebel. The original
fiberglass was thin and 'wiggly' - the extra stiffness, and
extra weight, helped a lot to prevent oscillation & twisting.
The beefups to the end ribs also help, and may have been partly
necessary because of the original flexiness ...
......bobp
-------------------------------orig.-------------------------
On Tuesday 08 November 2005 05:51 pm, Alan Hepburn wrote:
down to 4 1/4" wide. Also, the airplane is on amphib. floats.
configuration, when pulsed downwards in cruise flight, the aircraft
continues to pitch downwards - i.e. the airplane demonstrates negative
dynamic stability in pitch, stick free. This pilot ran out of courage
before the airplane ran out of forward pitching tendancy. Everything
happens quite slowly, so is readily controllable hands on. In fact, pilots
don't tend to notice the behaviour until it's pointed out to them.
pitch stability is now just positively stable. When you pulse the stick
forward and release it, the nose stays where it is for a second or so - it
may even pitch a degree or so further down - then very slowly returns to
the trimmed attitude. This takes about 17 seconds. I'd rather see it take
something like 3 - 5 seconds. However, I'd say the change is well worth
making. If anybody has any other ideas to further improve the situation,
I'd like to hear them.
-----------------------------------------------------------------
List archives located at: https://mail.dcsol.com/login
username "rebel" password "builder"
Unsubscribe: rebel-builders-unsubscribe@dcsol.com
List administrator: mike.davis@dcsol.com
-----------------------------------------------------------------
It's been a long time coming, but now others will be
a lot safer, because of your efforts !!!
I would hope that everyone would follow your example - including
the Moose builders... This IS a very worthwhile mod !
I believe that the rounded tip would help the rudder as well.
It's good to reduce the friction in the system as much as possible,
and it is also very important to have AT LEAST the mass balance
suggested by the factory (75%). As someone who has suffered
elevator flutter, right down to stall speed - it CAN happen at
ANY speed, and mass balance, and rigidity of the tip horns
IS very important !!
We added a wide strip of .032 most of the way around the
inside of the elevator & rudder tips on the Rebel. The original
fiberglass was thin and 'wiggly' - the extra stiffness, and
extra weight, helped a lot to prevent oscillation & twisting.
The beefups to the end ribs also help, and may have been partly
necessary because of the original flexiness ...
......bobp
-------------------------------orig.-------------------------
On Tuesday 08 November 2005 05:51 pm, Alan Hepburn wrote:
The following information pertains to an elevator with spades aleady cutI tried out my modifications to the Elite elevator spades this morning.
down to 4 1/4" wide. Also, the airplane is on amphib. floats.
Murphy's design - i.e. rectangular with rounded corners. In thisBefore modification of the spade leading edge, the cross section was per
configuration, when pulsed downwards in cruise flight, the aircraft
continues to pitch downwards - i.e. the airplane demonstrates negative
dynamic stability in pitch, stick free. This pilot ran out of courage
before the airplane ran out of forward pitching tendancy. Everything
happens quite slowly, so is readily controllable hands on. In fact, pilots
don't tend to notice the behaviour until it's pointed out to them.
to a semi circle. The resulting handling is certainly an improvement. TheThe modification consists of changing the spade leading edge cross section
pitch stability is now just positively stable. When you pulse the stick
forward and release it, the nose stays where it is for a second or so - it
may even pitch a degree or so further down - then very slowly returns to
the trimmed attitude. This takes about 17 seconds. I'd rather see it take
something like 3 - 5 seconds. However, I'd say the change is well worth
making. If anybody has any other ideas to further improve the situation,
I'd like to hear them.
Al
Elite #587
-----------------------------------------------------------------
List archives located at: https://www.dcsol.com/login
username "rebel" password "builder"
Subscription services located at:
https://www.dcsol.com/public/code/html-subscribe.htm
List administrator: mike.davis@dcsol.com
-----------------------------------------------------------------
-----------------------------------------------------------------
List archives located at: https://mail.dcsol.com/login
username "rebel" password "builder"
Unsubscribe: rebel-builders-unsubscribe@dcsol.com
List administrator: mike.davis@dcsol.com
-----------------------------------------------------------------
-
Mike Betti
Modified Elite Elevator
Al,
During your elevator mod, were the weights in the way or have to be trimmed?
Mike Betti
771E
----- Original Message -----
From: "Alan Hepburn" <ahepburn@renc.igs.net>
To: <rebel-builders@dcsol.com>
Sent: Tuesday, November 08, 2005 7:13 PM
Subject: Re: Modified Elite Elevator
-----------------------------------------------------------------
List archives located at: https://mail.dcsol.com/login
username "rebel" password "builder"
Unsubscribe: rebel-builders-unsubscribe@dcsol.com
List administrator: mike.davis@dcsol.com
-----------------------------------------------------------------
During your elevator mod, were the weights in the way or have to be trimmed?
Mike Betti
771E
----- Original Message -----
From: "Alan Hepburn" <ahepburn@renc.igs.net>
To: <rebel-builders@dcsol.com>
Sent: Tuesday, November 08, 2005 7:13 PM
Subject: Re: Modified Elite Elevator
I'll download some pics once I get the chance to take them, but basically
I
cut the ribs tips to a semi circle. This takes you back one rivet top and
bottom from the original rib flanges. I left a tab with a single rivet
hole
at the leading edge, then added little 0.030" clips at the 45* points to
support the new LE skin. Then just trim and rivet in a new semi-circular
piece of 020 round the LE. Took 4 hours a side.
I may try the same trick on the rudder. It also has a tendency not to
return to neutral, but there's quite a bit more friction in the rudders
due
to all those fairleads.
Another mod I'm considering is decreasing the incidence on the stab. With
floats, I'm flying around with 5* or more of up elevator all the time,
which
can't be good for drag. I figure I could get away with a 1/8" shim under
the rear stab support brackets without having to rework the fiberglass
fairing. But getting at the bolts that secure the stab is a pain - pretty
well have to remove the stab. Maybe I'll take the risk and build the
shims
in permanantly when I have the stab off for painting.
Al
-----------------------------------------------------------------
List archives located at: https://www.dcsol.com/login
username "rebel" password "builder"
Subscription services located at:
https://www.dcsol.com/public/code/html-subscribe.htm
List administrator: mike.davis@dcsol.com
-----------------------------------------------------------------
-----------------------------------------------------------------
List archives located at: https://mail.dcsol.com/login
username "rebel" password "builder"
Unsubscribe: rebel-builders-unsubscribe@dcsol.com
List administrator: mike.davis@dcsol.com
-----------------------------------------------------------------
-
Alan Hepburn
Modified Elite Elevator
Mike:
I take it you're talking the semi-circular tips. If so, the answer is "No".
I'd forgotten what shape the weights were, but when I cut it open I was
pleased to discover that they taper from about 1 1/2" to maybe 3/4" at the
tip. So no interference.
Al
-----------------------------------------------------------------
List archives located at: https://mail.dcsol.com/login
username "rebel" password "builder"
Unsubscribe: rebel-builders-unsubscribe@dcsol.com
List administrator: mike.davis@dcsol.com
-----------------------------------------------------------------
I take it you're talking the semi-circular tips. If so, the answer is "No".
I'd forgotten what shape the weights were, but when I cut it open I was
pleased to discover that they taper from about 1 1/2" to maybe 3/4" at the
tip. So no interference.
Al
-----------------------------------------------------------------
List archives located at: https://mail.dcsol.com/login
username "rebel" password "builder"
Unsubscribe: rebel-builders-unsubscribe@dcsol.com
List administrator: mike.davis@dcsol.com
-----------------------------------------------------------------
-
Mike Betti
Modified Elite Elevator
Ok thanks Al,
How about some pictures of your mod? I think I know what you did, but a
picture would help.
Mike
----- Original Message -----
From: "Alan Hepburn" <ahepburn@renc.igs.net>
To: <rebel-builders@dcsol.com>
Sent: Friday, December 16, 2005 8:27 PM
Subject: Re: Modified Elite Elevator
-----------------------------------------------------------------
List archives located at: https://mail.dcsol.com/login
username "rebel" password "builder"
Unsubscribe: rebel-builders-unsubscribe@dcsol.com
List administrator: mike.davis@dcsol.com
-----------------------------------------------------------------
How about some pictures of your mod? I think I know what you did, but a
picture would help.
Mike
----- Original Message -----
From: "Alan Hepburn" <ahepburn@renc.igs.net>
To: <rebel-builders@dcsol.com>
Sent: Friday, December 16, 2005 8:27 PM
Subject: Re: Modified Elite Elevator
Mike:
I take it you're talking the semi-circular tips. If so, the answer is
"No".
I'd forgotten what shape the weights were, but when I cut it open I was
pleased to discover that they taper from about 1 1/2" to maybe 3/4" at the
tip. So no interference.
Al
-----------------------------------------------------------------
List archives located at: https://www.dcsol.com/login
username "rebel" password "builder"
Subscription services located at:
https://www.dcsol.com/public/code/html-subscribe.htm
List administrator: mike.davis@dcsol.com
-----------------------------------------------------------------
-----------------------------------------------------------------
List archives located at: https://mail.dcsol.com/login
username "rebel" password "builder"
Unsubscribe: rebel-builders-unsubscribe@dcsol.com
List administrator: mike.davis@dcsol.com
-----------------------------------------------------------------
-
Mike Davis
Modified Elite Elevator
There are photos in the E-Modifications file area Mike.
Mike
----- Original Message -----
From: "Mike Betti" <mbetti@up.net>
To: <rebel-builders@dcsol.com>
Sent: Friday, December 16, 2005 6:18 PM
Subject: Re: Modified Elite Elevator
-----------------------------------------------------------------
List archives located at: https://mail.dcsol.com/login
username "rebel" password "builder"
Unsubscribe: rebel-builders-unsubscribe@dcsol.com
List administrator: mike.davis@dcsol.com
-----------------------------------------------------------------
Mike
----- Original Message -----
From: "Mike Betti" <mbetti@up.net>
To: <rebel-builders@dcsol.com>
Sent: Friday, December 16, 2005 6:18 PM
Subject: Re: Modified Elite Elevator
Ok thanks Al,
How about some pictures of your mod? I think I know what you did, but a
picture would help.
Mike
----- Original Message -----
From: "Alan Hepburn" <ahepburn@renc.igs.net>
To: <rebel-builders@dcsol.com>
Sent: Friday, December 16, 2005 8:27 PM
Subject: Re: Modified Elite Elevator
Mike:
I take it you're talking the semi-circular tips. If so, the answer is
"No".
I'd forgotten what shape the weights were, but when I cut it open I was
pleased to discover that they taper from about 1 1/2" to maybe 3/4" at
the
tip. So no interference.
Al
-----------------------------------------------------------------
List archives located at: https://mail.dcsol.com/login
username "rebel" password "builder"
Unsubscribe: rebel-builders-unsubscribe@dcsol.com
List administrator: mike.davis@dcsol.com
-----------------------------------------------------------------
-
Mike Betti
Modified Elite Elevator
Thanks Mike,
I been looking in the E-elevator.
Mike
----- Original Message -----
From: "Mike Davis" <mike.davis@dcsol.com>
To: <rebel-builders@dcsol.com>
Sent: Friday, December 16, 2005 9:39 PM
Subject: Re: Modified Elite Elevator
-----------------------------------------------------------------
List archives located at: https://mail.dcsol.com/login
username "rebel" password "builder"
Unsubscribe: rebel-builders-unsubscribe@dcsol.com
List administrator: mike.davis@dcsol.com
-----------------------------------------------------------------
I been looking in the E-elevator.
Mike
----- Original Message -----
From: "Mike Davis" <mike.davis@dcsol.com>
To: <rebel-builders@dcsol.com>
Sent: Friday, December 16, 2005 9:39 PM
Subject: Re: Modified Elite Elevator
There are photos in the E-Modifications file area Mike.
Mike
----- Original Message -----
From: "Mike Betti" <mbetti@up.net>
To: <rebel-builders@dcsol.com>
Sent: Friday, December 16, 2005 6:18 PM
Subject: Re: Modified Elite Elevator
Ok thanks Al,
How about some pictures of your mod? I think I know what you did, but a
picture would help.
Mike
----- Original Message -----
From: "Alan Hepburn" <ahepburn@renc.igs.net>
To: <rebel-builders@dcsol.com>
Sent: Friday, December 16, 2005 8:27 PM
Subject: Re: Modified Elite Elevator
Mike:
I take it you're talking the semi-circular tips. If so, the answer is
"No".
I'd forgotten what shape the weights were, but when I cut it open I was
pleased to discover that they taper from about 1 1/2" to maybe 3/4" at
the
tip. So no interference.
Al
-----------------------------------------------------------------
List archives located at: https://www.dcsol.com/login
username "rebel" password "builder"
Subscription services located at:
https://www.dcsol.com/public/code/html-subscribe.htm
List administrator: mike.davis@dcsol.com
-----------------------------------------------------------------
-----------------------------------------------------------------
List archives located at: https://mail.dcsol.com/login
username "rebel" password "builder"
Unsubscribe: rebel-builders-unsubscribe@dcsol.com
List administrator: mike.davis@dcsol.com
-----------------------------------------------------------------
