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To: <murphy-rebel@dcsol.com> (Murphy Rebel Builders List)
From: Bob Patterson <bob.patterson@canrem.com>
Subject: Re: New Aluminum tail spring
Message-Id: <E10yRUK-0000zP-00@mail4.toronto.istar.net>
Date: Sun, 27 Jun 1999 22:49:40 -0400


Did you have a composite tail spring originally, Walter ?? If you are
using the standard Murphy tailwheel, you can shorten that spring and use
it with no problems. We have used one for 8 years - finally replaced it
last year, when it started to delaminate..... (After only 8 years outside
in the sun, and about 900 hours of landing on sometimes rough grass strips,
and rougher asphalt ones ! ;-) )

We were able to trade the new metal spring for another composite spring,
which was slightly thicker than the original, so just ground it down to fit
the bracket.

Negative dihedral is definitely NOT a good idea - could effect stability,
handling, and strength. You could remove or thin down the spacer above
the spring (assuming you have one ...) - this would be the easiest way.
I have seen folks use a thin piece of rubber instead of the upper spacer -
cut from an inner tube, or a thin tire sidewall. Probably not a bad
idea - gives a little extra shock absorbing ....

The composite springs are probably not the best choice if you are
using a larger, heavier tailwheel, like the Scott 3200 or Maule (if you
can, choose the Scott - Maules tend to wear & shimmy MUCH sooner :-( ).
Scott makes a very nice, smaller tailwheel, the 2200, which is a good fit
for the Rebel, as well, but not as common as the 3200, and not much cheaper,
either. Many builders who are using heavier engines (read O-320's) are
choosing the Scott 3200 because it adds at least 8 lb. right out on the
tail, which helps the C of G.


.....bobp

-----------------------------orig.-----------------------------------------
At 12:49 PM 6/27/99 -0700, you wrote:

I have one of the earlier Rebels with the old thinner,
weaker tail springs, and upgraded to the latest stronger
tail spring along with the associated spacers, etc. I was
doing some final checks and adjustments of my controls, when
I noticed that the horizontal stabilizers had a slight
negative dihedral (about an inch). I then realized it was
due to the thicker tail spring and spacers which lowered my
tail skid attach bracket by about 5/16 of an inch. To get my
stabs level again, I need to redo my tail struts longer, or
put in a new tail skid attach bracket and space out the
strut attach holes slightly to fit the existing tail struts.

I am just wondering if anyone else has run into this, and
what their solution was. Does 1 or 2 inches of negative
dihedral in the tail make any difference? I plan to put the
plane on floats after a year or so, and can then go back to
the original tail spring set-up.

*----------------------------------------------------*
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between builders and owners of Murphy Rebel aircraft.
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http://www.dcsol.com/murphy-rebel/lists/default.htm
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Date: Sun, 27 Jun 1999 21:04:12 -0700
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To: " (Murphy Rebel Builders List)" <murphy-rebel@dcsol.com>
Subject: Re: New Aluminum tail spring
References: <E10yRUK-0000zP-00@mail4.toronto.istar.net>
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Bob, my Rebel had an aluminum tail spring which was even before the
composite
one. My serial # is 107R. With the newer replacement tail spring, an
additional
spacer TS-7 was added on top of the extra thickness of the new tail spring,
which is what lowered the strut attach bracket. I am not sure what purpose
it
served, so I removed it, leaving only the original TS-2 spacer in place.
That
gained back some altitude on the strut bracket, and now I have only 1/4
inch
negative dihedral. Do you think this is still a problem? I could replace the
TS-2 with another spacer that is 1/8 inch less thick, and that would bring
me
back to the original stab height. I am using the Murphy tail wheel modified
to
kick out on a sharp turn. I hope it works. I am almost ready to do a weight
and
balance, so might still go for the heavier Scott tail wheel if I have a
problem.
I am using an O320.

Bob Patterson wrote:

Did you have a composite tail spring originally, Walter ?? If you are
using the standard Murphy tailwheel, you can shorten that spring and use
it with no problems. We have used one for 8 years - finally replaced it
last year, when it started to delaminate..... (After only 8 years outside
in the sun, and about 900 hours of landing on sometimes rough grass

strips,

and rougher asphalt ones ! ;-) )

We were able to trade the new metal spring for another composite

spring,

which was slightly thicker than the original, so just ground it down to

fit

the bracket.

Negative dihedral is definitely NOT a good idea - could effect

stability,

handling, and strength. You could remove or thin down the spacer above
the spring (assuming you have one ...) - this would be the easiest way.
I have seen folks use a thin piece of rubber instead of the upper spacer -
cut from an inner tube, or a thin tire sidewall. Probably not a bad
idea - gives a little extra shock absorbing ....

The composite springs are probably not the best choice if you are
using a larger, heavier tailwheel, like the Scott 3200 or Maule (if you
can, choose the Scott - Maules tend to wear & shimmy MUCH sooner :-( ).
Scott makes a very nice, smaller tailwheel, the 2200, which is a good fit
for the Rebel, as well, but not as common as the 3200, and not much

cheaper,

either. Many builders who are using heavier engines (read O-320's) are
choosing the Scott 3200 because it adds at least 8 lb. right out on the
tail, which helps the C of G.


.....bobp

-----------------------------orig.----------------------------------------

-

At 12:49 PM 6/27/99 -0700, you wrote:

I have one of the earlier Rebels with the old thinner,
weaker tail springs, and upgraded to the latest stronger
tail spring along with the associated spacers, etc. I was
doing some final checks and adjustments of my controls, when
I noticed that the horizontal stabilizers had a slight
negative dihedral (about an inch). I then realized it was
due to the thicker tail spring and spacers which lowered my
tail skid attach bracket by about 5/16 of an inch. To get my
stabs level again, I need to redo my tail struts longer, or
put in a new tail skid attach bracket and space out the
strut attach holes slightly to fit the existing tail struts.

I am just wondering if anyone else has run into this, and
what their solution was. Does 1 or 2 inches of negative
dihedral in the tail make any difference? I plan to put the
plane on floats after a year or so, and can then go back to
the original tail spring set-up.

*----------------------------------------------------*
The Murphy Rebel Builders List is for the discussion
between builders and owners of Murphy Rebel aircraft.
Archives located at:
http://www.dcsol.com/murphy-rebel/lists/default.htm
*----------------------------------------------------*

*----------------------------------------------------*
The Murphy Rebel Builders List is for the discussion
between builders and owners of Murphy Rebel aircraft.
Archives located at:
http://www.dcsol.com/murphy-rebel/lists/default.htm
*----------------------------------------------------*

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To: <murphy-rebel@dcsol.com> (Murphy Rebel Builders List)
From: Bob Patterson <bob.patterson@canrem.com>
Subject: Re: New Aluminum tail spring
Message-Id: <E10yodK-00028J-00@mail4.toronto.istar.net>
Date: Mon, 28 Jun 1999 23:32:30 -0400


Happy to help, anytime !! I'm only a 'builder helper' out here, though, and
I'm NOT always right - just another opinion to add to those you've already
collected ..... hope it helps !! The factory is always the final authority.

Many years ago, the tail springs on our Piper J-4A used to break off
regularly - I'd just take out the pieces, clamp the bolts tight on a spacer,
hold the brakes to raise the tail, and take off to fly down to our mechanic
to get it fixed !! Hold the brakes on landing, to keep the tail up, then let
it down gently.... We eventually went to an automobile spring shop and
had a half-dozen sets made up, slightly heavier material - no more problems
!
(Not quite 'certified' material, but it worked !) Certainly stirred things
up when I made a low pass before leaving, waving the tailwheel, to let the
guys who just arrived know where & why I was going - they couldn't figure
out how I climbed out & removed the tailwheel in flight !!! :-)

The spacer would be the same width, just thinner - you <could> just grind
down the present one, to leave room for a bit of inner tube, clamped
tightly...
The thicker spacer might have been needed because of the bent-in curve of
some springs - to clamp them without exerting a bending load just from the
way they were fastened.... Most of this stuff is just common sense & good
judgement - if it looks reasonable, and is secure, with no built-in stesses,
it's probably OK. If you're tightening up the bolts & bending the spring
just to get them tight, that's NOT "a good thing"(tm).... :-)

Sounds like you've done everything right, up front ! If needed, some of
the builders have moved the battery to the back of the firewall, on the
passenger side, above the pedals. This involves a special hinge on the
back of the box, but does move the battery back a fair bit. We have one
builder here with the Sky-tec starter, who used the small, square (about 4")
motorcycle battery, on the front of the firewall. It cranks over fast enough
to taxi !!! You don't need a LOT of battery with those geared starters !
These batteries are small, LIGHT, and cheap - we've used them in our Rebel
for 8 years - they usually last 2 or 3 years (the Canadian winters kill 'em
!).

I suspect that your C of G will come out very close to being OK -
Good Luck !!

.....bobp

--------------------------------orig.---------------------------------------
-
At 07:13 PM 6/28/99 -0700, you wrote:

Thanks Bob. It really helps to have "field" information. I sent a message

to MAM on

this issue, too, but haven't got a reply yet.

Using a thinner spacer would be the best solution, if it can handle the

load. I

don't understand why they added the additional spacer, TS-7, though, if not

for

added strength. I can see why the rubber would be a good idea for

cushioning the

impacts, but it would again lower the tail strut attach bracket which then

gives me

that undesirable negative dihedral.

I am using a lightweight Skytech starter and a Sprint alternator, along

with the

Warp Drive prop. Also, my firewall is cut back 3 inches. So I have taken

whatever

steps I know to reduce forward weight. However, I still have my battery

mounted on

the firewall, and I realize I may be dreaming, if I think that can remain.

I just

got my newly upholstered seats back, so am almost ready for that big C of G

test.

Thanks again for your help.

Bob Patterson wrote:

I had almost forgotten the earlier aluminum springs - we used one for

a

season. It went flat after repeated bumps .... (aluminum is not a great
material for 'springs' :-) )

If you can use a thinner spacer, that would be great. As I mentioned,
some have added a thin piece of rubber between the spacer and the spring.
The spacer is only to get a good angle for the spring, and to distribute
the loads from the spring to the tail post over a larger area, so making
it thinner shouldn't hurt.

If you do go to the Scott tailwheel, you will likely find that it
doesn't fit the spring. You can grind the spring a bit, and there are
spacer blocks available to help with the fit. Have a look through the
archives of this list - I think someone described these a few months ago.
I think Scott make different size attachment fittings.

You can move your battery back to adjust the C of G - several here
have used a long, narrow battery (about 3 1/2" thick, by about 10 - 11"
long). These can be positioned on the right side of the fuselage, between
the bulkheads, leaving the floor open for sleeping. Just move it back

until

you get the desired position....

The Murphy kick-out tailwheel works GREAT, once it is broken in. Be
sure to grease it regularly, especially the pin at the top. There should
be a grease fitting there for it, but it's not in the design, so you just
have to stuff a glob of grease into the underside with your finger, at
least once a month....

If you haven't already, you can save a LOT of weight up front by

going

to the B & C lightweight starter, and a lightweight alternator, (over 30

lbs),

as well as the (now-almost-standard) 3 blade Warp Drive 72 inch prop with
17" of metal on the leading edge, and SQUARE tips !

Sounds like you're making good progress - keep at it. It's worth it

!!

.....bobp

-----------------------------------orig.---------------------------------

-

At 09:04 PM 6/27/99 -0700, you wrote:

Bob, my Rebel had an aluminum tail spring which was even before the

composite

one. My serial # is 107R. With the newer replacement tail spring, an

additional

spacer TS-7 was added on top of the extra thickness of the new tail

spring,

which is what lowered the strut attach bracket. I am not sure what

purpose it

served, so I removed it, leaving only the original TS-2 spacer in place.

That

gained back some altitude on the strut bracket, and now I have only 1/4

inch

negative dihedral. Do you think this is still a problem? I could replace

the

TS-2 with another spacer that is 1/8 inch less thick, and that would

bring me

back to the original stab height. I am using the Murphy tail wheel

modified to

kick out on a sharp turn. I hope it works. I am almost ready to do a

weight and

balance, so might still go for the heavier Scott tail wheel if I have a

problem.

I am using an O320.

Bob Patterson wrote:

are

use

it

outside

strips,

spring,

to fit

stability,

way.

spacer -

you

:-( ).

fit

cheaper,

the

-----------------------------orig.-----------------------------------------

*----------------------------------------------------*
The Murphy Rebel Builders List is for the discussion
between builders and owners of Murphy Rebel aircraft.
Archives located at:
http://www.dcsol.com/murphy-rebel/lists/default.htm
*----------------------------------------------------*

*----------------------------------------------------*
The Murphy Rebel Builders List is for the discussion
between builders and owners of Murphy Rebel aircraft.
Archives located at:
http://www.dcsol.com/murphy-rebel/lists/default.htm
*----------------------------------------------------*

*----------------------------------------------------*
The Murphy Rebel Builders List is for the discussion
between builders and owners of Murphy Rebel aircraft.
Archives located at:
http://www.dcsol.com/murphy-rebel/lists/default.htm
*----------------------------------------------------*

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To: <murphy-rebel@dcsol.com> (Murphy Rebel Builders List)
From: Brian Cross <rebelair@idirect.com>
Subject: Re: New Aluminum tail spring
In-Reply-To: <E10yiw8-000346-00@mail4.toronto.istar.net>
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Hi Bob

I think that I mentioned that the Warp Drive factory still recommends
square tips for float operation but the tapered tips for wheel ops.

Hope to find out soon myself what the difference is. We should have a good
basis of comparison as Ron Barber is about ready to fly with a similar
setup with square tips and myself with tapered tips. We both have 'modern'
0320 engines. What a marvel of 1930's technology they are!

Regards

Brian #328R


At 05:27 PM 28/06/99 -0400, you wrote:

I had almost forgotten the earlier aluminum springs - we used one for a
season. It went flat after repeated bumps .... (aluminum is not a great
material for 'springs' :-) )

If you can use a thinner spacer, that would be great. As I mentioned,
some have added a thin piece of rubber between the spacer and the spring.
The spacer is only to get a good angle for the spring, and to distribute
the loads from the spring to the tail post over a larger area, so making
it thinner shouldn't hurt.

If you do go to the Scott tailwheel, you will likely find that it
doesn't fit the spring. You can grind the spring a bit, and there are
spacer blocks available to help with the fit. Have a look through the
archives of this list - I think someone described these a few months ago.
I think Scott make different size attachment fittings.

You can move your battery back to adjust the C of G - several here
have used a long, narrow battery (about 3 1/2" thick, by about 10 - 11"
long). These can be positioned on the right side of the fuselage, between
the bulkheads, leaving the floor open for sleeping. Just move it back until
you get the desired position....

The Murphy kick-out tailwheel works GREAT, once it is broken in. Be
sure to grease it regularly, especially the pin at the top. There should
be a grease fitting there for it, but it's not in the design, so you just
have to stuff a glob of grease into the underside with your finger, at
least once a month....

If you haven't already, you can save a LOT of weight up front by going
to the B & C lightweight starter, and a lightweight alternator, (over 30

lbs),

as well as the (now-almost-standard) 3 blade Warp Drive 72 inch prop with
17" of metal on the leading edge, and SQUARE tips !

Sounds like you're making good progress - keep at it. It's worth it !!

.....bobp

-----------------------------------orig.----------------------------------
At 09:04 PM 6/27/99 -0700, you wrote:

Bob, my Rebel had an aluminum tail spring which was even before the

composite

one. My serial # is 107R. With the newer replacement tail spring, an

additional

spacer TS-7 was added on top of the extra thickness of the new tail

spring,

which is what lowered the strut attach bracket. I am not sure what

purpose it

served, so I removed it, leaving only the original TS-2 spacer in place.

That

gained back some altitude on the strut bracket, and now I have only 1/4

inch

negative dihedral. Do you think this is still a problem? I could replace

the

TS-2 with another spacer that is 1/8 inch less thick, and that would

bring me

back to the original stab height. I am using the Murphy tail wheel

modified to

kick out on a sharp turn. I hope it works. I am almost ready to do a

weight and

balance, so might still go for the heavier Scott tail wheel if I have a

problem.

I am using an O320.

Bob Patterson wrote:

Did you have a composite tail spring originally, Walter ?? If you are
using the standard Murphy tailwheel, you can shorten that spring and use
it with no problems. We have used one for 8 years - finally replaced it
last year, when it started to delaminate..... (After only 8 years

outside

in the sun, and about 900 hours of landing on sometimes rough grass

strips,

and rougher asphalt ones ! ;-) )

We were able to trade the new metal spring for another composite

spring,

which was slightly thicker than the original, so just ground it down to

fit

the bracket.

Negative dihedral is definitely NOT a good idea - could effect

stability,

handling, and strength. You could remove or thin down the spacer above
the spring (assuming you have one ...) - this would be the easiest way.
I have seen folks use a thin piece of rubber instead of the upper

spacer -

cut from an inner tube, or a thin tire sidewall. Probably not a bad
idea - gives a little extra shock absorbing ....

The composite springs are probably not the best choice if you are
using a larger, heavier tailwheel, like the Scott 3200 or Maule (if you
can, choose the Scott - Maules tend to wear & shimmy MUCH sooner :-( ).
Scott makes a very nice, smaller tailwheel, the 2200, which is a good

fit

for the Rebel, as well, but not as common as the 3200, and not much

cheaper,

either. Many builders who are using heavier engines (read O-320's) are
choosing the Scott 3200 because it adds at least 8 lb. right out on the
tail, which helps the C of G.


.....bobp

-----------------------------orig.-----------------------------------------

At 12:49 PM 6/27/99 -0700, you wrote: *----------------------------------------------------*
The Murphy Rebel Builders List is for the discussion
between builders and owners of Murphy Rebel aircraft.
Archives located at:
http://www.dcsol.com/murphy-rebel/lists/default.htm
*----------------------------------------------------*

*----------------------------------------------------*
The Murphy Rebel Builders List is for the discussion
between builders and owners of Murphy Rebel aircraft.
Archives located at:
http://www.dcsol.com/murphy-rebel/lists/default.htm
*----------------------------------------------------*

*----------------------------------------------------*
The Murphy Rebel Builders List is for the discussion
between builders and owners of Murphy Rebel aircraft.
Archives located at:
http://www.dcsol.com/murphy-rebel/lists/default.htm
*----------------------------------------------------*

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To: <murphy-rebel@dcsol.com> (Murphy Rebel Builders List)
From: Bob Patterson <bob.patterson@canrem.com>
Subject: Re: New Aluminum tail spring
Message-Id: <E10yiw8-000346-00@mail4.toronto.istar.net>
Date: Mon, 28 Jun 1999 17:27:33 -0400


I had almost forgotten the earlier aluminum springs - we used one for a
season. It went flat after repeated bumps .... (aluminum is not a great
material for 'springs' :-) )

If you can use a thinner spacer, that would be great. As I mentioned,
some have added a thin piece of rubber between the spacer and the spring.
The spacer is only to get a good angle for the spring, and to distribute
the loads from the spring to the tail post over a larger area, so making
it thinner shouldn't hurt.

If you do go to the Scott tailwheel, you will likely find that it
doesn't fit the spring. You can grind the spring a bit, and there are
spacer blocks available to help with the fit. Have a look through the
archives of this list - I think someone described these a few months ago.
I think Scott make different size attachment fittings.

You can move your battery back to adjust the C of G - several here
have used a long, narrow battery (about 3 1/2" thick, by about 10 - 11"
long). These can be positioned on the right side of the fuselage, between
the bulkheads, leaving the floor open for sleeping. Just move it back until
you get the desired position....

The Murphy kick-out tailwheel works GREAT, once it is broken in. Be
sure to grease it regularly, especially the pin at the top. There should
be a grease fitting there for it, but it's not in the design, so you just
have to stuff a glob of grease into the underside with your finger, at
least once a month....

If you haven't already, you can save a LOT of weight up front by going
to the B & C lightweight starter, and a lightweight alternator, (over 30
lbs),
as well as the (now-almost-standard) 3 blade Warp Drive 72 inch prop with
17" of metal on the leading edge, and SQUARE tips !

Sounds like you're making good progress - keep at it. It's worth it !!

.....bobp

-----------------------------------orig.----------------------------------
At 09:04 PM 6/27/99 -0700, you wrote:

Bob, my Rebel had an aluminum tail spring which was even before the

composite

one. My serial # is 107R. With the newer replacement tail spring, an

additional

spacer TS-7 was added on top of the extra thickness of the new tail spring,
which is what lowered the strut attach bracket. I am not sure what purpose

it

served, so I removed it, leaving only the original TS-2 spacer in place.

That

gained back some altitude on the strut bracket, and now I have only 1/4

inch

negative dihedral. Do you think this is still a problem? I could replace

the

TS-2 with another spacer that is 1/8 inch less thick, and that would bring

me

back to the original stab height. I am using the Murphy tail wheel modified

to

kick out on a sharp turn. I hope it works. I am almost ready to do a weight

and

balance, so might still go for the heavier Scott tail wheel if I have a

problem.

I am using an O320.

Bob Patterson wrote:

Did you have a composite tail spring originally, Walter ?? If you are
using the standard Murphy tailwheel, you can shorten that spring and use
it with no problems. We have used one for 8 years - finally replaced it
last year, when it started to delaminate..... (After only 8 years outside
in the sun, and about 900 hours of landing on sometimes rough grass

strips,

and rougher asphalt ones ! ;-) )

We were able to trade the new metal spring for another composite

spring,

which was slightly thicker than the original, so just ground it down to

fit

the bracket.

Negative dihedral is definitely NOT a good idea - could effect

stability,

handling, and strength. You could remove or thin down the spacer above
the spring (assuming you have one ...) - this would be the easiest way.
I have seen folks use a thin piece of rubber instead of the upper

spacer -

cut from an inner tube, or a thin tire sidewall. Probably not a bad
idea - gives a little extra shock absorbing ....

The composite springs are probably not the best choice if you are
using a larger, heavier tailwheel, like the Scott 3200 or Maule (if you
can, choose the Scott - Maules tend to wear & shimmy MUCH sooner :-( ).
Scott makes a very nice, smaller tailwheel, the 2200, which is a good fit
for the Rebel, as well, but not as common as the 3200, and not much

cheaper,

either. Many builders who are using heavier engines (read O-320's) are
choosing the Scott 3200 because it adds at least 8 lb. right out on the
tail, which helps the C of G.


.....bobp

-----------------------------orig.---------------------------------------

--

At 12:49 PM 6/27/99 -0700, you wrote:

I have one of the earlier Rebels with the old thinner,
weaker tail springs, and upgraded to the latest stronger
tail spring along with the associated spacers, etc. I was
doing some final checks and adjustments of my controls, when
I noticed that the horizontal stabilizers had a slight
negative dihedral (about an inch). I then realized it was
due to the thicker tail spring and spacers which lowered my
tail skid attach bracket by about 5/16 of an inch. To get my
stabs level again, I need to redo my tail struts longer, or
put in a new tail skid attach bracket and space out the
strut attach holes slightly to fit the existing tail struts.

I am just wondering if anyone else has run into this, and
what their solution was. Does 1 or 2 inches of negative
dihedral in the tail make any difference? I plan to put the
plane on floats after a year or so, and can then go back to
the original tail spring set-up.

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Received: from bc.sympatico.ca (a3a23400.sympatico.bconnected.net
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for <murphy-rebel@dcsol.com>; Mon, 28 Jun 1999 19:17:10 -0700 (PDT)
Message-ID: <37782BDA.4D15162D@bc.sympatico.ca>
Date: Mon, 28 Jun 1999 19:13:47 -0700
From: Walter Klatt <Walter_Klatt@bc.sympatico.ca>
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To: " (Murphy Rebel Builders List)" <murphy-rebel@dcsol.com>
Subject: Re: New Aluminum tail spring
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Thanks Bob. It really helps to have "field" information. I sent a message to
MAM on
this issue, too, but haven't got a reply yet.

Using a thinner spacer would be the best solution, if it can handle the
load. I
don't understand why they added the additional spacer, TS-7, though, if not
for
added strength. I can see why the rubber would be a good idea for cushioning
the
impacts, but it would again lower the tail strut attach bracket which then
gives me
that undesirable negative dihedral.

I am using a lightweight Skytech starter and a Sprint alternator, along with
the
Warp Drive prop. Also, my firewall is cut back 3 inches. So I have taken
whatever
steps I know to reduce forward weight. However, I still have my battery
mounted on
the firewall, and I realize I may be dreaming, if I think that can remain. I
just
got my newly upholstered seats back, so am almost ready for that big C of G
test.

Thanks again for your help.

Bob Patterson wrote:

I had almost forgotten the earlier aluminum springs - we used one for a
season. It went flat after repeated bumps .... (aluminum is not a great
material for 'springs' :-) )

If you can use a thinner spacer, that would be great. As I mentioned,
some have added a thin piece of rubber between the spacer and the spring.
The spacer is only to get a good angle for the spring, and to distribute
the loads from the spring to the tail post over a larger area, so making
it thinner shouldn't hurt.

If you do go to the Scott tailwheel, you will likely find that it
doesn't fit the spring. You can grind the spring a bit, and there are
spacer blocks available to help with the fit. Have a look through the
archives of this list - I think someone described these a few months ago.
I think Scott make different size attachment fittings.

You can move your battery back to adjust the C of G - several here
have used a long, narrow battery (about 3 1/2" thick, by about 10 - 11"
long). These can be positioned on the right side of the fuselage, between
the bulkheads, leaving the floor open for sleeping. Just move it back

until

you get the desired position....

The Murphy kick-out tailwheel works GREAT, once it is broken in. Be
sure to grease it regularly, especially the pin at the top. There should
be a grease fitting there for it, but it's not in the design, so you just
have to stuff a glob of grease into the underside with your finger, at
least once a month....

If you haven't already, you can save a LOT of weight up front by going
to the B & C lightweight starter, and a lightweight alternator, (over 30

lbs),

as well as the (now-almost-standard) 3 blade Warp Drive 72 inch prop with
17" of metal on the leading edge, and SQUARE tips !

Sounds like you're making good progress - keep at it. It's worth it !!

.....bobp

-----------------------------------orig.----------------------------------
At 09:04 PM 6/27/99 -0700, you wrote:

Bob, my Rebel had an aluminum tail spring which was even before the

composite

one. My serial # is 107R. With the newer replacement tail spring, an

additional

spacer TS-7 was added on top of the extra thickness of the new tail

spring,

which is what lowered the strut attach bracket. I am not sure what

purpose it

served, so I removed it, leaving only the original TS-2 spacer in place.

That

gained back some altitude on the strut bracket, and now I have only 1/4

inch

negative dihedral. Do you think this is still a problem? I could replace

the

TS-2 with another spacer that is 1/8 inch less thick, and that would

bring me

back to the original stab height. I am using the Murphy tail wheel

modified to

kick out on a sharp turn. I hope it works. I am almost ready to do a

weight and

balance, so might still go for the heavier Scott tail wheel if I have a

problem.

I am using an O320.

Bob Patterson wrote:

Did you have a composite tail spring originally, Walter ?? If you are
using the standard Murphy tailwheel, you can shorten that spring and

use

it with no problems. We have used one for 8 years - finally replaced it
last year, when it started to delaminate..... (After only 8 years

outside

in the sun, and about 900 hours of landing on sometimes rough grass

strips,

and rougher asphalt ones ! ;-) )

We were able to trade the new metal spring for another composite

spring,

which was slightly thicker than the original, so just ground it down to

fit

the bracket.

Negative dihedral is definitely NOT a good idea - could effect

stability,

handling, and strength. You could remove or thin down the spacer above
the spring (assuming you have one ...) - this would be the easiest way.
I have seen folks use a thin piece of rubber instead of the upper

spacer -

cut from an inner tube, or a thin tire sidewall. Probably not a bad
idea - gives a little extra shock absorbing ....

The composite springs are probably not the best choice if you are
using a larger, heavier tailwheel, like the Scott 3200 or Maule (if you
can, choose the Scott - Maules tend to wear & shimmy MUCH sooner :-( ).
Scott makes a very nice, smaller tailwheel, the 2200, which is a good

fit

for the Rebel, as well, but not as common as the 3200, and not much

cheaper,

either. Many builders who are using heavier engines (read O-320's) are
choosing the Scott 3200 because it adds at least 8 lb. right out on the
tail, which helps the C of G.


.....bobp

-----------------------------orig.---------------------------------------

--

At 12:49 PM 6/27/99 -0700, you wrote: *----------------------------------------------------*
The Murphy Rebel Builders List is for the discussion
between builders and owners of Murphy Rebel aircraft.
Archives located at:
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*----------------------------------------------------*

*----------------------------------------------------*
The Murphy Rebel Builders List is for the discussion
between builders and owners of Murphy Rebel aircraft.
Archives located at:
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*----------------------------------------------------*

*----------------------------------------------------*
The Murphy Rebel Builders List is for the discussion
between builders and owners of Murphy Rebel aircraft.
Archives located at:
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*----------------------------------------------------*