Brake loads/Spring gear

[Doug Martin]

Alister; I am interested in the size of tires, type of tires,(smooth or
tread) and air pressure you are using? Also what are you using for brakes?
As I will be flying in the high deserts of the western U.S., and landing
on dirt roads and off airport on dry lake beds. It sounds like you are
doing the type of flying now that I will be doing in the furure with my
Elite.



At 01:55 PM 1/3/00 +1300, you wrote:

Hi all, Just though I would feed a little bit of information
regarding another area I am having a bit of trouble with on the Rebel.
As of late I have noticed once again a small amount movement around the
rivets on the doorpost below the doorsill level. On further inspection
distortion of the outer floor skin directly behind the 63 thou fingered
plate (SG-13) with some cracking of the paint around some of the rivets in
this area. This distortion is worse on the outer edges of the aircraft
around the Fus 35. but is still evident right across on a line with the
bulkhead just rear of the tips of the fingers on the SG-13. In
consultation with Murphy we are certain this is coming braking loads. I am
uncertain what is the primary cause i.e. the doorpost area or the area
behind the SG-13. But Murphy's suggested fix to me was a doubler covering
the lower doorpost area attached to the skins fore and aft of that and
increase the size of the rivets into the lower doorpost. I am sure that
will do the job, but being keen to make sure this doesn't repeat, I intend
to transfer the loads further back from the SG-13 by increasing the skin
thickness' in that area as well. I would like to qualify this damage a
bit. I am not at all sure that standard use of this aircraft would result
in this type of problem, a number of the areas I fly into are very rough
and quite short and the combination of braking loads (quite often with the
stick hard back but with the tail still in the air) and rough ground must
put on a lot of stress. " I also moved the seating back the same
distance, I have noticed that because of this the seat tracks that would
normally cover the bulkhead just rear of the SG13 and 14 and add some
shear strength to this area are now just behind that bulkhead perhaps
weakening it a little. Cheers Alister email:
yeoman@voyager.co.nz

Doug Martin
greyghost@powernet.net
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[Alister Yeoman]

Hi all,

Just though I would feed a little bit of information regarding another area I am having a bit of trouble with on the Rebel.

As of late I have noticed once again a small amount movement around the rivets on the doorpost below the doorsill level. On further inspection distortion of the outer floor skin directly behind the 63 thou fingered plate (SG-13) with some cracking of the paint around some of the rivets in this area. This distortion is worse on the outer edges of the aircraft around the Fus 35. but is still evident right across on a line with the bulkhead just rear of the tips of the fingers on the SG-13.

In consultation with Murphy we are certain this is coming braking loads. I am uncertain what is the primary cause i.e. the doorpost area or the area behind the SG-13. But Murphy's suggested fix to me was a doubler covering the lower doorpost area attached to the skins fore and aft of that and increase the size of the rivets into the lower doorpost.

I am sure that will do the job, but being keen to make sure this doesn't repeat, I intend to transfer the loads further back from the SG-13 by increasing the skin thickness' in that area as well.

I would like to qualify this damage a bit. I am not at all sure that standard use of this aircraft would result in this type of problem, a number of the areas I fly into are very rough and quite short and the combination of braking loads (quite often with the stick hard back but with the tail still in the air) and rough ground must put on a lot of stress.

Also another factor may be that with the firewall moved back 3" I also moved the seating back the same distance, I have noticed that because of this the seat tracks that would normally cover the bulkhead just rear of the SG13 and 14 and add some shear strength to this area are now just behind that bulkhead perhaps weakening it a little.

As with all information that comes thru' this forum, take out of this what you want. If you intend to use your aircraft the same way I do perhaps it may be worth some consideration.

Cheers

Alister

email: yeoman@voyager.co.n (yeoman@voyager.co.n)z

[Alister Yeoman]

Doug, I am running 8.50-6 tyres with smooth tread at about 15 lb pressure
any less shortens the takeoff run quite a bit). I have the latter brakes,
they are quite powerful, the limitation of brake use is quite often the
weight of the tail.

Alister

-----Original Message-----
From: Doug Martin <greyghost@powernet.net>
To: Murphy Rebel Builders List <murphy-rebel@dcsol.com>
Date: Monday, January 03, 2000 6:29 PM
Subject: Re: Brake loads/Spring gear

Alister; I am interested in the size of tires, type of tires,(smooth or
tread) and air pressure you are using? Also what are you using for brakes?
As I will be flying in the high deserts of the western U.S., and landing
on dirt roads and off airport on dry lake beds. It sounds like you are
doing the type of flying now that I will be doing in the furure with my
Elite.



At 01:55 PM 1/3/00 +1300, you wrote:

Hi all, Just though I would feed a little bit of information
regarding another area I am having a bit of trouble with on the Rebel.
As of late I have noticed once again a small amount movement around the
rivets on the doorpost below the doorsill level. On further inspection
distortion of the outer floor skin directly behind the 63 thou fingered
plate (SG-13) with some cracking of the paint around some of the rivets

in

this area. This distortion is worse on the outer edges of the aircraft
around the Fus 35. but is still evident right across on a line with the
bulkhead just rear of the tips of the fingers on the SG-13. In
consultation with Murphy we are certain this is coming braking loads. I

am

uncertain what is the primary cause i.e. the doorpost area or the area
behind the SG-13. But Murphy's suggested fix to me was a doubler covering
the lower doorpost area attached to the skins fore and aft of that and
increase the size of the rivets into the lower doorpost. I am sure that
will do the job, but being keen to make sure this doesn't repeat, I

intend

to transfer the loads further back from the SG-13 by increasing the skin
thickness' in that area as well. I would like to qualify this damage a
bit. I am not at all sure that standard use of this aircraft would result
in this type of problem, a number of the areas I fly into are very rough
and quite short and the combination of braking loads (quite often with

the

stick hard back but with the tail still in the air) and rough ground must
put on a lot of stress. " I also moved the seating back the same
distance, I have noticed that because of this the seat tracks that would
normally cover the bulkhead just rear of the SG13 and 14 and add some
shear strength to this area are now just behind that bulkhead perhaps
weakening it a little. Cheers Alister email:
yeoman@voyager.co.nz

Doug Martin
greyghost@powernet.net
*----------------------------------------------------*
The Murphy Rebel Builders List is for the discussion
between builders and owners of Murphy Rebel aircraft.
Archives located at:
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*----------------------------------------------------*

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between builders and owners of Murphy Rebel aircraft.
Archives located at:
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*----------------------------------------------------*




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[Dan Morehouse]

Hello Alister and company!

...On further inspection distortion of the outer floor skin directly behind the 63 thou fingered plate (SG-13) with some cracking of the paint around some of the rivets in this area. This distortion is worse on the outer edges of the aircraft around the Fus 35. but is still evident right across on a line with the bulkhead just rear of the tips of the fingers on the SG-13...
Between the end of my fingers of SG-13 and the bulkhead is about 2" or 2 rivets, the second connecting the floor with the bulkhead. Have you found stress fagigue along either one of these rivet lines, or is it in the last rivet of the fingers, or ...?

...I intend to transfer the loads further back from the SG-13 by increasing the skin thickness' in that area as well....

Do you mean transfer the loads from SG-13 back to the next bulkhead 2" away? .. or even further? If it's just to the nearest bulkhead one way for me to do it since I haven't riveted this area yet is to redo the SG-13 2" longer to tie into this bulkhead. Otherwise the thickness of SG-13 would make a doubler problematic, for me at least. How had you planned your doubler or otherwise 'increase the skin thickness' ?

But if you mean transfer the loads clear back to the next bulkhead, the double bulkheads, then maybe some more channels or stringers could be placed between the existing ones from the single bulkhead to the double one.

Also, I have already replace the Fus-35 angle with one that is roughly 2" x 2". Do you think this would be enough to avoid your problems? Or I could take the old Fus-35 and use it as a doubler on the inside of the corner wraps between the bulkheads if this is where it is needed most.

But Murphy's suggested fix to me was a doubler covering the lower doorpost area attached to the skins fore and aft of that and increase the size of the rivets into the lower doorpost.

Does this mean from the post to Fus-11 Side Panel, Fus -70 Corner Panel, and/or Fus-26 Lower Side Panel?

Let me know what you think and happy drilling!

Dan
R280

PS: Is the original message the most recent on this topic?

----- Original Message -----

From: Alister Yeoman (yeoman@voyager.co.nz)
To: Rebel (murphy-rebel@dcsol.com)
Sent: Sunday, January 02, 2000 4:55 PM
Subject: Brake loads/Spring gear


Hi all,

Just though I would feed a little bit of information regarding another area I am having a bit of trouble with on the Rebel.

As of late I have noticed once again a small amount movement around the rivets on the doorpost below the doorsill level. On further inspection distortion of the outer floor skin directly behind the 63 thou fingered plate (SG-13) with some cracking of the paint around some of the rivets in this area. This distortion is worse on the outer edges of the aircraft around the Fus 35. but is still evident right across on a line with the bulkhead just rear of the tips of the fingers on the SG-13.

In consultation with Murphy we are certain this is coming braking loads. I am uncertain what is the primary cause i.e. the doorpost area or the area behind the SG-13. But Murphy's suggested fix to me was a doubler covering the lower doorpost area attached to the skins fore and aft of that and increase the size of the rivets into the lower doorpost.

I am sure that will do the job, but being keen to make sure this doesn't repeat, I intend to transfer the loads further back from the SG-13 by increasing the skin thickness' in that area as well.

I would like to qualify this damage a bit. I am not at all sure that standard use of this aircraft would result in this type of problem, a number of the areas I fly into are very rough and quite short and the combination of braking loads (quite often with the stick hard back but with the tail still in the air) and rough ground must put on a lot of stress.

Also another factor may be that with the firewall moved back 3" I also moved the seating back the same distance, I have noticed that because of this the seat tracks that would normally cover the bulkhead just rear of the SG13 and 14 and add some shear strength to this area are now just behind that bulkhead perhaps weakening it a little.

As with all information that comes thru' this forum, take out of this what you want. If you intend to use your aircraft the same way I do perhaps it may be worth some consideration.

Cheers

Alister

email: yeoman@voyager.co.n (yeoman@voyager.co.n)z

[Dan Morehouse]

Oooh! I think I'll wait to install my SG-13, in that case.

Thanks for the feedback, Alister. Look forward to hearing what you come up with.

Take care,
Dan
R280

----- Original Message -----
From: Alister Yeoman (yeoman@voyager.co.nz)
To: Murphy Rebel Builders List (murphy-rebel@dcsol.com)
Sent: Tuesday, February 01, 2000 1:29 PM
Subject: Re: Brake loads/Spring gear



Hi Dan,
Sorry about the delay I got a little tied up for a few days. Yes the last message was the first.

Thats right, about 2" back from the end of the fingers along the rivet line connecting to the floor bulkhead there is fatigue and working rivets.

I intend to run the 63 thou SG-13 well back to probably the double bulkhead further back. The reason being if the brakes are applied and you get someone to push backwards and forwards on the prop simulating braking loads the lower floor skin 'pants' quite badly. The floor skin probably does not need to be this heavy but remember I want to repair this without pulling the carrythough apart so I am limited in the way I can approach the problem.

I am not entirely happy with the doubler on the side panel fix, as you are asking the doorpost to accept the majority of the load of the braking, this is putting a lot of stress on the wing strut attach brackets ( remember these join the bottom carrythrough to the doorpost). Once again when you apply the brakes and push backwards and forwards on the aircraft it is possible to feel the strut attach bracket flexing, over time this could ( will?) lead to cracks forming.(not a good place to get them!)

All I can say at this time is that I am still working on the problem, I have the plane out of the air now and will progressively add strength to the area until I am satisfied. The end mod may end a little radical!! I will keep you posted.

Cheers

Alister

-----Original Message-----
From: Dan Morehouse <DanMorehouse@home.com (DanMorehouse@home.com)>
To: Murphy Rebel Builders List <murphy-rebel@dcsol.com (murphy-rebel@dcsol.com)>
Date: Sunday, January 30, 2000 12:02 PM
Subject: Re: Brake loads/Spring gear


Hello Alister and company!

...On further inspection distortion of the outer floor skin directly behind the 63 thou fingered plate (SG-13) with some cracking of the paint around some of the rivets in this area. This distortion is worse on the outer edges of the aircraft around the Fus 35. but is still evident right across on a line with the bulkhead just rear of the tips of the fingers on the SG-13...
Between the end of my fingers of SG-13 and the bulkhead is about 2" or 2 rivets, the second connecting the floor with the bulkhead. Have you found stress fagigue along either one of these rivet lines, or is it in the last rivet of the fingers, or ...?

...I intend to transfer the loads further back from the SG-13 by increasing the skin thickness' in that area as well....

Do you mean transfer the loads from SG-13 back to the next bulkhead 2" away? .. or even further? If it's just to the nearest bulkhead one way for me to do it since I haven't riveted this area yet is to redo the SG-13 2" longer to tie into this bulkhead. Otherwise the thickness of SG-13 would make a doubler problematic, for me at least. How had you planned your doubler or otherwise 'increase the skin thickness' ?

But if you mean transfer the loads clear back to the next bulkhead, the double bulkheads, then maybe some more channels or stringers could be placed between the existing ones from the single bulkhead to the double one.

Also, I have already replace the Fus-35 angle with one that is roughly 2" x 2". Do you think this would be enough to avoid your problems? Or I could take the old Fus-35 and use it as a doubler on the inside of the corner wraps between the bulkheads if this is where it is needed most.

But Murphy's suggested fix to me was a doubler covering the lower doorpost area attached to the skins fore and aft of that and increase the size of the rivets into the lower doorpost.

Does this mean from the post to Fus-11 Side Panel, Fus -70 Corner Panel, and/or Fus-26 Lower Side Panel?

Let me know what you think and happy drilling!

Dan
R280

PS: Is the original message the most recent on this topic?

----- Original Message -----

From: Alister Yeoman (yeoman@voyager.co.nz)
To: Rebel (murphy-rebel@dcsol.com)
Sent: Sunday, January 02, 2000 4:55 PM
Subject: Brake loads/Spring gear


Hi all,

Just though I would feed a little bit of information regarding another area I am having a bit of trouble with on the Rebel.

As of late I have noticed once again a small amount movement around the rivets on the doorpost below the doorsill level. On further inspection distortion of the outer floor skin directly behind the 63 thou fingered plate (SG-13) with some cracking of the paint around some of the rivets in this area. This distortion is worse on the outer edges of the aircraft around the Fus 35. but is still evident right across on a line with the bulkhead just rear of the tips of the fingers on the SG-13.

In consultation with Murphy we are certain this is coming braking loads. I am uncertain what is the primary cause i.e. the doorpost area or the area behind the SG-13. But Murphy's suggested fix to me was a doubler covering the lower doorpost area attached to the skins fore and aft of that and increase the size of the rivets into the lower doorpost.

I am sure that will do the job, but being keen to make sure this doesn't repeat, I intend to transfer the loads further back from the SG-13 by increasing the skin thickness' in that area as well.

I would like to qualify this damage a bit. I am not at all sure that standard use of this aircraft would result in this type of problem, a number of the areas I fly into are very rough and quite short and the combination of braking loads (quite often with the stick hard back but with the tail still in the air) and rough ground must put on a lot of stress.

Also another factor may be that with the firewall moved back 3" I also moved the seating back the same distance, I have noticed that because of this the seat tracks that would normally cover the bulkhead just rear of the SG13 and 14 and add some shear strength to this area are now just behind that bulkhead perhaps weakening it a little.

As with all information that comes thru' this forum, take out of this what you want. If you intend to use your aircraft the same way I do perhaps it may be worth some consideration.

Cheers

Alister

email: yeoman@voyager.co.n (yeoman@voyager.co.n)z

[Richard DeCiero]

Hello,
I have also been concerned about how the torque of the spring gear will want to crank on the carrythru tubes. One alternative to help spread this load would be to run a piece of angle from the two outboard bolts back toward the rear to the two fuse bulkheads. That piece would be about 26" long and could also be tied into the rear bungee gear brackets. I installed the rear bungee gear brackets just in case this spring gear didn't work out. At this point I wish I had just went with the bungee gear as Bob P. has been saying all along. We all thought that the spring gear would be easier to install etc. but with all of the comments regarding the problems I'm not sure it is worth the trouble. Wayne O'Shay has a nice durable, functional looking and reasonably priced gear retrofit for the bungee gear setup. I wonder how many gear problems Alister would have if he was using a bungee gear setup?
All please comment on all of the above.
Thanks bye for now,
Rick D.
Rebel S/N 446
P.S. Wayne, Thanks for the Phone for the Crown silicone. I knew someone would ask that question as I had gone thru the same search process. One place in California,USA sold a silicone spray for sewing machines. The product description said that it contained "no chlorinated solvents" perhaps this is the key to perserving the delrin.
Dan Morehouse wrote:

Oooh! I think I'll wait to install my SG-13, in that case. Thanks for the feedback, Alister. Look forward to hearing what you come up with. Take care,DanR280

----- Original Message -----
From: Alister Yeoman (yeoman@voyager.co.nz)
To: Murphy Rebel Builders List (murphy-rebel@dcsol.com)
Sent: Tuesday, February 01, 2000 1:29 PM
Subject: Re: Brake loads/Spring gear
Hi Dan, Sorry about the delay I got a little tied up for a few days. Yes the last message was the first. Thats right, about 2" back from the end of the fingers along the rivet line connecting to the floor bulkhead there is fatigue and working rivets. I intend to run the 63 thou SG-13 well back to probably the double bulkhead further back. The reason being if the brakes are applied and you get someone to push backwards and forwards on the prop simulating braking loads the lower floor skin 'pants' quite badly. The floor skin probably does not need to be this heavy but remember I want to repair this without pulling the carrythough apart so I am limited in the way I can approach the problem. I am not entirely happy with the doubler on the side panel fix, as you are asking the doorpost to accept the majority of the load of the braking, this is putting a lot of stress on the wing strut attach brackets ( remember these join the bottom carrythrough to the doorpost). Once again when you apply the brakes and push backwards and forwards on the aircraft it is possible to feel the strut attach bracket flexing, over time this could ( will?) lead to cracks forming.(not a good place to get them!) All I can say at this time is that I am still working on the problem, I have the plane out of the air now and will progressively add strength to the area until I am satisfied. The end mod may end a little radical!! I will keep you posted. Cheers Alister

-----Original Message-----
From: Dan Morehouse <DanMorehouse@home.com (DanMorehouse@home.com)>
To: Murphy Rebel Builders List <murphy-rebel@dcsol.com (murphy-rebel@dcsol.com)>
Date: Sunday, January 30, 2000 12:02 PM
Subject: Re: Brake loads/Spring gear
Hello Alister and company! ...On further inspection distortion of the outer floor skin directly behind the 63 thou fingered plate (SG-13) with some cracking of the paint around some of the rivets in this area. This distortion is worse on the outer edges of the aircraft around the Fus 35. but is still evident right across on a line with the bulkhead just rear of the tips of the fingers on the SG-13... Between the end of my fingers of SG-13 and the bulkhead is about 2" or 2 rivets, the second connecting the floor with the bulkhead. Have you found stress fagigue along either one of these rivet lines, or is it in the last rivet of the fingers, or ...? ...I intend to transfer the loads further back from the SG-13 by increasing the skin thickness' in that area as well.... Do you mean transfer the loads from SG-13 back to the next bulkhead 2" away? .. or even further? If it's just to the nearest bulkhead one way for me to do it since I haven't riveted this area yet is to redo the SG-13 2" longer to tie into this bulkhead. Otherwise the thickness of SG-13 would make a doubler problematic, for me at least. How had you planned your doubler or otherwise 'increase the skin thickness' ? But if you mean transfer the loads clear back to the next bulkhead, the double bulkheads, then maybe some more channels or stringers could be placed between the existing ones from the single bulkhead to the double one. Also, I have already replace the Fus-35 angle with one that is roughly 2" x 2". Do you think this would be enough to avoid your problems? Or I could take the old Fus-35 and use it as a doubler on the inside of the corner wraps between the bulkheads if this is where it is needed most. But Murphy's suggested fix to me was a doubler covering the lower doorpost area attached to the skins fore and aft of that and increase the size of the rivets into the lower doorpost. Does this mean from the post to Fus-11 Side Panel, Fus -70 Corner Panel, and/or Fus-26 Lower Side Panel? Let me know what you think and happy drilling! DanR280 PS: Is the original message the most recent on this topic? ----- Original Message -----

[Wayne G. O'Shea]

Anyone that is installing the spring gear and planning to fly on SKIS should install the "bungee gear" rear drag brace attach brackets (or at least one of each set), so you have a place to hook your check cable to for the back of the ski! Otherwise you will have to run a cable all the way back to the float point fitting, or up to the gear leg. (which makes a real nice "trip line" when you climb out!)

Blue skies,
Wayne G. O'Shea
www.irishfield.on.ca

-----Original Message-----
From: Richard DeCiero <rsdec1@star.net (rsdec1@star.net)>
To: (Murphy Rebel Builders List) <murphy-rebel@dcsol.com (murphy-rebel@dcsol.com)>
Date: Wednesday, February 02, 2000 5:25 PM
Subject: Re: Brake loads/Spring gear


I installed the rear bungee gear brackets just in case this spring gear didn't work out.

[Brian Cross]

-----Original Message-----
From: Richard DeCiero [mailto:rsdec1@star.net]
Sent: Wednesday, February 02, 2000 5:38 PM
To: (Murphy Rebel Builders List)
Subject: Re: Brake loads/Spring gear


Hello,
I have also been concerned about how the torque of the spring gear will want to crank on the carrythru tubes. One alternative to help spread this load would be to run a piece of angle from the two outboard bolts back toward the rear to the two fuse bulkheads. That piece would be about 26" long and could also be tied into the rear bungee gear brackets. I installed the rear bungee gear brackets just in case this spring gear didn't work out. At this point I wish I had just went with the bungee gear as Bob P. has been saying all along. We all thought that the spring gear would be easier to install etc. but with all of the comments regarding the problems I'm not sure it is worth the trouble. Wayne O'Shay has a nice durable, functional looking and reasonably priced gear retrofit for the bungee gear setup. I wonder how many gear problems Alister would have if he was using a bungee gear setup?
All please comment on all of the above.
Thanks bye for now,
Rick D.
Rebel S/N 446
P.S. Wayne, Thanks for the Phone for the Crown silicone. I knew someone would ask that question as I had gone thru the same search process. One place in California,USA sold a silicone spray for sewing machines. The product description said that it contained "no chlorinated solvents" perhaps this is the key to perserving the delrin.
Dan Morehouse wrote:

Oooh! I think I'll wait to install my SG-13, in that case. Thanks for the feedback, Alister. Look forward to hearing what you come up with. Take care,DanR280

----- Original Message -----
From: Alister Yeoman (yeoman@voyager.co.nz)
To: Murphy Rebel Builders List (murphy-rebel@dcsol.com)
Sent: Tuesday, February 01, 2000 1:29 PM
Subject: Re: Brake loads/Spring gear
Hi Dan, Sorry about the delay I got a little tied up for a few days. Yes the last message was the first. Thats right, about 2" back from the end of the fingers along the rivet line connecting to the floor bulkhead there is fatigue and working rivets. I intend to run the 63 thou SG-13 well back to probably the double bulkhead further back. The reason being if the brakes are applied and you get someone to push backwards and forwards on the prop simulating braking loads the lower floor skin 'pants' quite badly. The floor skin probably does not need to be this heavy but remember I want to repair this without pulling the carrythough apart so I am limited in the way I can approach the problem. I am not entirely happy with the doubler on the side panel fix, as you are asking the doorpost to accept the majority of the load of the braking, this is putting a lot of stress on the wing strut attach brackets ( remember these join the bottom carrythrough to the doorpost). Once again when you apply the brakes and push backwards and forwards on the aircraft it is possible to feel the strut attach bracket flexing, over time this could ( will?) lead to cracks forming.(not a good place to get them!) All I can say at this time is that I am still working on the problem, I have the plane out of the air now and will progressively add strength to the area until I am satisfied. The end mod may end a little radical!! I will keep you posted. Cheers Alister

[Brian Cross]

Hello There

I have built both types of gears - spring & bungee. The bungee gear certainly is alot easier to build. No contest here.

On the other hand, I am sure, by Alister's own accounts of some of the hairy places he flies into, he puts loads on his landing gear

that few of the rest of us would ever experience. By this I mean, that this is not a fair comparison of the spring vs. the bungee

system.


Alister, we are all jealous of some of the terrain & beauty which you certainly must enjoy in your country. This has been brought to

light again even tonight as I was again watching the America's Cup sailing which is taking place in Auckland right now. ( America

One just tied up the series with Prada (Italy) 3-3 in a best out of nine contest). Such a beautiful country there.


Best Regards


Brian #328R


[Brian Cross]

---Original Message-----
From: Richard DeCiero [mailto:rsdec1@star.net]
Sent: Wednesday, February 02, 2000 5:38 PM
To: (Murphy Rebel Builders List)
Subject: Re: Brake loads/Spring gear

Hello,
I have also been concerned about how the torque of the spring gear will want to crank on the carrythru tubes. One alternative to help spread this load would be to run a piece of angle from the two outboard bolts back toward the rear to the two fuse bulkheads. That piece would be about 26" long and could also be tied into the rear bungee gear brackets. I installed the rear bungee gear brackets just in case this spring gear didn't work out. At this point I wish I had just went with the bungee gear as Bob P. has been saying all along. We all thought that the spring gear would be easier to install etc. but with all of the comments regarding the problems I'm not sure it is worth the trouble. Wayne O'Shay has a nice durable, functional looking and reasonably priced gear retrofit for the bungee gear setup. I wonder how many gear problems Alister would have if he was using a bungee gear setup?
All please comment on all of the above.
Thanks bye for now,
Rick D.
Rebel S/N 446
P.S. Wayne, Thanks for the Phone for the Crown silicone. I knew someone would ask that question as I had gone thru the same search process. One place in California,USA sold a silicone spray for sewing machines. The product description said that it contained "no chlorinated solvents" perhaps this is the key to perserving the delrin.
Dan Morehouse wrote:

Oooh! I think I'll wait to install my SG-13, in that case. Thanks for the feedback, Alister. Look forward to hearing what you come up with. Take care,DanR280

----- Original Message -----
From: Alister Yeoman (yeoman@voyager.co.nz)
To: Murphy Rebel Builders List (murphy-rebel@dcsol.com)
Sent: Tuesday, February 01, 2000 1:29 PM
Subject: Re: Brake loads/Spring gear
Hi Dan, Sorry about the delay I got a little tied up for a few days. Yes the last message was the first. Thats right, about 2" back from the end of the fingers along the rivet line connecting to the floor bulkhead there is fatigue and working rivets. I intend to run the 63 thou SG-13 well back to probably the double bulkhead further back. The reason being if the brakes are applied and you get someone to push backwards and forwards on the prop simulating braking loads the lower floor skin 'pants' quite badly. The floor skin probably does not need to be this heavy but remember I want to repair this without pulling the carrythough apart so I am limited in the way I can approach the problem. I am not entirely happy with the doubler on the side panel fix, as you are asking the doorpost to accept the majority of the load of the braking, this is putting a lot of stress on the wing strut attach brackets ( remember these join the bottom carrythrough to the doorpost). Once again when you apply the brakes and push backwards and forwards on the aircraft it is possible to feel the strut attach bracket flexing, over time this could ( will?) lead to cracks forming.(not a good place to get them!) All I can say at this time is that I am still working on the problem, I have the plane out of the air now and will progressively add strength to the area until I am satisfied. The end mod may end a little radical!! I will keep you posted. Cheers Alister

[Alister Yeoman]

Hi Dan,
Sorry about the delay I got a little tied up for a few days. Yes the last message was the first.

Thats right, about 2" back from the end of the fingers along the rivet line connecting to the floor bulkhead there is fatigue and working rivets.

I intend to run the 63 thou SG-13 well back to probably the double bulkhead further back. The reason being if the brakes are applied and you get someone to push backwards and forwards on the prop simulating braking loads the lower floor skin 'pants' quite badly. The floor skin probably does not need to be this heavy but remember I want to repair this without pulling the carrythough apart so I am limited in the way I can approach the problem.

I am not entirely happy with the doubler on the side panel fix, as you are asking the doorpost to accept the majority of the load of the braking, this is putting a lot of stress on the wing strut attach brackets ( remember these join the bottom carrythrough to the doorpost). Once again when you apply the brakes and push backwards and forwards on the aircraft it is possible to feel the strut attach bracket flexing, over time this could ( will?) lead to cracks forming.(not a good place to get them!)

All I can say at this time is that I am still working on the problem, I have the plane out of the air now and will progressively add strength to the area until I am satisfied. The end mod may end a little radical!! I will keep you posted.

Cheers

Alister

-----Original Message-----
From: Dan Morehouse <DanMorehouse@home.com (DanMorehouse@home.com)>
To: Murphy Rebel Builders List <murphy-rebel@dcsol.com (murphy-rebel@dcsol.com)>
Date: Sunday, January 30, 2000 12:02 PM
Subject: Re: Brake loads/Spring gear


Hello Alister and company!

...On further inspection distortion of the outer floor skin directly behind the 63 thou fingered plate (SG-13) with some cracking of the paint around some of the rivets in this area. This distortion is worse on the outer edges of the aircraft around the Fus 35. but is still evident right across on a line with the bulkhead just rear of the tips of the fingers on the SG-13...
Between the end of my fingers of SG-13 and the bulkhead is about 2" or 2 rivets, the second connecting the floor with the bulkhead. Have you found stress fagigue along either one of these rivet lines, or is it in the last rivet of the fingers, or ...?

...I intend to transfer the loads further back from the SG-13 by increasing the skin thickness' in that area as well....

Do you mean transfer the loads from SG-13 back to the next bulkhead 2" away? .. or even further? If it's just to the nearest bulkhead one way for me to do it since I haven't riveted this area yet is to redo the SG-13 2" longer to tie into this bulkhead. Otherwise the thickness of SG-13 would make a doubler problematic, for me at least. How had you planned your doubler or otherwise 'increase the skin thickness' ?

But if you mean transfer the loads clear back to the next bulkhead, the double bulkheads, then maybe some more channels or stringers could be placed between the existing ones from the single bulkhead to the double one.

Also, I have already replace the Fus-35 angle with one that is roughly 2" x 2". Do you think this would be enough to avoid your problems? Or I could take the old Fus-35 and use it as a doubler on the inside of the corner wraps between the bulkheads if this is where it is needed most.

But Murphy's suggested fix to me was a doubler covering the lower doorpost area attached to the skins fore and aft of that and increase the size of the rivets into the lower doorpost.

Does this mean from the post to Fus-11 Side Panel, Fus -70 Corner Panel, and/or Fus-26 Lower Side Panel?

Let me know what you think and happy drilling!

Dan
R280

PS: Is the original message the most recent on this topic?

----- Original Message -----

From: Alister Yeoman (yeoman@voyager.co.nz)
To: Rebel (murphy-rebel@dcsol.com)
Sent: Sunday, January 02, 2000 4:55 PM
Subject: Brake loads/Spring gear


Hi all,

Just though I would feed a little bit of information regarding another area I am having a bit of trouble with on the Rebel.

As of late I have noticed once again a small amount movement around the rivets on the doorpost below the doorsill level. On further inspection distortion of the outer floor skin directly behind the 63 thou fingered plate (SG-13) with some cracking of the paint around some of the rivets in this area. This distortion is worse on the outer edges of the aircraft around the Fus 35. but is still evident right across on a line with the bulkhead just rear of the tips of the fingers on the SG-13.

In consultation with Murphy we are certain this is coming braking loads. I am uncertain what is the primary cause i.e. the doorpost area or the area behind the SG-13. But Murphy's suggested fix to me was a doubler covering the lower doorpost area attached to the skins fore and aft of that and increase the size of the rivets into the lower doorpost.

I am sure that will do the job, but being keen to make sure this doesn't repeat, I intend to transfer the loads further back from the SG-13 by increasing the skin thickness' in that area as well.

I would like to qualify this damage a bit. I am not at all sure that standard use of this aircraft would result in this type of problem, a number of the areas I fly into are very rough and quite short and the combination of braking loads (quite often with the stick hard back but with the tail still in the air) and rough ground must put on a lot of stress.

Also another factor may be that with the firewall moved back 3" I also moved the seating back the same distance, I have noticed that because of this the seat tracks that would normally cover the bulkhead just rear of the SG13 and 14 and add some shear strength to this area are now just behind that bulkhead perhaps weakening it a little.

As with all information that comes thru' this forum, take out of this what you want. If you intend to use your aircraft the same way I do perhaps it may be worth some consideration.

Cheers

Alister

email: yeoman@voyager.co.n (yeoman@voyager.co.n)z

[Brian Cross]

HI Alister

I could not even hazard a guess, but, I hope that the America's Cup stays in New Zealand so that we can see more broadcasts from your native land. It would be a good excuse for my wife & I to travel to NZ for the next cup sailoff in 2002 or so.

Happy flying

Brian #328R

-----Original Message-----
From: Alister Yeoman [mailto:yeoman@voyager.co.nz]
Sent: Thursday, February 03, 2000 1:30 AM
To: Murphy Rebel Builders List
Subject: Re: Brake loads/Spring gear


OK Brian, who are you putting your money on? is America One going to bring home the bacon?

Alister

-----Original Message-----
From: Brian Cross <rebelair@idirect.com (rebelair@idirect.com)>
To: Murphy Rebel Builders List <murphy-rebel@dcsol.com (murphy-rebel@dcsol.com)>
Date: Thursday, February 03, 2000 6:35 PM
Subject: RE: Brake loads/Spring gear


Hello There

I have built both types of gears - spring & bungee. The bungee gear certainly is alot easier to build. No contest here.

On the other hand, I am sure, by Alister's own accounts of some of the hairy places he flies into, he puts loads on his landing gear

that few of the rest of us would ever experience. By this I mean, that this is not a fair comparison of the spring vs. the bungee

system.


Alister, we are all jealous of some of the terrain & beauty which you certainly must enjoy in your country. This has been brought to

light again even tonight as I was again watching the America's Cup sailing which is taking place in Auckland right now. ( America

One just tied up the series with Prada (Italy) 3-3 in a best out of nine contest). Such a beautiful country there.


Best Regards


Brian #328R


[Brian Cross]

---Original Message-----
From: Richard DeCiero [mailto:rsdec1@star.net]
Sent: Wednesday, February 02, 2000 5:38 PM
To: (Murphy Rebel Builders List)
Subject: Re: Brake loads/Spring gear

Hello,
I have also been concerned about how the torque of the spring gear will want to crank on the carrythru tubes. One alternative to help spread this load would be to run a piece of angle from the two outboard bolts back toward the rear to the two fuse bulkheads. That piece would be about 26" long and could also be tied into the rear bungee gear brackets. I installed the rear bungee gear brackets just in case this spring gear didn't work out. At this point I wish I had just went with the bungee gear as Bob P. has been saying all along. We all thought that the spring gear would be easier to install etc. but with all of the comments regarding the problems I'm not sure it is worth the trouble. Wayne O'Shay has a nice durable, functional looking and reasonably priced gear retrofit for the bungee gear setup. I wonder how many gear problems Alister would have if he was using a bungee gear setup?
All please comment on all of the above.
Thanks bye for now,
Rick D.
Rebel S/N 446
P.S. Wayne, Thanks for the Phone for the Crown silicone. I knew someone would ask that question as I had gone thru the same search process. One place in California,USA sold a silicone spray for sewing machines. The product description said that it contained "no chlorinated solvents" perhaps this is the key to perserving the delrin.
Dan Morehouse wrote:

[Alister Yeoman]

Hi Rick,
You have actually hit the nail right on the head, the radical fix I was talking about is along those lines.

I am considering putting a 2" to about 2-1/2 " deep i beam from the heads of the straddle bracket ( fitting longer bolts ) back to the station where the rear bungee gear attach point is. The deeper i beam will give additional leverage. I dont have have the rear attach brackets so I am fitting two 1/4" nut plates on either side at that point. There would be a lot of tortional loads just rear of the straddle bracket and I am not sure if a peice of angle would be strong enough, a well designed i beam should do it though, it could also tapper back to the rear.

Yes, it is an interesting question if I would be having any problems if I had the bungee gear. I really can't comment because mine is the only Rebel flying in NZ so I have nothing to compare it with.

Cheers

Alister

-----Original Message-----
From: Richard DeCiero <rsdec1@star.net (rsdec1@star.net)>
To: (Murphy Rebel Builders List) <murphy-rebel@dcsol.com (murphy-rebel@dcsol.com)>
Date: Thursday, February 03, 2000 11:25 AM
Subject: Re: Brake loads/Spring gear


Hello,
I have also been concerned about how the torque of the spring gear will want to crank on the carrythru tubes. One alternative to help spread this load would be to run a piece of angle from the two outboard bolts back toward the rear to the two fuse bulkheads. That piece would be about 26" long and could also be tied into the rear bungee gear brackets. I installed the rear bungee gear brackets just in case this spring gear didn't work out. At this point I wish I had just went with the bungee gear as Bob P. has been saying all along. We all thought that the spring gear would be easier to install etc. but with all of the comments regarding the problems I'm not sure it is worth the trouble. Wayne O'Shay has a nice durable, functional looking and reasonably priced gear retrofit for the bungee gear setup. I wonder how many gear problems Alister would have if he was using a bungee gear setup?
All please comment on all of the above.
Thanks bye for now,
Rick D.
Rebel S/N 446
P.S. Wayne, Thanks for the Phone for the Crown silicone. I knew someone would ask that question as I had gone thru the same search process. One place in California,USA sold a silicone spray for sewing machines. The product description said that it contained "no chlorinated solvents" perhaps this is the key to perserving the delrin.
Dan Morehouse wrote:

Oooh! I think I'll wait to install my SG-13, in that case. Thanks for the feedback, Alister. Look forward to hearing what you come up with. Take care,DanR280

----- Original Message -----
From: Alister Yeoman (yeoman@voyager.co.nz)
To: Murphy Rebel Builders List (murphy-rebel@dcsol.com)
Sent: Tuesday, February 01, 2000 1:29 PM
Subject: Re: Brake loads/Spring gear
Hi Dan, Sorry about the delay I got a little tied up for a few days. Yes the last message was the first. Thats right, about 2" back from the end of the fingers along the rivet line connecting to the floor bulkhead there is fatigue and working rivets. I intend to run the 63 thou SG-13 well back to probably the double bulkhead further back. The reason being if the brakes are applied and you get someone to push backwards and forwards on the prop simulating braking loads the lower floor skin 'pants' quite badly. The floor skin probably does not need to be this heavy but remember I want to repair this without pulling the carrythough apart so I am limited in the way I can approach the problem. I am not entirely happy with the doubler on the side panel fix, as you are asking the doorpost to accept the majority of the load of the braking, this is putting a lot of stress on the wing strut attach brackets ( remember these join the bottom carrythrough to the doorpost). Once again when you apply the brakes and push backwards and forwards on the aircraft it is possible to feel the strut attach bracket flexing, over time this could ( will?) lead to cracks forming.(not a good place to get them!) All I can say at this time is that I am still working on the problem, I have the plane out of the air now and will progressively add strength to the area until I am satisfied. The end mod may end a little radical!! I will keep you posted. Cheers Alister

[Alister Yeoman]

OK Brian, who are you putting your money on? is America One going to bring home the bacon?

Alister

-----Original Message-----
From: Brian Cross <rebelair@idirect.com (rebelair@idirect.com)>
To: Murphy Rebel Builders List <murphy-rebel@dcsol.com (murphy-rebel@dcsol.com)>
Date: Thursday, February 03, 2000 6:35 PM
Subject: RE: Brake loads/Spring gear


Hello There

I have built both types of gears - spring & bungee. The bungee gear certainly is alot easier to build. No contest here.

On the other hand, I am sure, by Alister's own accounts of some of the hairy places he flies into, he puts loads on his landing gear

that few of the rest of us would ever experience. By this I mean, that this is not a fair comparison of the spring vs. the bungee

system.


Alister, we are all jealous of some of the terrain & beauty which you certainly must enjoy in your country. This has been brought to

light again even tonight as I was again watching the America's Cup sailing which is taking place in Auckland right now. ( America

One just tied up the series with Prada (Italy) 3-3 in a best out of nine contest). Such a beautiful country there.


Best Regards


Brian #328R


[Brian Cross]

---Original Message-----
From: Richard DeCiero [mailto:rsdec1@star.net]
Sent: Wednesday, February 02, 2000 5:38 PM
To: (Murphy Rebel Builders List)
Subject: Re: Brake loads/Spring gear

Hello,
I have also been concerned about how the torque of the spring gear will want to crank on the carrythru tubes. One alternative to help spread this load would be to run a piece of angle from the two outboard bolts back toward the rear to the two fuse bulkheads. That piece would be about 26" long and could also be tied into the rear bungee gear brackets. I installed the rear bungee gear brackets just in case this spring gear didn't work out. At this point I wish I had just went with the bungee gear as Bob P. has been saying all along. We all thought that the spring gear would be easier to install etc. but with all of the comments regarding the problems I'm not sure it is worth the trouble. Wayne O'Shay has a nice durable, functional looking and reasonably priced gear retrofit for the bungee gear setup. I wonder how many gear problems Alister would have if he was using a bungee gear setup?
All please comment on all of the above.
Thanks bye for now,
Rick D.
Rebel S/N 446
P.S. Wayne, Thanks for the Phone for the Crown silicone. I knew someone would ask that question as I had gone thru the same search process. One place in California,USA sold a silicone spray for sewing machines. The product description said that it contained "no chlorinated solvents" perhaps this is the key to perserving the delrin.
Dan Morehouse wrote:

Oooh! I think I'll wait to install my SG-13, in that case. Thanks for the feedback, Alister. Look forward to hearing what you come up with. Take care,DanR280

[AzAlexR]

Hi Alistrer,
I know you wrote this to Brian, but Iwanted you to know my wife & I spent a
mo. in NZ Oct. '99 and words and people can't describe what a great time we
had. We can talk about that later.
I am about to start a SR-2500 and have known MAM since the intro of that
plane in Arlington, '95. Lots of good info on the foeum but more important
is the people I've met. In SYD is my friend, Rick Harper who is building a
Rebel. In Wellington, my friend Tony Chatfield who is restoring Buicks (
which I do also).

Had a great time at the docks i Auckland and all of N. NZ to Cape Rangie(sp)
and the towns south. Then the south is. Next time I hope to visit with you.
I will be back.

Regards,
Alex Russell
*----------------------------------------------------*
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between builders and owners of Murphy Rebel aircraft.
Archives located at:
http://www.dcsol.com/murphy-rebel/lists/default.htm
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[Brian Cross]

Hi Alister & Alex

Bit of a shock about America One get knocked out by Prada after being down 3
to 1 and then winning 3 straight. I am sure they didn't know what hit them.

I will really be rooting for the Kiwis on the 19th.

Best Regards


Brian #328R

-----Original Message-----
From: AzAlexR@aol.com [mailto:AzAlexR@aol.com]
Sent: Monday, February 07, 2000 8:38 PM
To: murphy-rebel@dcsol.com
Subject: Re: Brake loads/Spring gear


Hi Alistrer,
I know you wrote this to Brian, but Iwanted you to know my wife & I spent a
mo. in NZ Oct. '99 and words and people can't describe what a great time we
had. We can talk about that later.
I am about to start a SR-2500 and have known MAM since the intro of that
plane in Arlington, '95. Lots of good info on the foeum but more important
is the people I've met. In SYD is my friend, Rick Harper who is building a
Rebel. In Wellington, my friend Tony Chatfield who is restoring Buicks

which I do also).

Had a great time at the docks i Auckland and all of N. NZ to Cape Rangie(sp)
and the towns south. Then the south is. Next time I hope to visit with
you.
I will be back.

Regards,
Alex Russell
*----------------------------------------------------*
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
*----------------------------------------------------*




-----------------------------------------------------------------
List archives located at: https://mail.dcsol.com/login
username "rebel" password "builder"
Unsubscribe: rebel-builders-unsubscribe@dcsol.com
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