The Murphy Builders Site

Posted: **Fri Feb 17, 2012 9:39 pm**

Hi All
Just a quick update on my Rebel and 1800 amphib floats. I am doing the final prep work ( deburing, painting ect. )on the bottom of the second float and hope to do the installation on the airframe around the first of March. During the float construct ion I spent a considerable amount of time analyzing and remachining the landing gear and gear support structure in a effort to save weight. I also did the hyd. system in aircraft quality tubing, fittings and hoses for a weight savings of 7 lbs per float on th e gear and about 2 lbs on the hyd. system.
On the airframe installation I will be narrowing the float spread about 8 inchs and lowering the airframe to be more in line with the super cub / 172 ect. After initial flight testing I will replace the SS flying wires with stream line wires and install f airing at all strut intersections in a effort to increase performance.

In getting my Rebel ready for the float installation I have installed a inflight adjustable propeller using a Hartzell HC-C2YF-1BF propeller with 7663A-4 blades and a electric drive motor and gear box of my own design that bolts on to the propeller hyd. p iston. This installation allows me to get 2700 rpm static and adjust the pitch to any RPM/ power setting I want inflight. The weight increase over the Sensenich 72-56 propeller that was removed is 14 lbs plus 3 lbs lead in the tail to keep the empty weight C/ G at 10 inches. Flight testing to date has shown a marked decrease in the takeoff roll, a nice increase in the R/C, and better high Alt cruise speeds.

Steve Sloan 536R

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Posted: **Fri Feb 17, 2012 9:39 pm**

Neat stuff, Steve !!! I'm continually impressed with your
efforts to lighten and streamline the Rebel. Please continue to keep
us posted on your progress....... I suspect there'd be MANY takers
for more info on that prop ! Where, how, how much, etc. ....

There's probably a big market for those things !!

(If you were looking for something to fill your time ... ;-) :-) )

....bobp

---------------------------------orig.--------------------------------
At 03:49 PM 1/29/02 EST, you wrote:

Hi All
Just a quick update on my Rebel and 1800 amphib floats. I am doing the final
prep work ( deburing, painting ect. )on the bottom of the second float and
hope to do the installation on the airframe around the first of March. During
the float construction I spent a considerable amount of time analyzing and
remachining the landing gear and gear support structure in a effort to save
weight. I also did the hyd. system in aircraft quality tubing, fittings and
hoses for a weight savings of 7 lbs per float on the gear and about 2 lbs on
the hyd. system.
On the airframe installation I will be narrowing the float spread about 8
inchs and lowering the airframe to be more in line with the super cub / 172
ect. After initial flight testing I will replace the SS flying wires with
stream line wires and install fairing at all strut intersections in a effort
to increase performance.

In getting my Rebel ready for the float installation I have installed a
inflight adjustable propeller using a Hartzell HC-C2YF-1BF propeller with
7663A-4 blades and a electric drive motor and gear box of my own design that
bolts on to the propeller hyd. piston. This installation allows me to get
2700 rpm static and adjust the pitch to any RPM/ power setting I want
inflight. The weight increase over the Sensenich 72-56 propeller that was
removed is 14 lbs plus 3 lbs lead in the tail to keep the empty weight C/G at
10 inches. Flight testing to date has shown a marked decrease in the takeoff
roll, a nice increase in the R/C, and better high Alt cruise speeds.

Steve Sloan 536R
<HTML>Hi All
 Just a quick update on my Rebel  and 1800 amphib floats. I am

doing the final prep work ( deburing, painting ect. )on the bottom of the
second float and hope to do the installation on the airframe around the
first of March. During the float construct

ion I spent a considerable amount of time analyzing and remachining the

landing gear and gear support structure in a effort to save weight. I also
did the hyd. system in aircraft quality tubing, fittings and hoses for a
weight savings of 7 lbs per float on th

e gear and about 2 lbs on the hyd. system.
 On the airframe installation I will be narrowing the float spread about

8 inchs and lowering the airframe to be more in line with the super cub /
172 ect. After initial flight testing I will replace the SS flying wires
with stream line wires and install f

airing at all strut intersections in a effort to increase performance.
 
 In getting my Rebel ready for the float installation I have installed a

inflight adjustable propeller using a Hartzell HC-C2YF-1BF propeller with
7663A-4 blades and a electric drive motor and gear box of my own design that
bolts on to the propeller hyd. p

iston. This installation allows me to get 2700 rpm static and adjust the

pitch to any RPM/ power setting I want inflight. The weight increase over
the Sensenich 72-56 propeller that was removed is 14 lbs plus 3 lbs lead in
the tail to keep the empty weight C/

G at 10 inches. Flight testing to date has shown a marked decrease in the

takeoff roll, a nice increase in the R/C, and better high Alt cruise speeds.

Steve Sloan 536R</HTML>

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Posted: **Fri Feb 17, 2012 9:39 pm**

Hi Steve
What's to be gained by narrowing the float stance and lowering the
plane? I'm just a newly minted float pilot but I sure wasn't impressed by
the 172's performance on edo floats.
Drew

At 03:49 PM 1/29/2002 EST, you wrote:

Hi All
and 1800 amphib floats. I am doing the final prep work ( deburing,
painting ect. )on the bottom of the second float and hope to do the
installation on the airframe around the first of March. During the float
construct ion I spent a considerable amount of time analyzing and
remachining the landing gear and gear support structure in a effort to save
weight. I also did the hyd. system in aircraft quality tubing, fittings and
hoses for a weight savings of 7 lbs per float on th e gear and about 2 lbs
on the hyd. system.
On the airframe installation I will be narrowing the float spread about 8
inchs and lowering the airframe to be more in line with the super cub / 172
ect. After initial flight testing I will replace the SS flying wires with
stream line wires and install f airing at all strut intersections in a
effort to increase performance.

In getting my Rebel ready for the float installation I have installed a
inflight adjustable propeller using a Hartzell HC-C2YF-1BF propeller with
7663A-4 blades and a electric drive motor and gear box of my own design
that bolts on to the propeller hyd. p iston. This installation allows me
to get 2700 rpm static and adjust the pitch to any RPM/ power setting I
want inflight. The weight increase over the Sensenich 72-56 propeller that
was removed is 14 lbs plus 3 lbs lead in the tail to keep the empty weight
C/ G at 10 inches. Flight testing to date has shown a marked decrease in
the takeoff roll, a nice increase in the R/C, and better high Alt cruise
speeds.

Steve Sloan 536R

-----------------------------------------------------

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Posted: **Fri Feb 17, 2012 9:39 pm**

Drew

It's my opinion that the Rebel just looks to high on the Murphy floats. With that said there are some valid reasons for narrowing the spread and lowering the airframe.
First:, narrowing the float spread should help in lifting/breaking the float from the water with the aileron.
Second:, To lower the Airframe it is necessary to narrow the float spread to keep the proper geometry.
Third:, By narrowing the float spread and lowering the airframe you will be using less spreader and strut material which will save weight and should cut down on the airframe drag.

I am not to concerned about the erosion on the propeller due to the lowering of the airframe because I am limited to 72 inch dia. due to the 2800 RPM red line and tip speed. And interesting note in checking the verious float installations, I found the Reb el had one of the widest spreads wider the many of the 180/185 installations.

Steve Sloan 536R

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Posted: **Fri Feb 17, 2012 9:39 pm**

Thanks Steve please let us all know how it works out. I find it enough of a
challenge just to build to the plans. Every imorovement that I've made has
added tons of building time and I want to get my floats finished. I'm glad
theres guys like you that are willing to experiment and share your findings.
Drew

At 02:34 PM 1/30/2002 EST, you wrote:

Drew

It's my opinion that the Rebel just looks to high on the Murphy floats.
With that said there are some valid reasons for narrowing the spread and
lowering the airframe.
First:, narrowing the float spread should help in lifting/breaking the
float from the water with the aileron.
Second:, To lower the Airframe it is necessary to narrow the float spread
to keep the proper geometry.
Third:, By narrowing the float spread and lowering the airframe you will be
using less spreader and strut material which will save weight and should
cut down on the airframe drag.

I am not to concerned about the erosion on the propeller due to the
lowering of the airframe because I am limited to 72 inch dia. due to the
2800 RPM red line and tip speed. And interesting note in checking the
verious float installations, I found the Reb el had one of the widest
spreads wider the many of the 180/185 installations.

Steve Sloan 536R

-----------------------------------------------------

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Posted: **Fri Feb 17, 2012 9:39 pm**

Steve, you have certainly gone a lot further than most of us with weight and drag reduction, and I greatly applaud and respect your accomplishments. I am curious about your statement, though, that a narrower float stance should help in lifting/breaking the float from the water with the aileron. I would have thought the opposite, where a wider stance would lift one float more with the same amount of wing lift. The extreme of this would be a single float system which would not lift at all with aileron. Not sure what I am missing here. Perhaps the leverage of a narrower stance might require less lift to break the suction, but not sure if that would balance out the advantage of more vertical lift of a float for a given amount of wing lift. Just curious... One thing that I do like with my Rebel on floats with the wider stance, is more stability in swells when taxing and making that last turn into the wind for take off. A narrower stance would make my upwind wing rise higher on a swell and increase my chances of getting flipped over. I used to fly an ultralight on floats, and I had it up on one float more than once before getting the turn completed. It is not a good feeling.

-----Original Message-----
From: murphy-rebel@dcsol.com [mailto:murphy-rebel@dcsol.com]On Behalf Of SWSLOANLK@aol.com
Sent: Wednesday, January 30, 2002 11:35 AM
To: murphy-rebel@dcsol.com
Subject: Re: Project Update

Drew

It's my opinion that the Rebel just looks to high on the Murphy floats. With that said there are some valid reasons for narrowing the spread and lowering the airframe.
First:, narrowing the float spread should help in lifting/breaking the float from the water with the aileron.
Second:, To lower the Airframe it is necessary to narrow the float spread to keep the proper geometry.
Third:, By narrowing the float spread and lowering the airframe you will be using less spreader and strut material which will save weight and should cut down on the airframe drag.

I am not to concerned about the erosion on the propeller due to the lowering of the airframe because I am limited to 72 inch dia. due to the 2800 RPM red line and tip speed. And interesting note in checking the verious float installations, I found the Reb el had one of the widest spreads wider the many of the 180/185 installations.

Steve Sloan 536R

Posted: **Fri Feb 17, 2012 9:47 pm**

Walter
You have a vaild point and with every change we make to the origional design it creates a series of compormises. It is my belief that I will obtain a little more leverage with the narrower stance. As far as the water stability, I do not think it will chan ge much as the vertical CG is also lower and with the installation of the 1800 rather than the 1500 on my 1450 Lb gross rebel, this puts me in a OVERFLOAT condition. The experts tend to agree that a overfloat condition within certian limits enhances the water handling. I agree with them on this as I have had the pleasure of flying with a great number of pilots in many different types of float planes during the 35 years of my business travels in S.E. Alaska.
If this combination does not work out I can always purchase new strut/spreader material and correct to the standard Murphy dimensions and belive me!!! this would not be the first time that I have had to go back to square one on changes that I have made.
Steve Sloan 536R

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Posted: **Fri Feb 17, 2012 9:47 pm**

Yes, the lower vertical c of g should help offset that a bit. However, your upwind wing will still raise more in a swell exposing it to gusts, just because of the narrower stance. Anyway, sounds like you know what you're doing and look forward to hearing how it works out. I didn't realize your plane was only 1450 gross. My 1800 amphib installation added almost 300 pounds net weight to my bungee gear version, so will be interesting to hear how much weight you can lop off your float installation.. Anyway, best of luck.

-----Original Message-----
From: murphy-rebel@dcsol.com [mailto:murphy-rebel@dcsol.com]On Behalf Of SWSLOANLK@aol.com
Sent: Sunday, February 03, 2002 12:49 PM
To: murphy-rebel@dcsol.com
Subject: Project Update

Walter
You have a vaild point and with every change we make to the origional design it creates a series of compormises. It is my belief that I will obtain a little more leverage with the narrower stance. As far as the water stability, I do not think it will chan ge much as the vertical CG is also lower and with the installation of the 1800 rather than the 1500 on my 1450 Lb gross rebel, this puts me in a OVERFLOAT condition. The experts tend to agree that a overfloat condition within certian limits enhances the water handling. I agree with them on this as I have had the pleasure of flying with a great number of pilots in many different types of float planes during the 35 years of my business travels in S.E. Alaska.
If this combination does not work out I can always purchase new strut/spreader material and correct to the standard Murphy dimensions and belive me!!! this would not be the first time that I have had to go back to square one on changes that I have made.
Steve Sloan 536R

Posted: **Fri Feb 17, 2012 9:47 pm**

Walter:
A 300 lb increase has got me nervous. I am hoping for only a 200 lb net increase making my empty weight Just under 1100 lbs.( AC 892 lb plus 243 lb floats less 18 lb gear work less 25 lb fairings )
It would be helpful if I could get your AC empty weight empty CG and preformance spec. before and after the float installation.

Steve Sloan

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Posted: **Fri Feb 17, 2012 9:47 pm**

Steve, FYI, and everyone else's, here are Howard's #'s when I put his on 1800 Amphibs.

Floats weighed 258lbs c/w spreaders/struts and all rigging except steps.
Steps probably added about 8lbs.
Selector valve ~ 2lb
Hydraulic hoses in a/c ~ 4lb
Hand pump ~ 2 lb
Reservoir ~ 1 lb
Gallon of Dextron III ~ 7 lb
that totals about 282 lbs

Removed faired main bungee gear (with die spring struts), JDM wheels and 8 x 6 turf tires = 60lb
Removed wishbone and "v" tubes to clean up = 1lb
Removed tailwheel (Scott 3200) = 8 lb

Therefore floats added approximately 213 pounds to the empty weight in his installation.

You can wipe that sweat from your forehead, now!

Cheers,
Wayne G. O'Shea
www.irishfield.on.ca

----- Original Message -----
From: SWSLOANLK@aol.com (SWSLOANLK@aol.com)
To: murphy-rebel@dcsol.com (murphy-rebel@dcsol.com)
Sent: Sunday, February 03, 2002 7:48 PM
Subject: Re: Project Update

Walter:
A 300 lb increase has got me nervous. I am hoping for only a 200 lb net increase making my empty weight Just under 1100 lbs.( AC 892 lb plus 243 lb floats less 18 lb gear work less 25 lb fairings )
It would be helpful if I could get your AC empty weight empty CG and preformance spec. before and after the float installation.

Steve Sloan

Posted: **Fri Feb 17, 2012 9:47 pm**

Yeah, they were a little heavier than I expected, too. My empty weight on wheels was 908, and went to 1200 with the amphibs for a 292 pound net increase. The two wheels with gear and the tail wheel removed weighed exactly 50 pounds. I did leave the front cross bars and steel tail spring on, so potentially could have removed maybe another 7 or 10 pounds. The c of g stayed pretty well the same.

My floats were prebuilt in the Philippines and weighed 130 pounds each, without spreader bars and struts.

I will say that my weighing may not be 100 % accurate with the scales I was using, but I think they were pretty close. My initial empty weight at 908 was also before any fuel had ever been put in the tanks, and the weighing with the floats had as much fuel removed from the tanks as I could. However, there may have been some residual fuel trapped in the separate tank sections.

-----Original Message-----
From: murphy-rebel@dcsol.com [mailto:murphy-rebel@dcsol.com]On Behalf Of SWSLOANLK@aol.com
Sent: Sunday, February 03, 2002 4:49 PM
To: murphy-rebel@dcsol.com
Subject: Re: Project Update

Walter:
A 300 lb increase has got me nervous. I am hoping for only a 200 lb net increase making my empty weight Just under 1100 lbs.( AC 892 lb plus 243 lb floats less 18 lb gear work less 25 lb fairings )
It would be helpful if I could get your AC empty weight empty CG and preformance spec. before and after the float installation.

Steve Sloan

Posted: **Fri Feb 17, 2012 10:04 pm**

Hi All

For the past two weeks I have not been able to fly my Rebel, and to make things worse the weather for the past week has been clear and sunny. But on the bright side my Rebel is now attached to my now completed 1800 amphib's. I still have some hydraulic's to do and rig the water rudders. In another week or two we should be flying again.

I have uploaded a photo to the Rebel airplane section for your viewing.

Steve Sloan 536R

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Posted: **Fri Feb 17, 2012 10:04 pm**

Congrats. Pretty sleek looking Rebel, even with the floats. Will be interested to hear how much you added to your empty weight. Nice to see another Rebel on floats in the NW and at Arlington in July.

-----Original Message-----
From: murphy-rebel@dcsol.com [mailto:murphy-rebel@dcsol.com]On Behalf Of SWSLOANLK@aol.com
Sent: Thursday, April 04, 2002 4:07 PM
To: murphy-rebel@dcsol.com
Subject: Project Update

Hi All

For the past two weeks I have not been able to fly my Rebel, and to make things worse the weather for the past week has been clear and sunny. But on the bright side my Rebel is now attached to my now completed 1800 amphib's. I still have some hydraulic's to do and rig the water rudders. In another week or two we should be flying again.

I have uploaded a photo to the Rebel airplane section for your viewing.

Steve Sloan 536R

Posted: **Fri Feb 17, 2012 10:04 pm**

Sweet! Nice Rebel.

Steve when you get a chance would you please post figures detailing how tall your Rebel is on the 1800's?

Thanks,
Dave

Hi All

For the past two weeks I have not been able to fly my Rebel, and to make things worse the weather for the past week has been clear and sunny. But on the bright side my Rebel is now attached to my now completed 1800 amphib's. I still have some hydraulic's to do and rig the water rudders. In another week or two we should be flying again.
I have uploaded a photo to the Rebel airplane section for your viewing.
Steve Sloan 536R

--

Posted: **Fri Feb 17, 2012 10:04 pm**

Looks good Steve! You sure shortened those vertical struts up! Were you able to still use the supplied MAM front attach blocks, by tweaking (angling) their location in the front struts, or did you have to make new ones up with a sharper angle on them??

Regards,
Wayne

----- Original Message -----
From: SWSLOANLK@aol.com (SWSLOANLK@aol.com)
To: murphy-rebel@dcsol.com (murphy-rebel@dcsol.com)
Sent: Thursday, April 04, 2002 7:07 PM
Subject: Project Update

Hi All

For the past two weeks I have not been able to fly my Rebel, and to make things worse the weather for the past week has been clear and sunny. But on the bright side my Rebel is now attached to my now completed 1800 amphib's. I still have some hydraulic's to do and rig the water rudders. In another week or two we should be flying again.

I have uploaded a photo to the Rebel airplane section for your viewing.

Steve Sloan 536R