KR> weight and balance

[Oscar Zuniga]

Jon wrote-

> It's quoted as 15 to 35 percent of the mac...which I believe is 41 inches
> for the stock kr2...less for the kr2s. 

(Insert the sound of me slapping my hand to my forehead here)- why wasn't I 
paying attention?  The KR2 wing is *not* constant chord for most of its span, 
so the MAC is certainly not 48" just because that's what the chord is at the 
center section!  My bad.

Re-stated then, and using 41" as the MAC, a CG range of 15 to 35% would be 
6.15" to 14.35"... a range of 8.2".  Now it makes sense when Neil Bingham 
writes in his "A Critical Analysis of the KR2" that in his opinion, the stated 
8" range should be reduced to a 6" range, with 2" being taken off the aft end 
of the range.  The numbers all make sense now; thank you Jon!

Oscar Zuniga
Medford, OR

KR> weight and balance

[Lee Parker]

My KR was out of the CG range until I sat in the seat which brought it to 
within the CG. range. ?I always kelp a little weight to throw in the back to 
help with CG.

  From: Mark Langford via KRnet 
 To: KRnet  
Cc: ml at n56ml.com
 Sent: Monday, April 4, 2016 1:43 PM
 Subject: Re: KR> weight and balance

Chris Prata wrote:

>If 35% aft from the leading edge (at mean average chord point) is too far aft, 
>what is the commonly accepted safe limit and where in your experience does she 
>fly best?

There's some ambiguity there, as the plans call for 8"-16" from the
leading edge of the stub wing, and the range is quoted as 15%-35%, and
20% of 48" is 7.6", so the numbers don't jive. But let's say take 2" off
of the 16" for simplicity and call it 8" to 14" for an "amended" CG
range, then check the max forward loaded condition (lightest pilot and
full/empty fuel, depending on where your tanks are).? Then calculate
worst case with heavy passengers and aft-most fuel situation? and make
sure you're nowhere near the aft end of the range, adjusting as
necessary to get that range situated toward the middle, or biased toward
the front.? Generally speaking the further aft the CG is, the less
stable it will be.? There are few downsides to a forward CG, being able
to lift the nosewheeel for rotation being one, and having to crank in
some nose up trim (extra drag being the other.? The downside to too far
aft is that the plane is a handful to fly, or, it kills you shortly
after takeoff!

N56ML is slightly forward in the condition that I usually fly it in,
with half fuel, me as pilot, and the usual 20 lbs of crap I carry
(tools, spare radio, camera, etc) sitting on the seat.? I've put some
pretty heavy people in there and it gets a little light on the stick,
but not dangerous, and most people that've flown my plane would call it
quite reasonable.? 

N891JF was set up by Jim Faughn to be right on the forward end of the
range with full fuel and him as pilot.? Needless to say, on my first
flight, I took off with neutral trim and flew it up to cruise altitude
that way.? Then I started checking control reactions and when I let go
of the stick it immediately nose dived!? That's the downside...it needs
trim cranked in.? That won't kill you though.? I have since added a few
things aft (flap, backup battery, APRS, ELT), so it's a little more aft,
and I noticed yesterday that my previous landing after a long cruise
back home, the trim tab was level with the elevator, so I'm flying it
"typically" with no up or down trim now, and it's quite fine...but the
heaviest person I've carried is my 100 pound daughter!

See http://www.n56ml.com/wb/index.html for more on what happens if you
go too far aft.? Been there, done that, and don't want to repeat it!

Mark Langford, Harvest, AL
ML "at" N56ML.com
www.N56ML.com


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KR> weight and balance

[jon kimmel]

It's quoted as 15 to 35 percent of the mac...which I believe is 41 inches
for the stock kr2...less for the kr2s.  The point I make is that the
location of the mac is very easy to change in relation to the stub
wing...the as5048 has spar locations that move the mac...and cg range
forward about a half an inch.

https://sites.google.com/site/mykr2stretch/
https://sites.google.com/site/mykr2stretch/parts-for-sale

KR> weight and balance

[Chris Prata]

mark if 35% aft from leading edge (at mean average chord point?) is too far 
aft, what is the commonly accepted safe limit and where in your experience does 
she fly best?



> To: krnet at list.krnet.org
> Date: Sun, 3 Apr 2016 19:28:49 -0700
> Subject: Re: KR> weight and balance
> From: krnet at list.krnet.org
> CC: ML at N56ML.com
> 
> 
> Gary wrote:
> 
> > From my plans, the CG is 15% to 40% of the wing chord.  That was the old
> > wing.   Is it the same with to AS5048 wing?
> 
> I don't ever remember seeing that number before. Is that for a KR1, or just
> an early set of plans?  My plans also say 15%-35%, and that's the range that
> extends too far aft to be safe (according to an analysis by Richard Mole and
> also experience by pilots).  The AS50xx series airfoils are designed to have
> a similar lift coefficient and range (15%-35%) as the RAF 48 (minus those
> aft two inches).
> 
> Mark Langford
> ML at N56ML.com
> http://www.n56ml.com
> 
> 
> ___
> Search the KRnet Archives at http://tugantek.com/archmailv2-kr/search.
> To UNsubscribe from KRnet, send a message to KRnet-leave at list.krnet.org
> please see other KRnet info at http://www.krnet.org/info.html
> see http://list.krnet.org/mailman/listinfo/krnet_list.krnet.org to change 
> options

KR> weight and balance

[ml at n56ml.com]

Chris Prata wrote:

>If 35% aft from the leading edge (at mean average chord point) is too far aft, 
>what is the commonly accepted safe limit and where in your experience does she 
>fly best?

There's some ambiguity there, as the plans call for 8"-16" from the
leading edge of the stub wing, and the range is quoted as 15%-35%, and
20% of 48" is 7.6", so the numbers don't jive. But let's say take 2" off
of the 16" for simplicity and call it 8" to 14" for an "amended" CG
range, then check the max forward loaded condition (lightest pilot and
full/empty fuel, depending on where your tanks are).  Then calculate
worst case with heavy passengers and aft-most fuel situation  and make
sure you're nowhere near the aft end of the range, adjusting as
necessary to get that range situated toward the middle, or biased toward
the front.  Generally speaking the further aft the CG is, the less
stable it will be.  There are few downsides to a forward CG, being able
to lift the nosewheeel for rotation being one, and having to crank in
some nose up trim (extra drag being the other.  The downside to too far
aft is that the plane is a handful to fly, or, it kills you shortly
after takeoff!

N56ML is slightly forward in the condition that I usually fly it in,
with half fuel, me as pilot, and the usual 20 lbs of crap I carry
(tools, spare radio, camera, etc) sitting on the seat.  I've put some
pretty heavy people in there and it gets a little light on the stick,
but not dangerous, and most people that've flown my plane would call it
quite reasonable.  

N891JF was set up by Jim Faughn to be right on the forward end of the
range with full fuel and him as pilot.  Needless to say, on my first
flight, I took off with neutral trim and flew it up to cruise altitude
that way.  Then I started checking control reactions and when I let go
of the stick it immediately nose dived!  That's the downside...it needs
trim cranked in.  That won't kill you though.  I have since added a few
things aft (flap, backup battery, APRS, ELT), so it's a little more aft,
and I noticed yesterday that my previous landing after a long cruise
back home, the trim tab was level with the elevator, so I'm flying it
"typically" with no up or down trim now, and it's quite fine...but the
heaviest person I've carried is my 100 pound daughter!

See http://www.n56ml.com/wb/index.html for more on what happens if you
go too far aft.  Been there, done that, and don't want to repeat it!

Mark Langford, Harvest, AL
ML "at" N56ML.com
www.N56ML.com

KR> weight and balance

[Mark Langford]

Gary wrote:

> From my plans, the CG is 15% to 40% of the wing chord.  That was the old
> wing.   Is it the same with to AS5048 wing?

I don't ever remember seeing that number before. Is that for a KR1, or just
an early set of plans?  My plans also say 15%-35%, and that's the range that
extends too far aft to be safe (according to an analysis by Richard Mole and
also experience by pilots).  The AS50xx series airfoils are designed to have
a similar lift coefficient and range (15%-35%) as the RAF 48 (minus those
aft two inches).

Mark Langford
ML at N56ML.com
http://www.n56ml.com

KR> weight and balance

[Pete Klapp]

 Gary 
My plans manual, ss# 1216, list 15% to 35% MAC for RAF 48 airfoil. I used Diehl 
skins on my project.
 Pete
To: krnet at list.krnet.org
List-Post: krnet@list.krnet.org
Date: Sat, 2 Apr 2016 19:59:48 -0500
Subject: Re: KR> weight and balance
From: krnet at list.krnet.org
CC: gary769rv at verizon.net

>From my plans, the CG is 15% to 40% of the wing chord.  That was the old wing.

Is it the same with to AS5048 wing?








Gary

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KR> weight and balance

[Pete Klapp]

Larry 
Thanks for the link for the weight and balance handbook.
I've been using the formulas from AC 91-23 DOT manual.
I ran more numbers using several datums: aft of the main gear, several inches 
out in front of the spinner, and the prop flange. 
All the numbers come out good. Empty CG's fall fwd of the RR CG range. When I 
put in values for me, a passenger, various fuel quantities,  baggage in various 
configurations, all the "flying CG's" fell within an 1.75 to 3.5" aft of the RR 
CG range, resulting in a total of about 1.75" change from me and 1/2 fuel to 
max gross wt. Everything fell very close to the middle or better of the 
"preferred 6" CG range". 
Looks like I can move the engine between 2 to 3" fwd of where a WW engine mount 
would locate a Corvair engine.
Thanks for your help and insight.
Pete


> Date: Sat, 2 Apr 2016 12:42:15 -0500
> To: krnet at list.krnet.org
> Subject: KR> weight and balance
> From: krnet at list.krnet.org
> CC: flesner at frontier.com
> 
> 
> >
> 
> Here is everything you need to know about weight and balance:
> 
> https://www.faa.gov/regulations_policies/handbooks_manuals/aircraft/media/FAA-H-8083-1A.pdf
>  
> 
> 
> ___
> Search the KRnet Archives at http://tugantek.com/archmailv2-kr/search.
> To UNsubscribe from KRnet, send a message to KRnet-leave at list.krnet.org
> please see other KRnet info at http://www.krnet.org/info.html
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> options

KR> weight and balance

[Gary]

>From my plans, the CG is 15% to 40% of the wing chord.  That was the old wing.

Is it the same with to AS5048 wing?








Gary
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KR> weight and balance

[Larry Flesner]

At 12:18 PM 4/2/2016, you wrote:
>What's a weight and balance?
>Mike Stirewalt
>

Here is everything you need to know about weight and balance:

https://www.faa.gov/regulations_policies/handbooks_manuals/aircraft/media/FAA-H-8083-1A.pdf
 

KR> weight and balance

[John Martindale]

Hi Sid

It is not that the centre of lift for the RAF48 wing has been inaccurately
mapped. That would have been well calculated by the wing designers (not Stu
Robinson) and has little or nothing to do with the aircraft it is put on.
Rather the issue is that the CoG envelope for the KR2 was set too broadly
and perhaps somewhat arbitrarily at 8" to 16".

We know that flight in the rear 2" or so has whiskers on it and in fact in
Australia in the early days the authorities downright banned it.

However, this does not mean that the forward limit at 8" is also incorrect.
I think reducing it to 6" may be ill advised without proper analysis and you
may find difficulty in raising the nose at low airspeeds such as in the
flare.

As I have explained previously you cannot simply equate Centre of Lift with
Centre of Gravity because the balance is the outcome of four vectors, the
other two being thrust and drag. Further, the CoL varies with Angle of
Attack and at the stall moves backwards lending support to a nose down
tendency that aids in recovery. If the CoL is actually 2" further forward as
you claim then this design aspect would be compromised.

I suspect the problem with your aircraft is not the CoL but the fact that it
was tail heavy and too far back in the envelope as you have correctly
addressed. It is not necessarily to do with an inaccurate mapping of the
CoL. Please do not blame the designer for what is essentially a construction
error. There are many KR2s flying without a problem and have been for years.


Cheers John

John Martindale
29 Jane Circuit
Toormina NSW 2452
Australia

ph:61 2 6658 4767
m:0403 432179
email:john_martindale at bigpond.com
web site: 

-Original Message-
From: KRnet [mailto:krnet-bounces at list.krnet.org] On Behalf Of Sid Wood via
KRnet
Sent: Wednesday, 19 August 2015 5:54 AM
To: krnet at list.krnet.org
Cc: Sid Wood
Subject: Re: KR> weight and balance

The KR-2 Plans have a serious error regarding Weight & Balance.  The 
designer, Stu Robinson, chose the RAF48 Center
of Lift 2 inches to far forward..snip



-
No virus found in this message.
Checked by AVG - www.avg.com
Version: 2015.0.6125 / Virus Database: 4401/10469 - Release Date: 08/19/15

KR> weight and balance

[Sid Wood]

The KR-2 Plans have a serious error regarding Weight & Balance.  The 
designer, Stu Robinson, chose the RAF48 Center
of Lift 2 inches to far forward.  The KR-2S supplement does correct this 
error.
Here is an excerpt from the archives: http://www.krnet.org/as504x/
--
There are three different ways to use the new airfoil. For new construction, 
the best is probably using the 18% AS5048 at the root, tapering to the 15% 
AS5045 at the tip. This uses a main spar that is 8.19" tall at the root, 
making it 17% stronger than the stock spar. It also adds almost 20% to the 
capacity of the wing tanks. The materials required are exactly the same as 
the plans call for, except the vertical spacers between the caps are 
slightly longer. If your spars are already built, the 16% AS5046 is almost a 
perfect match, requiring only a lamination of 1/8" of spruce to the upper 
main spar cap to bring it up to proper dimension.
-
If you use the KR-2 Plans dimensions as is and the
location called out for the VW engine, your KR-2 will have an extremely poor
aft CG problem.  Big engines such as a Corvair or O-200 with the heavier
weights up front and/or extended engine mounts will solve the problem.  The
CG range numbers called out in the stock KR-2 Plans are wrong.  Numbers
should be 6 to 14 inches.

Sid Wood
Tri-gear KR-2 N6242
Mechanicsville, MD, USA

PS: Sorry about my previous post; hit the send button instead of the paste.
-

The plans call for using 8 inches - 16 inches of the wing cord. So forward
point would be 8 inches aft of the wings front edge. Aft would be 16 inches.
This is for the RAF 48 airfoil.
I wonder if the new airfoil would be different

--

Most aircraft use 15% to 35% mac.  The forward limit is influenced by the
distance to the horizontal and size.  The aft limit is not.  I think most
go wrong in the mac.  The mac for a kr2s is slightly smaller than for a KR2
and the plans are for a kr2.   The governing factors are taper and sweep.
You can measure both easily.  Something I found interesting with the new
airfoil is that it looks like the sweep is different than what is in the
plans.

https://sites.google.com/site/mykr2stretch/
https://sites.google.com/site/mykr2stretch/parts-for-sale
On Aug 17, 2015 5:40 PM, "Chris Prata via KRnet" 
wrote:

> The plans call for using 8 inches - 16 inches of the wing cord. So forward
> point would be 8 inches aft of the wings front edge. Aft would be 16
> inches.
> This is for the RAF 48 airfoil.
> I wonder if the new airfoil would be different
>

KR> weight and balance

[Chris Prata]

The plans call for using 8 inches - 16 inches of the wing cord. So forward
point would be 8 inches aft of the wings front edge. Aft would be 16 inches.
This is for the RAF 48 airfoil.
I wonder if the new airfoil would be different

KR> weight and balance

[jon kimmel]

Most aircraft use 15% to 35% mac.  The forward limit is influenced by the
distance to the horizontal and size.  The aft limit is not.  I think most
go wrong in the mac.  The mac for a kr2s is slightly smaller than for a KR2
and the plans are for a kr2.   The governing factors are taper and sweep.
You can measure both easily.  Something I found interesting with the new
airfoil is that it looks like the sweep is different than what is in the
plans.

https://sites.google.com/site/mykr2stretch/
https://sites.google.com/site/mykr2stretch/parts-for-sale
On Aug 17, 2015 5:40 PM, "Chris Prata via KRnet" 
wrote:

> The plans call for using 8 inches - 16 inches of the wing cord. So forward
> point would be 8 inches aft of the wings front edge. Aft would be 16
> inches.
> This is for the RAF 48 airfoil.
> I wonder if the new airfoil would be different
>
> ___
> Search the KRnet Archives at http://tugantek.com/archmailv2-kr/search.
> To UNsubscribe from KRnet, send a message to KRnet-leave at list.krnet.org
> please see other KRnet info at http://www.krnet.org/info.html
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> options
>

KR> weight and balance

[stefkr2 at kpnmail.nl]

Hi guys,
Monday we will do a weight and balance check to calculate the engine position. 
We did build a KR-2 but did extend the tail like an kr2-s,  have the old kr2 
wings but with the extension like the kr2-s. Fire wall is reinforced for the 
more powerful engine but have no two inch extension to the front. Can you guys 
give me the advice what you should use for the fwd and aft gravity point? I 
think I can use the drawing dimensions. Result will be more space after the 
engine.
Stef 
--
Steph and his dad are building the KR-2S see   
http://www.masttotaalconcept.nl/kr2

KR> weight and balance

[Rob Schmitt]

The plans call for using 8 inches - 16 inches of the wing cord. So forward 
point would be 8 inches aft of the wings front edge. Aft would be 16 inches. 
This is for the RAF 48 airfoil.

Rob Schmitt
N1852Z

> On Aug 15, 2015, at 7:11 AM, Flesner via KRnet  
> wrote:
> 
> 
>> . Can you guys give me the advice what you should use for the fwd and aft 
>> gravity point? I think I can use the drawing dimensions. Result will be more 
>> space after the engine.
>> Stef
> 
> 
> Stef,
> 
> You and your dad have done some fine work on your KR.
> 
> Use the CG location established in the plans but don't use the rear two 
> inches of the CG.  The CG is based on the wing plan form, not what is 
> attached to the wing.  It is based on the center of lift for that wing shape. 
>  Place your engine to keep you in the CG range with different loading 
> configurations. More forward is best.
> 
> Larry Flesner  
> 
> ___
> Search the KRnet Archives at http://tugantek.com/archmailv2-kr/search.
> To UNsubscribe from KRnet, send a message to KRnet-leave at list.krnet.org
> please see other KRnet info at http://www.krnet.org/info.html
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> options

KR> weight and balance

[Dan Heath]

I used the firewall, figuring that, that location would never change.

My Panther Building Documentation at PantherBuilder Web Site

Daniel R. Heath -?Lexington, SC

-Original Message-
From: KRnet [mailto:krnet-bounces at list.krnet.org] On Behalf Of stefkr2---
via KRnet
Sent: Saturday, August 15, 2015 6:47 AM
To: Kr net Kr net
Cc: stefkr2 at kpnmail.nl
Subject: KR> weight and balance

Hi guys,
Monday we will do a weight and balance check to calculate the engine
position. We did build a KR-2 but did extend the tail like an kr2-s,  have
the old kr2 wings but with the extension like the kr2-s. Fire wall is
reinforced for the more powerful engine but have no two inch extension to
the front. Can you guys give me the advice what you should use for the fwd
and aft gravity point? I think I can use the drawing dimensions. Result will
be more space after the engine.
Stef
--
Steph and his dad are building the KR-2S see
http://www.masttotaalconcept.nl/kr2


___
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options

KR> weight and balance

[Flesner]

>. Can you guys give me the advice what you should use for the fwd 
>and aft gravity point? I think I can use the drawing dimensions. 
>Result will be more space after the engine.
>Stef


Stef,

You and your dad have done some fine work on your KR.

Use the CG location established in the plans but don't use the rear 
two inches of the CG.  The CG is based on the wing plan form, not 
what is attached to the wing.  It is based on the center of lift for 
that wing shape.  Place your engine to keep you in the CG range with 
different loading configurations. More forward is best.

Larry Flesner  

KR> weight and balance

[jon kimmel]

15% to 35% Mac is a good estimate.  You should
recalculate hour Mac as it sounds like this is a unique configuration.

https://sites.google.com/site/mykr2stretch/
https://sites.google.com/site/mykr2stretch/parts-for-sale

KR> weight and balance

[Mac McConnell-Wood]

Yes- I recall Dan Dhiel (sorry for spelling Dan) back in the '80's talking
about doing just that...he physically balanced his KR on a roller
mounted on trestles in order to verify the c of g location.

Mac Wood

On Thu, May 21, 2015 at 9:06 PM, dfeiger via KRnet 
wrote:

> Question: has anyone tried balancing a KR to see if it is correct?
>
> Before my first flight of my mostly stock KR2 on September 28, 1984.  I
> built a small wood cradle that supported the fuselage at the outer fuselage
> edges, tied it for and aft so it could not slip, and placed a large dowel
> cross wise at the design CG. This set on a sturdy stand and with the
> aircraft tethered for and aft with enough slack to allow about a four inch
> up/down tilt at the spinner nose. With the aircraft in a ready to fly setup
> but without any fuel I got in and found that by leaning fore ward and aft I
> could rock it. With the landing gear in the up position I had to lean only
> slightly more fore ward to get it to tilt ahead. This confirmed my weight
> and balance calculations and removed all doubt to that fact before first
> flight.
>
> With 30 1/2 years and 1496.7 logged hours on KR2 N39426 to date the above
> proved to be exact.
>
> ___
> Search the KRnet Archives at http://tugantek.com/archmailv2-kr/search.
> To UNsubscribe from KRnet, send a message to KRnet-leave at list.krnet.org
> please see other KRnet info at http://www.krnet.org/info.html
> see http://list.krnet.org/mailman/listinfo/krnet_list.krnet.org to change
> options
>

KR> weight and balance

[dfeiger]

Question: has anyone tried balancing a KR to see if it is correct?

Before my first flight of my mostly stock KR2 on September 28, 1984.  I built a 
small wood cradle that supported the fuselage at the outer fuselage edges, tied 
it for and aft so it could not slip, and placed a large dowel cross wise at the 
design CG. This set on a sturdy stand and with the aircraft tethered for and 
aft with enough slack to allow about a four inch up/down tilt at the spinner 
nose. With the aircraft in a ready to fly setup but without any fuel I got in 
and found that by leaning fore ward and aft I could rock it. With the landing 
gear in the up position I had to lean only slightly more fore ward to get it to 
tilt ahead. This confirmed my weight and balance calculations and removed all 
doubt to that fact before first flight.

With 30 1/2 years and 1496.7 logged hours on KR2 N39426 to date the above 
proved to be exact.

KR> Weight and balance

[Flesner]

At 07:26 PM 5/20/2015, you wrote:
>Has anyone ever tried to support the airplane under the stub wing and lift
>up on it with the wings
+++

If you accurately weigh and measure the airplane you can "lift the 
airplane" with pencil and paper.

Larry Flesner 

KR> Weight and balance

[CraigW]

Yes I do the same thing with my RC planes.  I have every intention of doing it
before I fly my plane.  Because after all I am human...

Craig
www.kr2seafury.com

Frankenstein Lycoming powered



> On May 20, 2015 at 8:26 PM dean choitz via KRnet  
> wrote:
>
>
> Has anyone ever tried to support the airplane under the stub wing and lift
> up on it with the wings attached tail feathers completed get in the plane
> engine on the firewall fuel empty fuel full that's the way I did it in the
> radio control airplane days or would something break or poke a hole in the
> wing perhaps maybe a support block could be made under the wing to keep
> from pushing through just seems like an easy way to accurately measure your
> weight and balance center of lift any thoughts
> ___
> Search the KRnet Archives at http://tugantek.com/archmailv2-kr/search.
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> options

KR> Weight and balance

[Dave Acklam]

You will punch through and a block will crush foam...

Iirc w is best done with 3 scales, one under each wheel... You can then
calculate cg from the weight diff
On May 20, 2015 5:27 PM, "dean choitz via KRnet" 
wrote:

> Has anyone ever tried to support the airplane under the stub wing and lift
> up on it with the wings attached tail feathers completed get in the plane
> engine on the firewall fuel empty fuel full that's the way I did it in the
> radio control airplane days or would something break or poke a hole in the
> wing perhaps maybe a support block could be made under the wing to keep
> from pushing through just seems like an easy way to accurately measure your
> weight and balance center of lift any thoughts
> ___
> Search the KRnet Archives at http://tugantek.com/archmailv2-kr/search.
> To UNsubscribe from KRnet, send a message to KRnet-leave at list.krnet.org
> please see other KRnet info at http://www.krnet.org/info.html
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> options
>

KR> Weight and balance

[dean choitz]

Has anyone ever tried to support the airplane under the stub wing and lift
up on it with the wings attached tail feathers completed get in the plane
engine on the firewall fuel empty fuel full that's the way I did it in the
radio control airplane days or would something break or poke a hole in the
wing perhaps maybe a support block could be made under the wing to keep
from pushing through just seems like an easy way to accurately measure your
weight and balance center of lift any thoughts

KR> Weight and Balance

[Sid Wood]

Did the first flight on my KR-2 this morning after moving the engine 
2-inches forward from the plans call-out.  (This was the fourth flight on 
this aircraft.)  Weight and balance measurements showed my take-off cg with 
me onboard and half fuel to be 12.6 inches from the stub wing datum.  Plans 
allowable range is 8 to 16 inches.  Seemed to have an adverse aft cg 
apparent at lift off.  Thought it may have been the pitch trim.  That was 
working, but not enough to trim out the stick pressure tending to pitch up. 
Flew around the airport at 3,000 feet for half an hour trying to explore the 
stall and handling characteristics.  Stall was about 40 Kts indicated; 
definitely had a pitch up problem at any speed.  So, did not do a full stall 
break.
On landing wind was 4 Kts quartering from the left.  Had some turbulence at 
touchdown with 50 Kts indicated airspeed.  Instead of the nose pitching down 
with main gear touching as I had expected, the nose pitched up.  I ran out 
of forward elevator authority as the tail skid touched down hard.  That put 
the mains back on the asphalt hard.  Bounced airborne, then did an ugly 
three point landing.  I managed to keep it on the ground, but ran off the 
left side of the runway and stopped in the grass.  The engine had stopped 
some time after the first touch down.  Amazing how suddenly quiet it gets 
when nothing is moving.  The entire landing sequence from first touch to 
full stop took less than 5 seconds, it seemed.  The prop blade sticking 
straight up in front of me looked ok, so I restarted the engine and taxied 
back to the hangar.  I am thankful for that 9-1/2 inch prop ground 
clearance.

Only apparent damage was a scuffed tail skid.
Good news is the oil temperature never exceeded 162 degrees F.  The new 
Revmaster oil cooler system worked ok.

Will definitely revisit the weight and balance, and get the main wheels to 
the correct 20 inch location.  Next flight will be in dead-calm wind 
conditions!

Sid Wood
Tri-gear KR-2 N6242
Mechanicsville, MD, USA

KR> Weight and Balance

[Lawrence Bell]

Glad you made it OK, Sid. Hope you can relocate your wheels without too
much expense and find your pitch up problem.
Larry Bell


On Fri, Aug 29, 2014 at 12:26 PM, Sid Wood via KRnet 
wrote:

> Did the first flight on my KR-2 this morning after moving the engine
> 2-inches forward from the plans call-out.  (This was the fourth flight on
> this aircraft.)  Weight and balance measurements showed my take-off cg with
> me onboard and half fuel to be 12.6 inches from the stub wing datum.  Plans
> allowable range is 8 to 16 inches.  Seemed to have an adverse aft cg
> apparent at lift off.  Thought it may have been the pitch trim.  That was
> working, but not enough to trim out the stick pressure tending to pitch up.
> Flew around the airport at 3,000 feet for half an hour trying to explore
> the stall and handling characteristics.  Stall was about 40 Kts indicated;
> definitely had a pitch up problem at any speed.  So, did not do a full
> stall break.
> On landing wind was 4 Kts quartering from the left.  Had some turbulence
> at touchdown with 50 Kts indicated airspeed.  Instead of the nose pitching
> down with main gear touching as I had expected, the nose pitched up.  I ran
> out of forward elevator authority as the tail skid touched down hard.  That
> put the mains back on the asphalt hard.  Bounced airborne, then did an ugly
> three point landing.  I managed to keep it on the ground, but ran off the
> left side of the runway and stopped in the grass.  The engine had stopped
> some time after the first touch down.  Amazing how suddenly quiet it gets
> when nothing is moving.  The entire landing sequence from first touch to
> full stop took less than 5 seconds, it seemed.  The prop blade sticking
> straight up in front of me looked ok, so I restarted the engine and taxied
> back to the hangar.  I am thankful for that 9-1/2 inch prop ground
> clearance.
>
> Only apparent damage was a scuffed tail skid.
> Good news is the oil temperature never exceeded 162 degrees F.  The new
> Revmaster oil cooler system worked ok.
>
> Will definitely revisit the weight and balance, and get the main wheels to
> the correct 20 inch location.  Next flight will be in dead-calm wind
> conditions!
>
> Sid Wood
> Tri-gear KR-2 N6242
> Mechanicsville, MD, USA
>
>
>
>
> ___
> Search the KRnet Archives at http://tugantek.com/archmailv2-kr/search.
> To UNsubscribe from KRnet, send a message to KRnet-leave at list.krnet.org
> please see other KRnet info at http://www.krnet.org/info.html
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> options
>

KR> weight and balance article

[Larry Flesner]

At 04:44 PM 10/18/2013, you wrote:
>Ok...I'll agree with that...just seems odd that they would use them as an
>example for cg.
++

Maybe they referenced them because they were the FIRST to have a CG 
problem with an airplane. :-)

Larry Flesner

KR> weight and balance article link enclosed

[Larry Flesner]

At 08:23 AM 10/18/2013, you wrote:
>Google wright flyer unstable and you'll find it.  They did it on purpose.
>When asked their coined response was something like the pilot should fly
>the airplane.
++

My only real point was that whatever the Wrights did does not 
discredit the article about what we know to be true now.

Larry Flesner

KR> weight and balance article link enclosed

[Larry Flesner]

At 05:33 AM 10/18/2013, you wrote:
>The article lost some credibility when it referred to the wright
>brotherssince they intentionally made the wright flyer unstable.
++

Where did you learn the Wright's made their Flyer unstable?  It 
wasn't in the article.Even if they did that doesn't take away 
from the credibility of the article.  They were just learning and we 
know better now.  I thought it was pretty much spot on.

Larry Flesner

KR> weight and balance

[Mark Jones]

>Mike wrote:
>If it's within the design CG range, all must be well. I'd feel more 
>comfortable with a smaller change, especially >with a 200+ lb. passenger. 
>Or a good sized trim tab!


If you eliminate the header tank and go with wing tanks you will not have 
that issue. My CG will move only 3/4 inch with passenger and full tanks to 
empty tanks. I have never had a CG issue which concerned me.

Mark Jones (N886MJ)
Stevens Point, WI
E-mail: flyk...@charter.net
Web: www.flykr2s.com

KR> weight and balance

[mike miller]

 "...the (acceptable) CG envelope for flight which is 0 to 6 inches aft of 
the rear face of the forward spar.  It is a balancing act."

Larry Flesner


Thanks, Larry. I don't have plans, just looking at different designs. My 
question arose from looking at photos of what's been built by others.On a 
single seater, no problems...but it looked as if the addition of a passenger 
that far aft of the MAC would cause problems with an already "sensitive" design 
(KR2). If it's within the design CG range, all must be well. I'd feel more 
comfortable with a smaller change, especially with a 200+ lb. passenger. Or a 
good sized trim tab!

Mike

KR> weight and balance

[Dan Heath]

Sorry, I mis-understood the statement.

See N64KR at http://KRBuilder.org - Then click on the pics 
See you at the 2012 - KR Gathering in Mt. Vernon, Il – MVN – 40th
Anniversary
There is a time for building and it is over.
Daniel R. Heath - Lexington, SC


-Original Message-
From: krnet-boun...@mylist.net [mailto:krnet-boun...@mylist.net] On Behalf
Of Larry Flesner
Sent: Saturday, January 07, 2012 7:50 PM
To: KRnet
Subject: RE: KR> weight and balance



>I have not seen that.  Where did you get that information?  Is this on your
>KR or KRs in general?
>Daniel R. Heath
+++

KR> weight and balance

[Larry Flesner]

At 06:50 PM 1/7/2012, you wrote:
>With full fuel (wing tanks only) and me on
>board, my CG falls 4 inches aft of the rear face of the forward spar,
>right in the middle of the CG envelope
++

I should have said " right in the middle of the plans called for CG 
range".  It is generally accepted that the rear 2 inches of the"plans 
called for" CG range should be avoided for safe flight.  Pitch 
control is noticeably more sensitive as you move further aft in the 
CG range. Also, my KR is stretched 24 inches, moving my elevators 
back 24 inches and giving me a bit more elevator authority.  Your 
results may vary.

Larry Flesner

KR> weight and balance

[Larry Flesner]

>I've noticed that the CG for the occupants on the KR2 & KR2S is at least a
>foot behind the airplane balance.


>I have not seen that.  Where did you get that information?  Is this on your
>KR or KRs in general?
>Daniel R. Heath
+++

The majority of the "mass" of pilot and passenger are in fact behind 
the (acceptable) CG envelope for flight which is 0 to 6 inches aft of 
the rear face of the forward spar.  It is a balancing act.  The empty 
CG must be at a point that will allow the fuel, pilot, and passenger 
to bring the "balance point" (CG) for flight into that 0 to 6 inch 
range.  As I recall, my empty CG is one inch, or there about, forward 
of the forward limit.  With full fuel (wing tanks only) and me on 
board, my CG falls 4 inches aft of the rear face of the forward spar, 
right in the middle of the CG envelope.  I could burn off all 25 
gallon of fuel and my CG moves forward one inch as all my fuel is 
basically right in the CG range.  Each KR is different and the flight 
CG for each airplane must be determined for that airplane only.  The 
flight CG must be determined for all possible situations, full fuel, 
near empty fuel, heavy pilot, light pilot, passenger, no passenger, 
baggage, no baggage, etc.  Do it right and fly safe.

Larry Flesner

KR> weight and balance

[Dan Heath]

I have not seen that.  Where did you get that information?  Is this on your
KR or KRs in general?

See N64KR at http://KRBuilder.org - Then click on the pics 
See you at the 2012 - KR Gathering in Mt. Vernon, Il – MVN – 40th
Anniversary
There is a time for building and it is over.
Daniel R. Heath - Lexington, SC



-Original Message-

I've noticed that the CG for the occupants on the KR2 & KR2S is at least a
foot behind the airplane balance. 

KR> weight and balance

[Larry Flesner]

At 04:17 PM 1/7/2012, you wrote:
>I've noticed that the CG for the occupants on the KR2 & KR2S is at 
>least a foot behind the airplane balance. How is this compensated 
>for with and without a passenger? A movable weight, unused fuel or 
>only trim? Thanks, Mike
++

The "empty" CG of the airplane should be located at a point where the 
addition of a pilot, passenger , and fuel put the "loaded" CG inside 
the CG envelope for flight.

Larry Flesner

KR> weight and balance

[mike miller]

I've noticed that the CG for the occupants on the KR2 & KR2S is at least a foot 
behind the airplane balance. How is this compensated for with and without a 
passenger? A movable weight, unused fuel or only trim? Thanks, Mike

KR> Weight and balance at the Gathering

[Dan Heath]

OK, the other scale is in the plane.

See N64KR at http://KRBuilder.org - Then click on the pics 
See you at the 2010 - KR Gathering in Richmond, Ky - I39
There is a time for building and a time for FLYING and the time for Flying
has begun.
Daniel R. Heath - Lexington, SC


-Original Message-
From: krnet-boun...@mylist.net [mailto:krnet-boun...@mylist.net] On Behalf
Of Mark Langford
Sent: Wednesday, September 08, 2010 10:13 AM
To: KRnet
Subject: Re: KR> Weight and balance at the Gathering

I'll also bring some ramps that are perfect for those scales.  I have two of

them, anyway, and they are something like 1.5" thick.  Another of those 
would be nice, along with something like a 24" stool for the tailwheel 
planes, although a cardboard box or two might get that job done.  If anybody

that's driving has one of those it'd be good.

Mark Langford
n5...@hiwaay.net
website www.n56ml.com


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KR> Weight and balance at the Gathering

[Mark Langford]

I'll also bring some ramps that are perfect for those scales.  I have two of 
them, anyway, and they are something like 1.5" thick.  Another of those 
would be nice, along with something like a 24" stool for the tailwheel 
planes, although a cardboard box or two might get that job done.  If anybody 
that's driving has one of those it'd be good.

Mark Langford
n5...@hiwaay.net
website www.n56ml.com

KR> Weight and balance at the Gathering

[erickelshei...@att.net]

  Hope someone makes a video of it just in case I am not there yet. 
Would be great to see but I wont be there till around 5:00 pm on Friday. 

--- On Wed, 9/8/10, Mark Langford <n5...@hiwaay.net> wrote:

From: Mark Langford <n5...@hiwaay.net>
Subject: Re: KR> Weight and balance at the Gathering
To: "KRnet" <kr...@mylist.net>
List-Post: krnet@list.krnet.org
Date: Wednesday, September 8, 2010, 8:53 AM

Another activity that Joe Horton dreamed up is a weight and balance demo. 
He and I both have an identical Pelouze 400 pound scale and if somebody has 
an accurate 300 or 400 pound scale we would have enough for a nosewheel. 
I'm guessing that will happen on Friday, because I think Saturday's schedule 
is pretty full of forums already.

Mark Langford
n5...@hiwaay.net
website www.n56ml.com


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KR> Weight and balance at the Gathering

[Dan Heath]

I have a brand new 400 pound Pelouze, with remote digital readout.  If Jim
does not think it will be a problem putting it in the Cheetah, I will bring
it.  Let you know for sure later today.

See N64KR at http://KRBuilder.org - Then click on the pics 
See you at the 2010 - KR Gathering in Richmond, Ky - I39
There is a time for building and a time for FLYING and the time for Flying
has begun.
Daniel R. Heath - Lexington, SC

-Original Message-
From: krnet-boun...@mylist.net [mailto:krnet-boun...@mylist.net] On Behalf
Of Mark Langford
Sent: Wednesday, September 08, 2010 8:53 AM
To: KRnet
Subject: Re: KR> Weight and balance at the Gathering

Another activity that Joe Horton dreamed up is a weight and balance demo. 
He and I both have an identical Pelouze 400 pound scale and if somebody has 
an accurate 300 or 400 pound scale we would have enough for a nosewheel. 
I'm guessing that will happen on Friday, because I think Saturday's schedule

is pretty full of forums already.

Mark Langford
n5...@hiwaay.net
website www.n56ml.com


___
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please see other KRnet info at http://www.krnet.org/info.html

KR> Weight and balance at the Gathering

[Mark Langford]

Another activity that Joe Horton dreamed up is a weight and balance demo. 
He and I both have an identical Pelouze 400 pound scale and if somebody has 
an accurate 300 or 400 pound scale we would have enough for a nosewheel. 
I'm guessing that will happen on Friday, because I think Saturday's schedule 
is pretty full of forums already.

Mark Langford
n5...@hiwaay.net
website www.n56ml.com

KR> Weight and balance

[ralph h snyder]

Netters
One more weight and balance question.
  Where should the CG be on an empty airplane?  My KR2 plans say the CG 
envelope is 4" ahead of the aft side of the front spar to 4" behind it.By 
moving my battery and ELT as far back in the tail as I can, I come out right at 
the forward CG. When I load it up with pilot, passenger, full fuel in the 
header and wing tanks and 15 lbs. of luggage I only move it back 3.4 ". This is 
still in the front half of the envelope. 
I do not want to use the back 2" of the envelope, but this seems a little far 
forward.
  Where is the normal starting point, and how much does it usually change from 
empty to full?
  I appreciate any help I can get.
  Ralph Snyder
  Burbank, CA
  ralphnd...@sbcglobal.net

KR> Weight and balance

[Barry Kruyssen]

Hi Ralph,

The empty CG is not relevant.  The CG of the plane when loaded is the issue.

If you have a header fuel tank then you want to be right on the forward
limit with minimum pilot weight, no baggage and a full tank of fuel, the CG
will move back as you burn fuel off. 
On the other hand if you have wing tanks then you want to be right on the
forward limit with minimum pilot weight, no baggage and a minimum fuel in
the tank, the CG will move forward as you burn fuel off.  Having the CG as
forward as possible will give you the CG range to be able to take passengers
and baggage without using the last 2" of the CG.

See my weight and balance info at
http://www.users.bigpond.com/kr2/w_and_b.htm

Regards
Barry Kruyssen
Cairns, Australia
k...@bigpond.com
http://www.users.bigpond.com/kr2/kr2.htm


-Original Message-
Netters
One more weight and balance question.
  Where should the CG be on an empty airplane?  My KR2 plans say the CG
envelope is 4" ahead of the aft side of the front spar to 4" behind it.By
moving my battery and ELT as far back in the tail as I can, I come out right
at the forward CG. When I load it up with pilot, passenger, full fuel in the
header and wing tanks and 15 lbs. of luggage I only move it back 3.4 ". This
is still in the front half of the envelope. 
I do not want to use the back 2" of the envelope, but this seems a little
far forward.
  Where is the normal starting point, and how much does it usually change
from empty to full?
  I appreciate any help I can get.
  Ralph Snyder
  Burbank, CA
  ralphnd...@sbcglobal.net

KR> Weight and balance

[Brian Kraut]

I checked my spreadsheet and mine was at 44.36" when empty.  That is about 1
and a quarter inches in front of the forward C.G. range.  I'll send you my
spreadsheet directly.

Brian Kraut
Engineering Alternatives, Inc.
www.engalt.com

-Original Message-
From: krnet-bounces+brian.kraut=engalt@mylist.net
[mailto:krnet-bounces+brian.kraut=engalt@mylist.net]On Behalf Of
ralph h snyder
Sent: Tuesday, September 12, 2006 2:54 AM
To: KRnet
Subject: KR> Weight and balance


Netters
One more weight and balance question.
  Where should the CG be on an empty airplane?  My KR2 plans say the CG
envelope is 4" ahead of the aft side of the front spar to 4" behind it.By
moving my battery and ELT as far back in the tail as I can, I come out right
at the forward CG. When I load it up with pilot, passenger, full fuel in the
header and wing tanks and 15 lbs. of luggage I only move it back 3.4 ". This
is still in the front half of the envelope.
I do not want to use the back 2" of the envelope, but this seems a little
far forward.
  Where is the normal starting point, and how much does it usually change
from empty to full?
  I appreciate any help I can get.
  Ralph Snyder
  Burbank, CA
  ralphnd...@sbcglobal.net
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KR> weight and balance standard KR2 tri gear

[jeffyor...@qx.net]

OK, I have lost my paperwork on figuring the weight and balance for my standard 
KR2 tri gear. What paperwork I can find, I can not figure out my own notes and 
its important enough that I do not want to be guessing. With all this CG talk 
lately and the fact that I have made a few changes over the last few months.

I re weighed my plane but i can not remember what my moment is or how to figure 
the WB and CG. Everything I find seems to be for figuring it on a tail drag KR.

What I have is 252 lbs on each main and 180 on the nose, no fuel but 3 qts of 
oil in my Vw2180.

Can anybody out there help out a suddenly brain dead?

Jeff York
Lexington, KY.

KR> weight and balance standard KR2 tri gear

[D F Lively]

Jeff:

I do not think much would change as far as the CG range is concerned as it must 
still fall within the range appropriate for your airfoil for that will not have 
changed.  The stall speed should not have changed either beyond changes 
dictated by gross weight unless the wing has been changed.  Your plane should 
still
be the same unless your changes have moved it outside the CG envelope.

Don
  

"jeffyor...@qx.net" wrote:

> OK, I have lost my paperwork on figuring the weight and balance for my 
> standard KR2 tri gear. What paperwork I can find, I can not figure out my own 
> notes and its important enough that I do not want to be guessing. With all 
> this CG talk lately and the fact that I have made a few changes over the last 
> few months.
>
> I re weighed my plane but i can not remember what my moment is or how to 
> figure the WB and CG. Everything I find seems to be for figuring it on a tail 
> drag KR.
>
> What I have is 252 lbs on each main and 180 on the nose, no fuel but 3 qts of 
> oil in my Vw2180.
>
> Can anybody out there help out a suddenly brain dead?
>
> Jeff York
> Lexington, KY.
> ___
> Search the KRnet Archives at http://www.maddyhome.com/krsrch/index.jsp
> to UNsubscribe from KRnet, send a message to krnet-le...@mylist.net
> please see other KRnet info at http://www.krnet.org/info.html

KR> weight and balance standard KR2 tri gear

[M & C]

Jeff, that's easy you need a datum line and dist from datum line to front 
axle also dist from datum to  main axles. datum can be anywhere you choose. 
I would suggest you put it 60 inches in frount of front axle. Thus keeping 
all moments + and all dimentions in inches. Multiply dist fromp datum to 
each axle times weights. "example 60 inches times 180 lbs (front axle) gives 
you a moment of 10,800 pound inches. Now do the mains, add all moments and 
divide by total weight of aircraft to get cg location in inches from the 
established datum. Post your info and the net can check your calcs.

Mike Turner
Jackson Missouri

- Original Message - 
From: <jeffyor...@qx.net>
To: <kr...@mylist.net>
Sent: Sunday, April 16, 2006 8:47 PM
Subject: RE : KR> weight and balance standard KR2 tri gear


>
>
>
> OK, I have lost my paperwork on figuring the weight and balance for my 
> standard KR2 tri gear. What paperwork I can find, I can not figure out my 
> own notes and its important enough that I do not want to be guessing. With 
> all this CG talk lately and the fact that I have made a few changes over 
> the last few months.
>
> I re weighed my plane but i can not remember what my moment is or how to 
> figure the WB and CG. Everything I find seems to be for figuring it on a 
> tail drag KR.
>
> What I have is 252 lbs on each main and 180 on the nose, no fuel but 3 qts 
> of oil in my Vw2180.
>
> Can anybody out there help out a suddenly brain dead?
>
> Jeff York
> Lexington, KY.
> ___
> Search the KRnet Archives at http://www.maddyhome.com/krsrch/index.jsp
> to UNsubscribe from KRnet, send a message to krnet-le...@mylist.net
> please see other KRnet info at http://www.krnet.org/info.html 

KR> Weight and Balance

[JIM VANCE]

I have a standard conventional geared KR-2 powered by a 1915 cc GP VW with a 
rear drive.  I have the battery mounted on the firewall at this time.

I'm ready to weigh it, and would like to have it close to the right c of g 
before I rent the scales.  Right now, when I bring the tail up to flight 
attitude, I have almost no weight on the tail.  Is this an indication that it 
is nose heavy?  Should I move the battery to behind the seats before I bother 
with weighing?

I would appreciate input from those who have gone before.

Thanks.

Jim Vance
va...@claflinwildcats.com

KR> Weight and Balance

[Dan Heath]

Jim,

What kind of conventional gear are you using?  Do you have the wings on it?
If I remember correctly, there is only about 12# on the tail.  If your gear
is at the wrong angle, this will also cause you to fall over on the nose.

I say do the preliminary W before making any changes, because, otherwise,
you will just be guessing. 

See N64KR at http://KR-Builder.org - Then click on the pics 
There is a time for building and a time for FLYING and the time for building
has expired.
Daniel R. Heath - Columbia, SC
See you in Mt. Vernon - 2005 - KR Gathering

You wrote:

  Should I move the battery to behind the seats before I bother with
weighing?

Réf. : KR> Weight and Balance

[Serge VIDAL]

If it can reassure you, mine has only 1.6 kg on the tail.

Once you step on board, the picture becomes quite different.

Keep your battery where it is.

Serge Vidal
KR2 ZS-WEC
Paris, France





"JIM VANCE" <va...@claflinwildcats.com>

Envoyé par : krnet-boun...@mylist.net
2004-12-13 12:04
Veuillez répondre à KRnet
Remis le : 2004-12-13 11:58


Pour :  "krnet" <kr...@mylist.net>
cc :(ccc : Serge VIDAL/DNSA/SAGEM)
    Objet : KR> Weight and Balance



I have a standard conventional geared KR-2 powered by a 1915 cc GP VW with 
a rear drive.  I have the battery mounted on the firewall at this time.

I'm ready to weigh it, and would like to have it close to the right c of g 
before I rent the scales.  Right now, when I bring the tail up to flight 
attitude, I have almost no weight on the tail.  Is this an indication that 
it is nose heavy?  Should I move the battery to behind the seats before I 
bother with weighing?

I would appreciate input from those who have gone before.

Thanks.

Jim Vance
va...@claflinwildcats.com
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KR> Weight and Balance

[Stephen Jacobs]

I say do the preliminary W before making any changes, because,
otherwise,
you will just be guessing.

+

You can always get some idea of the CG location by seeing where it
actually balances.

Don't poke any holes in the bottom wing skins, but gently resting it on
two trestles will give you a good indication.  Make sure there is a
spar, ply rib or something where it rests.  Some scrap foam will help
here.

Not sure I want a battery anywhere behind me - just in case there is a
sudden stop.

Steve J

KR> Weight and Balance

[patrusso]

On the three KR's that I have worked on they had 5, 7 and 9 lbs on the tail
wheel and the CG was still comfortably within design range. Your completed
weight and balance figures will supply you with the info you seek.
- Original Message -
From: "JIM VANCE" <va...@claflinwildcats.com>
To: "krnet" <kr...@mylist.net>
Sent: Monday, December 13, 2004 6:04 AM
Subject: KR> Weight and Balance


> I have a standard conventional geared KR-2 powered by a 1915 cc GP VW with
a rear drive.  I have the battery mounted on the firewall at this time.
>
> I'm ready to weigh it, and would like to have it close to the right c of g
before I rent the scales.  Right now, when I bring the tail up to flight
attitude, I have almost no weight on the tail.  Is this an indication that
it is nose heavy?  Should I move the battery to behind the seats before I
bother with weighing?
>
> I would appreciate input from those who have gone before.
>
> Thanks.
>
> Jim Vance
> va...@claflinwildcats.com
> ___
> Search the KRnet Archives at http://www.maddyhome.com/krsrch/index.jsp
> to UNsubscribe from KRnet, send a message to krnet-le...@mylist.net
>
> please see other KRnet info at http://www.krnet.org/info.html

KR> Weight and Balance

[The Weber's]

On Ken Rand's original KR-2 He had minus 1/2 pound when the tail was up in
the flying position.  So your plane should be good.
- Original Message - 
From: "JIM VANCE" <va...@claflinwildcats.com>
To: "krnet" <kr...@mylist.net>
Sent: Monday, December 13, 2004 5:04 AM
Subject: KR> Weight and Balance


> I have a standard conventional geared KR-2 powered by a 1915 cc GP VW with
a rear drive.  I have the battery mounted on the firewall at this time.
>
> I'm ready to weigh it, and would like to have it close to the right c of g
before I rent the scales.  Right now, when I bring the tail up to flight
attitude, I have almost no weight on the tail.  Is this an indication that
it is nose heavy?  Should I move the battery to behind the seats before I
bother with weighing?
>
> I would appreciate input from those who have gone before.
>
> Thanks.
>
> Jim Vance
> va...@claflinwildcats.com
> ___
> Search the KRnet Archives at http://www.maddyhome.com/krsrch/index.jsp
> to UNsubscribe from KRnet, send a message to krnet-le...@mylist.net
>
> please see other KRnet info at http://www.krnet.org/info.html
>

KR> Weight and Balance

[Barry Kruyssen]

Hi Jim,

Before getting certified scales I've done a weights and balances using 3 bath 
room scales.

Step 1: Calibrate the scales by getting a known weight and recording what the 
scales read with known weights.
I used 4 plastic drums each with 20kg in them to record the weights 
for 20, 40, 60 and 80 kg for each scale.

Step 2: Get the plan level in the flying attitude and weigh the aircraft (I 
weighed it empty and with me in it so a got a semi accurate pilots arm length)

Step 3: Repeat step 2 twice more switching the scales around to confirm/average 
your readings.

Setp 4: Using the readings for each wheel, correct values using the 
calibrations, average them out and use the average values to calculate your C 
of G.

Using the above method I got 0.2kg variance between scales when weighed on each 
wheel.

SPECIAL NOTE: I made timber blocks with chocks to sit on the scales to ensure 
the load was central and always in the same place.

I haven't yet confirmed my C of G with certified scales, I hope to do this soon.

Regards
Barry Kruyssen
Cairns, Australia
RAA 19-3873 

k...@bigpond.com
http://users.tpg.com.au/barryk/KR2.htm 



  - Original Message - 
  From: JIM VANCE 
  To: krnet 
  Sent: Monday, December 13, 2004 9:04 PM
  Subject: KR> Weight and Balance


  I have a standard conventional geared KR-2 powered by a 1915 cc GP VW with a 
rear drive.  I have the battery mounted on the firewall at this time.

  I'm ready to weigh it, and would like to have it close to the right c of g 
before I rent the scales.  Right now, when I bring the tail up to flight 
attitude, I have almost no weight on the tail.  Is this an indication that it 
is nose heavy?  Should I move the battery to behind the seats before I bother 
with weighing?

  I would appreciate input from those who have gone before.

  Thanks.

  Jim Vance
  va...@claflinwildcats.com
  ___
  Search the KRnet Archives at http://www.maddyhome.com/krsrch/index.jsp
  to UNsubscribe from KRnet, send a message to krnet-le...@mylist.net

  please see other KRnet info at http://www.krnet.org/info.html

KR> Weight and Balance

[eclarse...@aol.com]

In a message dated 12/13/2004 8:45:23 AM Eastern Standard Time, 
va...@claflinwildcats.com writes:
before I rent the scales. 
Jim,
 Before you rent scales, check at the local auto parts/speed shops and find a 
guy that drives circle track, most likely he has a nice digital set and would 
be more than happy to see your project and give you a hand. Might require 
looking at his toy too.
Cheers,
 Ed Larsen
 Ypsi, MI

KR> Weight and Balance

[francis fenlason]

-Original Message-
From: krnet-boun...@mylist.net [mailto:krnet-boun...@mylist.net] On
Behalf Of Barry Kruyssen
Sent: Monday, December 13, 2004 4:56 PM
To: KRnet
Subject: Re: KR> Weight and Balance

Hi Jim,

Before getting certified scales I've done a weights and balances using 3
bath room scales.>>>

If you are using bathroom scale, use something to reinforce the top of
the scale. I didn't and I had to but another scale. Other wise I did as
you suggested and felt I came out well at the stage I'm at.  Also be
careful when you bring the plane to flight attitude, if you drop it, it
may fall on its nose.  Russ  Breckenridge

KR> Weight and Balance

[Dan Heath]

Our chapter has made up two sets of two bathroom scales each attached under
a support platform and you use your personal bathroom scale for the tail.
That way, you are not trying to measure at the top end of the scale as each
one will only be carrying around 150 pounds. 



See N64KR at http://KR-Builder.org - Then click on the pics 

There is a time for building and a time for FLYING and the time for building
has expired.

Daniel R. Heath - Columbia, SC

See you in Mt. Vernon - 2005 - KR Gathering

KR> Weight and Balance

[ronev...@cox.net]

Netters;
  After one has "done the math", and you think you have the weight and 
balance close, apply a practical test to the situation.  Taxi on to a long 
runway.  Power up and go roaring down the runway.  Gently apply forward 
pressure on the stick in order to get the tail up.  Once the tail is up, apply 
gentle back pressure until you get the mains off.  Fly about 5 feet above the 
runway for a short distance and make a subjective judgement concerning the 
correctness of your balance.  If you can fly comfortably in ground effect, you 
will probably be OK to fly your KR out of ground effect.  You may want to do 
this several times before you commit yourself to a trip "around the patch".  
Caution is the key.  Don't rush into flight after having spent several years 
building another great KR!

RV

KR> Weight and Balance

[Orma]

Hello Dan and Net.
A similar scale trick can be done with one bath scale and a two foot board 
of sufficient strength, Such as a 2X6.  On one end of the 2X6 needs an end 
board attached equal in height to the top of the scale, and the other end 
sits on the scale.  The wheel sits at the half way point of the board.  The 
scale will read 1/2 of the actual weight.
In my opinion for no reason should you attempt lift off prior to determining 
the weight and balance of the aircraft with a bathroom scale or  a certified 
aircraft scale.  If you take off without a weight test you may find your 
nose too high, too fast and damage your craft.  The KR is much too quick an 
aircraft to experiment with unless you are very familiar with it.  Always be 
completely ready to fly when you go onto the runway even if only for HS taxi 
testing.
Orma
Southfield, MI
N110LR celebrating 20 years
Flying, flying and more flying
http://www.kr-2.aviation-mechanics.com/ 

KR> Weight and Balance

[Mike Turner]

If you know the location of the mains relative to the leading edge of the of 
the wing you can make this determination.  Let's say the mains are 8" behind 
the leading edge, then they are at the forward limit for the cg envelope. When 
empty and with the tail raised to flight position and the tail weighing nothing 
then your empty weight cg is at the forward limit. When you add weight such as 
pilot/passenger the cg moves back. Fuel, if it's a header tank will move the cg 
back forward so you may be pretty close. 

   Mike Turner 
   Jackson, Mo
  - Original Message - 
  From: The Weber's<mailto:mo...@mhtc.net> 
  To: KRnet<mailto:kr...@mylist.net> 
  Sent: Monday, December 13, 2004 4:38 PM
  Subject: Re: KR> Weight and Balance


  On Ken Rand's original KR-2 He had minus 1/2 pound when the tail was up in
  the flying position.  So your plane should be good.
  - Original Message - 
  From: "JIM VANCE" 
<va...@claflinwildcats.com<mailto:va...@claflinwildcats.com>>
  To: "krnet" <kr...@mylist.net<mailto:kr...@mylist.net>>
  Sent: Monday, December 13, 2004 5:04 AM
  Subject: KR> Weight and Balance


  > I have a standard conventional geared KR-2 powered by a 1915 cc GP VW with
  a rear drive.  I have the battery mounted on the firewall at this time.
  >
  > I'm ready to weigh it, and would like to have it close to the right c of g
  before I rent the scales.  Right now, when I bring the tail up to flight
  attitude, I have almost no weight on the tail.  Is this an indication that
  it is nose heavy?  Should I move the battery to behind the seats before I
  bother with weighing?
  >
  > I would appreciate input from those who have gone before.
  >
  > Thanks.
  >
  > Jim Vance
  > va...@claflinwildcats.com<mailto:va...@claflinwildcats.com>
  > ___
  > Search the KRnet Archives at 
http://www.maddyhome.com/krsrch/index.jsp<http://www.maddyhome.com/krsrch/index.jsp>
  > to UNsubscribe from KRnet, send a message to 
krnet-le...@mylist.net<mailto:krnet-le...@mylist.net>
  >
  > please see other KRnet info at 
http://www.krnet.org/info.html<http://www.krnet.org/info.html>
  >


  ___
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KR> Weight and Balance

[paulw...@webtv.net]

Hi, all;
Has anybody tried successfully to do the  W/B with ONE accurate bathroom
scale? That is...weighing right, left and tail independantly after
leveling the aircraft? Can it be done this way? 

Just wondering about it.

Still looking for single port intake manifolds for KR.

Paul
KR2s, primed, doing baffles

KR> Weight and Balance

[Mark Jones]

Paul,
This is an acceptable method. However, you must make sure to block the main
wheel and nose wheel if you have one, that is not on a scale, to the same
height as the scale.

Mark Jones (N886MJ)
Wales, WI

-Original Message-
From: krnet-boun...@mylist.net [mailto:krnet-boun...@mylist.net]On
Behalf Of paulw...@webtv.net
Sent: Wednesday, December 15, 2004 8:05 AM
To: kr...@mylist.net
Subject: RE: KR> Weight and Balance


Hi, all;
Has anybody tried successfully to do the  W/B with ONE accurate bathroom
scale? That is...weighing right, left and tail independantly after
leveling the aircraft? Can it be done this way? 

J

KR> Weight and Balance

[larry flesner]

>Has anybody tried successfully to do the  W/B with ONE accurate bathroom
>scale? That is...weighing right, left and tail independantly after
>leveling the aircraft? Can it be done this way? 
>Paul
++

Yes,  that will work justs fine providing you get the airplane releveled
exactly each time.  You will need to build some sort of pad to 
elevate the other main wheel to the same height as the scale.
You should get exactly the same results, just a lot more hassle.

Larry Flesner

KR> Weight and Balance

[larry severson]

I used a commercial shipping scale from Office Depot one wheel at a time, 
but I did put the other wheels on blocks at the appropriate heights. I got 
very accurate numbers which matched the expensive airplane scale results.
Has anybody tried successfully to do the  W/B with ONE accurate bathroom
>scale? That is...weighing right, left and tail independantly after
>leveling the aircraft? Can it be done this way?

Larry Severson
Fountain Valley, CA 92708
(714) 968-9852
lar...@socal.rr.com 

KR> Weight and Balance

[Randy Smith]

Buy one more scale. it will be a hole lot easer. The tail will be somewhere 
between -5 and +5. so you don't need much back there.
- Original Message - 
From: <paulw...@webtv.net>
To: "KRnet" <kr...@mylist.net>
Sent: Wednesday, December 15, 2004 8:04 AM
Subject: RE: KR> Weight and Balance


> Hi, all;
> Has anybody tried successfully to do the  W/B with ONE accurate bathroom
> scale? That is...weighing right, left and tail independantly after
> leveling the aircraft? Can it be done this way?
>
> Just wondering about it.
>
> Still looking for single port intake manifolds for KR.
>
> Paul
> KR2s, primed, doing baffles
>
>
> ___
> Search the KRnet Archives at http://www.maddyhome.com/krsrch/index.jsp
> to UNsubscribe from KRnet, send a message to krnet-le...@mylist.net
>
> please see other KRnet info at http://www.krnet.org/info.html
> 

KR> Weight and Balance

[raybeth...@sbcglobal.net]

If Randy Snith, the author of this E-mail, is the Randy Smith of Denton, 
Texas,
please reply to me Ray Goree of Arlington, Texas. I would like to talk with 
you.
raybeth...@sbcglobal.net 817-795-4779 

KR> Weight and Balance

[JIM VANCE]

Those builders who have shared their weights and balances with the group 
usually have the main gear within a few pounds of each other.

Since the KR-2 will be flown solo most of the time, shouldn't the heavy items, 
such as the battery and ELT, be placed on the right side to partially 
compensate for the weight of the pilot on the left side?  Comments and 
thoughts, please.

Jim Vance
va...@claflinwildcats.com

KR> Weight and Balance

[Dan Heath]

That is what we are doing. ELT and Battery are on Pass side. 



"There is a time for building and a time for GOING TO THE GATHERING, and the
time for building has long since expired."

See you in Mt. Vernon - 2004 - KR Gathering http://KRGathering.org

See N64KR at http://KR-Builder.org - Then click on the pics

Daniel R. Heath - Columbia, SC

KR> Weight and Balance

[Ray Goree]

Sounds reasonable to me. Thanks for the suggestion. I'll probably do my 2S that 
way.  
Ray goree

JIM VANCE  wrote:
Those builders who have shared their weights and balances with the group 
usually have the main gear within a few pounds of each other.

Since the KR-2 will be flown solo most of the time, shouldn't the heavy items, 
such as the battery and ELT, be placed on the right side to partially 
compensate for the weight of the pilot on the left side? Comments and thoughts, 
please.

Jim Vance
va...@claflinwildcats.com
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KR>Weight and Balance

[Phillip Matheson]

Hi all
I found this site about weight and balance sofewere

http://www.lockmanenterprises.com/about_us.html


Phillip Matheson
mathe...@dodo.com.au
Australia
VH PKR
See our engines  and kits at.
http://www.vw-engines.com/
http://www.homebuilt-aviation.com/
See my KR at Mark Jones web
http://mywebpage.netscape.com/n886mj/pmkr2.html

KR>weight and balance

[larry flesner]

>I'm going to make a set brackets the bolt to the WAF so I can lift the
plane off the ground, so I can play with the w the same as model
aircraft. I visited the Cobra aircraft factory some time back, and they had
their Cobra hanging from the roof on Cof G brackets, and modifying the
engine mounts to adjust the W worked great. So you can move everthing
around and really see what it does to the actual balance of the aircraft.
>Phil Matheson
++

Phil,

If you use a good set of scales to weigh the aircraft and get an
accurate measurement to different points on the aircraft, you
can do the same thing with a pencil and paper in the comfort
of your home. :-)

Larry Flesner