KR> Fuselage dimensions for N729PK

[Pete Klapp]

Joe
I used all 14' of the longeron material from Wicks as suggested by Mark 
Langford. Mine measures 28" (2'4") to the front face of the firewall from the 
front face of the fwd spar. From the front face of the fwd spar to the aft face 
of the bottom of the stern post, I measured 141" (11'-9"). I added an addition 
bay to the fuselage. My fuselage is 4" wider than a std KR-2S. Of the 
additional length, 3" of it was added forward of the front spar, the rest is 
aft.
Pete Klapp

KR> Fuselage dimensions and shape

[Mark Langford]

"Duncan of Devonport" wrote:

> I know this question has been asked already, but I'm still uncertain about
> this...  Basically, I have three questions:

You're right, this has been answered several times, but I can see how
searching the archives for it might be tedious.  And since nobody else has
bitten, I'll give it a shot.

> I have a set of KR2-S plans, which as we know has an extra bay added to
the
> KR2 plans (ie lengthened by 14" aft of the cabin).  Based on best practice
> as evolved here on KRNet, by how much (in addition to this) should I
> lengthen each bay aft of the cabin?  And do I lengthen the bays forward of
> the firewall?

The politically correct reply would be to "consult an engineer", but since
there's no documented problem with KR tails separating in flight (hurricanes
don't count), I'd think you could get away with adding an inch and a half to
each bay and not substantially change the geometry of the structure.  One
consideration that somebody pointed out is that the scarf joint for the
plywood skin needs to fall on a wooden member, so keep that in mind, or
simply add one more bay instead.  Either way, you'll probably need more
plywood, but in my eperience, you'll need more plywood than the plans call
for anyway, so go ahead and buy another sheet while you're getting the rest.
I wouldn't lengthen the fuselage in front of the spar more than two inches,
unless you're going to put a light engine in it.

> If I widen the cabin to 40", this will effectively reduce the area of the
> wings, since the cockpit is now encroaching on the wing root by a few
> inches on each side.  Do I lengthen the spars/wings by the same amount to
> compensate for this encroachment?

I wouldn't bother, considering the slight width change that you're talking
about.  "Wing area" typically includes the area of the fuselage between the
wings anyway.

> Finally, question 3
> If I widen the cockpit to (say) 40" at the top, by how much should I widen
> the bottom of the cockpit?  By an equal amount?  And a supplementary
> question...  Is there any fundamental or aesthetic reason why the cockpit
> should be wider at the top than at the bottom?  Could the sides not be
> perpendicular?

You can either widen the bottom the same amount as you widened the top, or
you can make the sides perpendicular to the bottom.  Your choice.  You
wouldn't be the first to make the sides vertical.  Any detrimental aero
tradeoffs would be minor, and it would be somewhat easier to build.

There's more of this kind of stuff located at
http://home.hiwaay.net/~langford/kopinion.html .

Mark Langford, Huntsville, AL
N56ML at hiwaay.net
see KR2S project N56ML at http://home.hiwaay.net/~langford

KR> Fuselage dimensions and shape

[VIRGIL N SALISBURY]

It is a much simpler build to make the sides straight than taper
top to bottom, Virg

On Sun, 15 Aug 2004 22:17:00 -0400 (Eastern Standard Time) "Dan Heath"
 writes:
> RE: Is there any fundamental or aesthetic reason why the cockpit 
> should be
> wider at the top than at the bottom? 
> 
> 
> 
> If your butt is the same width as your shoulders, then why not make 
> it
> streight? However, I don't think it would look as good and would 
> also cause
> it to have more frontal area. If I were making it wider, I would 
> maintain
> the same proportions. 
> 
> I am not building an S, but I don't think the wider fuselage will 
> require
> longer wings.
> 
> Your results will vary!
> 
> "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
> 
>  
> 
>  
> 
> 
> ___
> to UNsubscribe from KRnet, send a message to krnet-le...@mylist.net
> please see other KRnet info at http://www.krnet.org/info.html
> 
> 


Virgil N. Salisbury - AMSOIL
www.lubedealer.com/salisbury
Miami ,Fl

KR> Fuselage dimensions and shape

[Duncan of Devonport]

Hi there,
I know this question has been asked already, but I'm still uncertain about 
this...  Basically, I have three questions:

Question 1
I have a set of KR2-S plans, which as we know has an extra bay added to the 
KR2 plans (ie lengthened by 14" aft of the cabin).  Based on best practice 
as evolved here on KRNet, by how much (in addition to this) should I 
lengthen each bay aft of the cabin?  And do I lengthen the bays forward of 
the firewall?

Question 2
If I widen the cabin to 40", this will effectively reduce the area of the 
wings, since the cockpit is now encroaching on the wing root by a few 
inches on each side.  Do I lengthen the spars/wings by the same amount to 
compensate for this encroachment?

Finally, question 3
If I widen the cockpit to (say) 40" at the top, by how much should I widen 
the bottom of the cockpit?  By an equal amount?  And a supplementary 
question...  Is there any fundamental or aesthetic reason why the cockpit 
should be wider at the top than at the bottom?  Could the sides not be 
perpendicular?

Kind regards
Duncan of Devonport
KR2-S #9792, #1184
Auckland, New Zealand

KR> Fuselage dimensions and shape

[Dan Heath]

RE: Is there any fundamental or aesthetic reason why the cockpit should be
wider at the top than at the bottom? 



If your butt is the same width as your shoulders, then why not make it
streight? However, I don't think it would look as good and would also cause
it to have more frontal area. If I were making it wider, I would maintain
the same proportions. 

I am not building an S, but I don't think the wider fuselage will require
longer wings.

Your results will vary!

"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