KR> Wing Tanks

[Larry Flesner]

At 08:37 PM 10/3/2010, you wrote:
>   Gonna also do a water leak test
>before I put the top on the tank
++

a water leak will only show the worst possible leaks.  Gas will pass 
through a pin hole that will hold water.

Larry Flesner

KR> aerodynamics

[MICHAEL SYLVESTER]

Thanks Guys, I was hoping the speed difference would be minimal. This will save 
some building time as I have the plane upside down doing the cosmetics. Full 
speed ahead.
Mike Sylvester 
kr2s builder 
Birmingham,AL.

Cell no.205-966-3854

KR> Progress

[rkp...@comcast.net]

Hi Everyone 

  Just  a little progress report on my project. I'm getting ready install the 
aft deck.I spent a week finishing all the wiring for nav.lights,strobe 
light,and the trim servo.This week end I installed the comm.antenna,xponder 
antenna and the static vents. 

  Robert Pesak 

  Hermitage, Tn. 

http://photobucket.com/robertskrs

KR> Wing Tanks

[Dan Heath]

Thanks, it is part of the assembly plan.  Gonna also do a water leak test
before I put the top on the tank, then after it is completely together, do
the balloon test.

See N64KR at http://KRBuilder.org - Then click on the pics 
See you at the 2011 - KR Gathering in Mt. Vernon, Il - MVN
There is a time for building and it never seems to end.
Daniel R. Heath - Lexington, SC


-Original Message-
Suggest you add a pressure test to you to do list

KR> Speed Brake - aerodynamics

[Dan Heath]

Nothing that I can tell.  It is just easier to land, and is a little
heavier.

See N64KR at http://KRBuilder.org - Then click on the pics 
See you at the 2011 - KR Gathering in Mt. Vernon, Il - MVN
There is a time for building and it never seems to end.
Daniel R. Heath - Lexington, SC

-Original Message-

Could you tell if the plane was any slower with the brake at full retraction

KR> Prince 52 x 54

[laser...@juno.com]

I've got a recently refinished and immaculate black Prince P-tip for sale
for $850.  I paid over $1200 with a four month wait and spent another
$347 to repair leading edge abrasion from rain.  These props do not hold
up in rain.  Neither do Catto props or any of the composite props I know
of.  One needs to use prop tape to protect the leading edges and this
causes degradation in performance (according to Paul Lipps).   

This prop is newly returned from the factory and has no blemish, scratch,
nick, or any imperfection.  It's exactly like new only without the four
month wait.  If the serial number on it wasn't the same I would think
Lonnie had just sent me another prop.  Comparing it with my Sterba 52 x
52, I've found the 52 x 54 Prince to be perfect for cross country flying
(unless you run into rain).  It has the 6-bolt pattern for the GP2180
Force One hub.  

Lonnie says he installed new and improved leading edge protection but I'm
just going to go back to my Sterba until I get a new prop of custom
design and urethane leading edges. 

Pictures on request.

Email me at laser...@juno.com if interested.  

Thanks, 

Mike
KSEE


$100 Gift card for $6.40
BREAKING NEWS: High Ticket items are being auctioned for an incredible
http://thirdpartyoffers.juno.com/TGL3141/4ca92867bb18621f12m04vuc

KR> aerodynamics / speed brake

[Larry Flesner]

>  This is to the guys that have added a speed brake (Belly Board) 
> after having already flown without one. Could you tell if the plane 
> was any slower with the brake at full retraction ?Jones.
>Mike Sylvester
+++

There is no need for the brake to be thicker than 1/4 inch so fairing 
it in should not be a major task.  If the board retracts flat against 
the bottom of the fuselage and is faired in,  I don't think you would 
notice any difference in speed as we have no way of measuring that 
accurately.  I'm guessing most of us flying can't tell the difference 
between 149 and 150 mph on our ASI. :-)  There are some things that 
we can do to make a noticeable difference and others are just 
"nits".  This one is a "nit" in my opinion.

Larry Flesner

KR> aerodynamics

[MICHAEL SYLVESTER]

Hey Guys, This is to the guys that have added a speed brake (Belly Board) after 
having already flown without one. Could you tell if the plane was any slower 
with the brake at full retraction ? I do not plan on fairing it in unless there 
is a substantial speed difference. As far as the design, I basically copied Dan 
Heath and Mark Jones.   
 Mike Sylvester 
kr2s builder 
Birmingham,AL.

Cell no.205-966-3854

KR> WAF

[Larry Flesner]

>
>Has anyone used wing pins to attach the wings ?
>Eric,
>South Africa.
_)))


I'm not sure you could get the pin tight enough to eliminate any 
movement in the fitting which, over time, would erode the fitting and 
/ or the pin.

I hope this discussion has not caused any concern among those still 
building.  The use of multiple bolts in single sheer on the WAF are 
quite sufficient for safety as proven by the thousands of flight 
hours on that system.  Granted, the single bolt in double sheer is a 
stronger system but not necessary for safety in our application.  I'm 
sure that some governments have required that design as it is very 
easily accomplished with little or no weight gain.  On the other hand 
I know of no one using 1/4 inch cables in the control system just 
because they are stronger.  Adequate is adequate.  If something has 
been flight tested and is safe, go with it.

Larry Flesner

KR> Wing Tanks

[R. Human]

Suggest you add a pressure test to you to do list


Rick Human
N202RH
Houston, Tx



-Original Message-
From: krnet-boun...@mylist.net [mailto:krnet-boun...@mylist.net] On Behalf
Of Dan Heath
Sent: Sunday, October 03, 2010 6:27 PM
To: 'KRnet'
Subject: KR> Wing Tanks


Still to go, build the part that will align the filler cap with the wing
skin, offsetting the angle of the tank, install the fuel probes which are
due to arrive on Tuesday, assemble the tank, patch the holes in the wing,
make the removable panel, install the tank and plumb it all to the existing
fuel fitting in the cabin.  Maybe I will have it ready for the next
Gathering.

KR> Wing Tanks

[Dan Heath]

All attach fittings are complete and the fuel tester drain has been
installed.  Sorry, no pics.  My battery ran out and I did not bring the
refill.  



Still to go, build the part that will align the filler cap with the wing
skin, offsetting the angle of the tank, install the fuel probes which are
due to arrive on Tuesday, assemble the tank, patch the holes in the wing,
make the removable panel, install the tank and plumb it all to the existing
fuel fitting in the cabin.  Maybe I will have it ready for the next
Gathering.



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

See you at the 2011 - KR Gathering in Mt. Vernon, Il - MVN

There is a time for building and it never seems to end.

Daniel R. Heath - Lexington, SC

KR> WAF spacers

[Robin Macdonald]

I agree with you the spacer & one single bolt is stronger than the two 
bolts.

The only problem is to start with this when you fit the WAFs to the spars, 
if the WAFs are slightly out of alignment you have a hellve job to get the 
bolt in without damaging the bolt or the WAF's .  As there has never been a 
problem with the original set up why go looking for trouble.

I have this problem my KR was built in the early 80's & had the single bolt. 
When I removed the bolt I was a bit shocked at the condition of the bolt, 
the bolt needed to be incouraged to go in the hole, I think someone had used 
a hammer.   The WAF's are slightly out of alignment I feel there was too 
much stress on the WAF & the spar to get the bolt through both WAF's. Both 
front & back spars are the same. I want to go back to the multi bolts 
system, I will feel better with good bolts & no stress raisers.

As Mark says make sure the thread of the bolt is out of the sheer load on 
the WAF.


Robin.

NZ. 

KR> WAF

[Eric Evezard]

Hi Netters,
Has anyone used wing pins to attach the wings ?My sailplane has wing pins with 
small handles and thumb push buttons one end with ball bearings at the 
other.One simply presses the thumb button,the ball bearings retract,and the pin 
slides through the WAFs,Let go and it is locked.It takes no time at all.Most 
netters will know all about these pins.I am using the plans bolts and nuts 
system on my KR 2s,as I do not intend rigging and de rigging my KR as I would 
my glider.(outlandings and retrieval etc )However should the necessity ever 
arise (hangarage etc) I would consider wing pins.
Best Regards,
Eric,
South Africa.

KR> WAF spacers

[Mark Langford]

Perhaps I should point out that the main reason I did the single bolt thing 
was so I could eliminate that unsightly at the WAFs and not have to access 
the nuts, although it is also the optimal way to do it (not that the single 
shear method hasn't worked just fine for 100% of the KRs built to date).  I 
just have two small holes in the front of the wing's leading edge that allow 
a longer socket head cap screw to be inserted into the WAF and tightened. 
This sounds great, until you realize that you have no access to the WAFs 
other than those two tiny holes (the rear ones are more easily accessed 
while my split flaps are down).  So getting it all set up properly is akin 
to building a ship in a bottle, and it easily killed a week of my "vacation" 
sorting all of that out.  Although inspection is just about impossible 
without removing the wings, checking WAF torque is a five minute affair.

Yes, I used aluminum spacers.  7075 or 2024 tubing (or bored from a bar) 
would be best, but I used some pretty thick wall 6061-T6.  And I "JB Welded" 
the tubing in between the OUTBOARD WAFs, obviously, not the stub wing WAFs.

I guess I'm going to have to break down and do something about a webpage 
detailing all of that stuff I did on my "summer vacation"...

Mark Langford
N56ML "at" hiwaay.net
website at http://www.N56ML.com
 

KR> WAF spacers/individual bolts

[phillipmathe...@bigpond.com]

I have been around this thing for a long time and this subject keeps coming
up.  I think that the consensus is that the single bolt, with spacer, is the


--
Dan
I use the single bolt, but what I did to make aliment easier was, I 
installed the was in anyway you see fit, then I glued a 5/8 block across the 
bottom of the top WAF, so the wing attachment rests on the block and lines 
up the bolt holes.
Phil Matheson. 

FW: KR> KR2 ARTICLE-KITPLANES NOV 2010

[Patrick and Robin Russo]

Geez, it comes down to this; does one single bolt and spacer weigh less than 
two?!!

> 

KR> WAF spacers/individual bolts

[Dan Heath]

I have been around this thing for a long time and this subject keeps coming
up.  I think that the consensus is that the single bolt, with spacer, is the
way it should be done.  However,  I will bet that there are at least as many
done with a bolt in each attachment as there are with the single bolt and
spacer, and in neither case, has there been a wing failure at the
attachment.  So in practice, it is most likely a mute point.

I use a bolt for each attach point, because getting a single bolt through
both, with a spacer in between, would be an impossible task on my plane,
unless I line bored the holes oversize.  The alignment must be perfect to
start with, or I think you will do more harm than good.  Also, some people
are just better at doing things like that, than are others.

Your results will vary.

See N64KR at http://KRBuilder.org - Then click on the pics 
See you at the 2011 - KR Gathering in Mt. Vernon, Il - MVN
There is a time for building and it never seems to end.
Daniel R. Heath - Lexington, SC

FW: KR> KR2 ARTICLE-KITPLANES NOV 2010

[James Ferris]

Where is all this stuff coming from? I got plans for a KR-1 in the mid 
seventies 
and have never herd of a wing failer on a KR>
Jim



- Original Message 
From: Glenn Martin 
To: KRnet 
Sent: Sat, October 2, 2010 9:49:57 PM
Subject: Re: FW: KR> KR2 ARTICLE-KITPLANES NOV 2010

John Martindale wrote:
> A long time ago before "experimental" came along (like in the 1980s), the
> Australian authorities did mandate a change to the bolt arrangement that
> specified a spacer tube between each pair of WAFs and a longer single
> through bolt instead of two short independent bolts.
>
> I think this reflects a better engineering solution with respect to shear
> forces
I can see how a thicker bolt could improve shear strength, or a bolt of 
a greater rating, but unless I am missing something, I see no way that a 
longer bolt of the same type and size could improve its shear strength 
at the wing attach fitting junction through an increase in its length. 
Did I miss somthing in physics class?

-- 
Glenn Martin (N5PQ)
Martek Mississippi Electronic Repair
13238 Hudson-Krohn Rd.
Biloxi, MS, 39532
rep...@martekmississippi.com


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