From: David de Sosa <d-desosa@raytheon.com>
Subject: COZY: Canard fit problem
Date: Thu, 10 Jun 1999 14:52:31 -0700

Has anyone experienced this scenario?  Canard doesn't fit onto fuselage
mounted pins at all until air temperature warms up above 85% or so.  Then
it fits although very snugly which I assume is how it is supposed to fit.
I do seem to remember originally installing the pins during the warm  
weather months but did not anticipate a problem like this! 

Is there enough of an expansion or contraction rate difference between the
fuselage and the canard section length that fits adjacent to it to cause 
this type of problem.  Has anyone else experienced a problem like this?  I
seem to remember similar issues reported about the Canopy/turtleback 
assembly since it is exposed to a wide variation in temperature at altitude
vs. sea level.


David de Sosa
Cozy MkIV #080

Date: Fri, 11 Jun 1999 06:01:13 -0400
From: Jeff Russell <JRaero@gte.net>
Subject: Re: COZY: Canard fit problem



David de Sosa wrote:

> Has anyone experienced this scenario?  Canard doesn't fit onto fuselage
> mounted pins at all until air temperature warms up above 85% or so.

David, what type of resin system are you using?  Sounds strange :-)

--
Jeff Russell/AeroCad Inc.                    E-mail:   Jeff@aerocad.com
2954 Curtis King Blvd.  Ft. Pierce, FL. 34946
Shop# 561-460-8020 7:00am to 3:30pm  Home# 561-344-6200
Website:   http://www.Aerocad.com
Composite workshop info:   http://www.Sportair.com


From: "cliffordfamily" <cliffordfamily@provide.net>
Subject: Re: COZY: Fuel valve location
Date: Mon, 14 Jun 1999 03:40:06 -0400

someone questioned about the canard fit and I lost your address.  Your
question was about temperature and fit.   I have not yet gotten to the
canard chapter, but will share with you what I know about composit material.
Some years ago I built checking fixtures for automobile parts out of metal.
Most often the models were made of composites.  When the metal checking
fixture was built and tuned to the required tolerances of plus or minus
1&1/2 thousands,(.0015), of an inch, it was expected that those tolerances
would change as the temp varied.  The composit model would expand with a
temp increase and contract somewhat when cooler.  This would make our go/no
go of .003 almost impossible  to maintain in a uncontroled temperature
enviroment.  The engineers always kpt that into consideration when checking
for tolerances.  Composits WILL expand and contract somewhat with
temperature changes. My only thoughts are that your tolerances for clearance
are too close.

Dave & Mike

From: "guy Terren" <guy.terren@laposte.fr>
Subject: COZY: canard clearance
Date: Thu, 8 Jul 1999 14:46:26 +0200

I'm fixing the canard and i need some details

Do i need a clearance around the canard at the fuse entrance above F22 to allow canard flexion?

Thanks for an answer
Guy
From ???@??? Sat Jul 10 11:40:53 1999
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Date: Fri, 09 Jul 1999 21:17:10 -0400
To: Cozy Builders Mailing List <cozy_builders@canard.com>
From: "Marc J. Zeitlin" <marcz@ultranet.com>
Subject: Fwd: COZY: canard clearance
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guy Terren asks;

>Do i need a clearance around the canard at the fuse entrance above F22 to 
>allow canard flexion?

If I understand the question correctly, the answer is no.  When you attach
the canard to the fuselage in Chapter 12, you do leave a small gap
underneath when shaping the cutout so that the BID layup will have some
space.  There is also some space around the elevator torque tube assembly,
but it's small as well.  There is no other space required or called out for
"flexing" of the canard.
--
Marc J. Zeitlin           mailto:marcz@ultranet.com
                          http://www.ultranet.com/~marcz/

From: "Tonya Davis" <flyboy@creative-net.net>
Subject: Re: COZY: canard clearance
Date: Fri, 9 Jul 1999 21:27:12 -0500



>guy Terren asks;
>Then Marc answered:
>>Do i need a clearance around the canard at the fuse entrance >
>If I understand the question correctly, the answer is no

If I may chip in here:  I believe that technically Marc is correct.  In
practice it may be better to leave a very small gap; say 1/16 of an inch or
so.  When you reinstall the canard (after paint), fill the small gap with
silicone for an air/water tight joint.  When the canard does flex ever so
slightly, it won't chip your paint.

'this is only worth one cent.

Mike
Cozy MkIV N141MD
flying quite well

From: cdenk@ix.netcom.com
Date: Sat, 10 Jul 1999 07:02:18 -0500 (CDT)
Subject: Re: Fwd: COZY: canard clearance

Was said <some space around the elevator torque tube assembly>
Mine is less than 1/8". Part of the tube opening is framed by a piece attached to the fuselage, and part to the canard. I DO 
NOT weatherstrip the elevator tube opening, concern for water freezing the elevator in position as passing into freezing air 
during climb. I do have a small interior rain gutter under the tube opening, but for some reason its not effective. Thats the 
only place water gets in the plane either on the ground or in the air in heavy rain. The most we have seen between the pedals 
and instrument panel is a half cup per side.

Date: Sat, 10 Jul 1999 11:54:13 -0500
From: Bulent Aliev <atlasyts@bellsouth.net>
Subject: Re: Fwd: COZY: canard clearance

I wander if someone has tested a very loose boot on the inside of the fuselage? One side tight around the tube and the other
fixed to inside of fus. The loose material, like rubberized cloth will allow for the movement of the tube and stop any draft ??
Bulent

cdenk@ix.netcom.com wrote:

> Was said <some space around the elevator torque tube assembly>
> Mine is less than 1/8". Part of the tube opening is framed by a piece attached to the fuselage, and part to the canard. I DO
> NOT weatherstrip the elevator tube opening, concern for water freezing the elevator in position as passing into freezing air
> during climb.



Date: Mon, 13 Sep 1999 11:26:07 -0500
From: David de Sosa <d-desosa@raytheon.com>
Subject: COZY: Canard Position Off

Several years ago I acquired an early Cozy MKIV project which has
several differences from the current plans built version.

I just discovered that the distance from F-28 to the wing spar
is one inch shorter that called out in the plans.  This effectively
puts the canard position one inch closer to the wing spar.  Since
the wing spar is already attached and the fuselage built with
bulkheads in place, I am going to have to live with this situation.

Other than having to recalculate my C.G. envelope, are there any
other issues I need to be aware of especially concerning possible
adverse effects to any flight characteristics?


David 
Cozy MkIV  #080

From: "Schuler, Larry" <Larry.Schuler@uscellular.com>
Subject: RE: COZY: Canard Position Off
Date: Mon, 13 Sep 1999 13:43:00 -0500

David de Sosa wrote:

>Several years ago I acquired an early Cozy MKIV project which has 
>several differences from the current plans built version.
>snip
>Other than having to recalculate my C.G. envelope, are there any 
>other issues I need to be aware of especially concerning possible 
>adverse effects to any flight characteristics?

First and foremost, you have a tottally new airplane.  Untested flight 
characteristics.  Just "calculating" won't be good enough.  It will need to 
be "proven".

Seems to me you might expect a more "forward" aft CG limit and higher front 
seat weight limit along with higher one-person balast requirement; but you 
will need to determine what all the new limits are through extensive flight 
testing.  Be very careful of deep stall as you explore the new envelope.  
Nat had a neat movable weight setup for his testing.

Good luck and let us know what you come up with.  Interesting mod.  Any 
idea why original builder did that?

Larry

From: MARC_ZEITLIN@HP-Andover-om1.om.hp.com
Date: Mon, 13 Sep 1999 16:06:33 -0400
Subject: COZY: Canard Position Off

Larry Schuler wrote;

> First and foremost, you have a totally new airplane.  
> Untested flight characteristics.  Just "calculating" won't be good enough.  
> It will need to be "proven".

While I agree that it's a relatively major change, I don't think it's quite as 
bad as Larry's making it out to be.  Moving the canard rearward is similar in 
effect to making the canard smaller (as recommended in the plans).  _If_ the 
difference in canard position is similar in effect to the reduction in canard 
size, then you might be able to just build the original size canard (add 3" 
each tip) and be back in business.

You will have to "prove" (as Larry says) your plane just like everyone else who 
builds one, since no two plans built aircraft are ever identical.

> ...  Any idea why original builder did that?

I'm going to guess that it wasn't intentional :-).

You could, of course, rip out the canard mount points and move them forward one 
inch.  This would _not_ be an immense amount of work.....

--
Marc J. Zeitlin                          email: marcz@an.hp.com
Cardiology Products Division             phone: 978-659-3223
Agilent Technologies                       fax: 978-659-4373
3000 Minuteman Drive                  Mailstop: 0223
Andover, MA 01810          Non Impediti Ratione Cognitanis (C&C)

From: cdenk@ix.netcom.com
Date: Mon, 13 Sep 1999 16:48:08 -0500 (CDT)
Subject: Re: COZY: Canard Position Off

Was said <I just discovered that the distance from F-28 to the wing spar is one inch shorter that 
called out in the plans.>

Don't think one could calculate a new allowable weight balance envelope, thats determined mainly 
from test flights or some very detailed engineering calculations that very few have the necessary 
starting data and expertice to execute. It would mean test flights to determine if there is the 
possibility of deep stall. 1" doesn't seem like much, maybe several percent of some important 
distance, like to the C.G. of wing lift. Shorter distance would mean the canard has to provide 
more lift at all speeds, in particular takeoff and landing. More sensitive elevators are also 
possible. 

I would investigate using the firewall location (aft edge of the spar) as the starting point for 
fuselage stations, locate the canard, landing gear (both mains and nose) to that stationing. I 
don't think the seat locations is critical, when the aircraft is weighed, get several (at 
different times) people in the seats, add fuel, etc. and read the scales. Then calculate the C.G. 
of the seat and fuel loads. These will be the numbers that become your plane's lever arms for C.G. 
calcs.

Caution loosing 1" between F-28 and the instrument panel, could be an issue with radio 
installation.  

From: Epplin John A <EpplinJohnA@jdcorp.deere.com>
Subject: COZY: Elevator torque tube seal
Date: Mon, 20 Sep 1999 08:40:31 -0500

In the process of finishing the canard cosmetic fitup it occurred to me that
the torque tube through hole may be easy to take care of.  It seems to me
that any air leakage would be outward, the cockpit would be pressurized
somewhat with ram air form the fresh air vents or heated air from the bottom
NACA scoop.  One would want to minimize the air loss, however.  I put a
piece of 1/4 in. foam in place with 5 min. epoxy on the canard that closes
the gap, just under flush with the outer fuselage skin.  Did not worry about
the torque tube at the time.  The plan is to glass this both sides with one
or two BID to the canard after removing the canard.  Then make a bushing
from aluminum or wood 3/4 od and 3/16 id.  Put the hinge pin in with the
bushing outside the seal piece, cut the seal out to clear the pin and push
the pin into place.  Slide the bushing against the seal and transfer the 3/4
od. to the seal.  Remove the pin and bushing, cut out to the mark plus some
clearance and flox the edge.  This will need to be only a half circle so the
torque tube can be installed.   I have the fuselage aft part already cut to
a half circle, used the same technique to mark it some time ago.

My guess is that the leakage will be outward, if cold you will have cabin
heat on therefore icing should not be a problem.  I don't intend to collect
any ice but......

Anyone see any problems with this approach? 

John Epplin    MK4  #467   N100EP    Lost track of how many kits of
Super-fill.....most of it on the floor, sand and sand some more.

Date: Mon, 20 Sep 1999 10:34:11 -0500
From: David Domeier <david010@earthlink.net>
Subject: Re: COZY: Elevator torque tube seal

John,

    re "My guess is that the leakage will be outward, if cold you will
have cabin
heat on therefore icing should not be a problem.  I don't intend to
collect
any ice but......" "Anyone see any problems with this approach?"

    Absolutely not.  However, the air flow in this area is definitely
"in".  In fact it comes in everywhere, around the canopy, the nose gear
area, and the canopy access door hinges.

    I have no lack of fresh air, which may not be a bad idea since I am
suspect of the quality of the air coming forward for heat.  This
airplane has lose exhaust pipes at the slip joints and there must be
some exhaust leakage in that area.  However, the CO detector has stayed
bright yellow so there has been no CO detected.

    Sealing the canopy turned out to be the most important item of
controlling heat loss (or should I say cold air coming in)  One can fly
most days without heat if the sun is shining as the cockpit is like a
green house.  I can't prove this notion, but I think air comes in
forward and exits aft around the main gear strut area.  The interior is
slightly pressurized.  The elevator torque tube holes are slightly off
parallel to the air flow as the fuselage is still getting wider in this
area, hence the "in" flow.  Some guys are installing an exit hole aft to
facilitate the flow through the cockpit.

    I don't think about ice at the elevator torque tube area because
there is no way I am going to fly this airplane in icing conditions.
Period.

dd

From: cdenk@ix.netcom.com
Date: Mon, 20 Sep 1999 16:31:18 -0500 (CDT)
Subject: Re: COZY: Elevator torque tube seal

May not plan to fly in icing conditions, but in almost all parts of the country freezing conditions can be encountered 
(cruising at altitudes), and if there is any free water available (could have come from an overnight rain) and the seal allows 
it to span the gap, frozen controls could result. This is the only place I have ever had water enter the Cosy. 

Maintain an 1.8" gap all around the elevator offsets. negligible amount of air enters. Spend the effor on a decent heating 
system. See the archives for mine.

With all the talk lately of manufacturer's liability, this is one spot to avoid.

HAve cancelled more than several trips due to freezing and rain or clouds, but also have picked up some ice several times, and 
been in rain with temps in the low 40's.

From: cdenk@ix.netcom.com
Date: Mon, 20 Sep 1999 16:39:45 -0500 (CDT)
Subject: RE: COZY: Elevator torque tube seal

Was said, ice won't stick to teflon. If a nice highly polished surface, MAYBE NOT. But one needs to machine the hole, I doubt 
one could polish it to a high enough microfinish, not to allow some tooth action. Also the teflon could cause water to bridge 
the gap and lock up the controls. Generally like in an icecube tray, the bond is broken by putting the interface in tension. 
Here the interface is in shear (sliding), where much more force is required to break the bond. Try taking an ice cube in a 
tray with near parallel sides and push on the bottom, not bending the tray, I think much force will be required to break the 
bond.

Date: Mon, 20 Sep 1999 20:00:36 -0400
From: "L. Wayne Hicks" <lwhicks@erols.com>
Subject: Re: COZY: Elevator torque tube seal

Epplin John A wrote:
> 
> In the process of finishing the canard cosmetic fitup it occurred to me that...


-------> I'd like to add my two-cents....  I finished the cosmetics at
the spool pieces by taping/waxing the part, then filling the gaps with
flox.  The flox filled in like a "U" under the spool piece and the clark
filler foam formed the other half the circle (upside-down U) over the
spool piece...all with 1 mm clearance. SPIFFY! Just like I had
intended.  I was patting myself on the back for a job well done
until.....

.....Guess what?  With the torque tubes, spools, and elevators in place,
I cannot slide the canard forward enough to get the alignment tabs off
the alignment pins.  The spool pieces are locked in place by the floxed
"U".

Viewing the starboard spool piece, what I need to do is to re-make the
clark filler piece to cover from the 9 o'clock position all the way
around clockwise to the 6 o'clock position, then taper the flox to fill
the areas from 6 o'clock to 9 o'clock, with a nice straight taper from
F22 to the 6 o'clock spool position.  I'm sorry the words make this
sound complicated.  I'll update with a picture to my website soon.

Wayne Hicks
Cozy IV #678
Chapter 18
http://www.geocities.com/yosemite/falls/2027

From: cdenk@ix.netcom.com
Date: Mon, 20 Sep 1999 21:12:19 -0500 (CDT)
Subject: Re: COZY: Elevator torque tube seal

Thats basically what I did, stuff some 3/8" fuselage side foam into the gap with an 1/8" clearance. Then 1 ply BID and finish 
it. Yes it requires some planning to allow the canard to slip out.

From: "Larry & Jenny Schuler" <lschuler@g2a.net>
Subject: Re: COZY: Elevator torque tube seal
Date: Tue, 21 Sep 1999 18:57:46 -0500

Wayne Hicks wrote:

>intended.  I was patting myself on the back for a job well done
>until.....
>
>.....Guess what?  With the torque tubes, spools, and elevators in place,
>I cannot slide the canard forward enough to get the alignment tabs off
>the alignment pins.  The spool pieces are locked in place by the floxed
>"U".


Wayne,

Might try the AN3s in place of the tab pins.  Makes removing the canard a
snap.
Description is in the archives.

Larry

From: "Wilhelmson, Jack" <Wilhelmson@scra.org>
Subject: RE: COZY: Elevator torque tube seal
Date: Mon, 20 Sep 1999 17:04:04 -0400

John:

There is major positive pressure around the torque tube hole. A very tight
seal is required to keep the air from freezing your feet, even with cabin
heat.
I have found that a tight ice proof seal can be  made of solid Teflon. It
can fit the
torque tube like a bearing. +/_ .005. Ice will not stick to Teflon. I made
mine about .25
thick. The best way is make a split ring 3" dia. or more with a .75 dia.
hole. Slip on the
MKNC12A by using the split in the ring. (I assume your building a MKIV.) 
Then trim the ring to fit the canard and the fuselage. Fit it with flox
which also
will not stick to it.

Jack Wilhelmson N711CZ.
