Date   

Re: spar caps

Allan Farr
 

I’m no expert but I read a book by one of the UK’s leading fibreglass experts
and from that I understand that overloading fibreglass causes it to be
irreversibly weakened (similar to metal fatigue?). Presumably for a/c that are
regularly overloaded the structural strength safety margin is gradually being
eroded.

Allan F

Q2 not flying

-----Original Message-----
From: Q-LIST@... [mailto:Q-LIST@...] On Behalf Of
johntenhave
Sent: Thursday, February 14, 2008 4:43 PM
To: Q-LIST@...
Subject: [Q-LIST] Re: spar caps



Charlie,

I am delighted that I am not the only one whose alarm bells are
beginning to sound like tinnitus.

That said, Larry has illustrated my previous assertions beautifully.

The problem is that some poor souls still think that this
discontinuous outpouring is justification for the most dangerous
behaviour.

You make the best of points when you highlight the actual strength of
the materials which result from the wet layup process. The safety
margins are eroded before the part is cured.

Gentlemen, please ignore Larry's advice. It is just plain (and plane)
wrong.

I am presently revisiting the calcs to illustrate how close to the
edge the 1000 lb loading is to the limit and the dangers of overload.
I will restate the critical point that irrespective of the canard
strength, it is the weakest link that will fail and the result will be
catastrophic.

The headstone manufacture will not care one jot if it was a wing
failure or a canard failure that proved one's undoing...

John

--- In HYPERLINK "mailto:Q-LIST%40yahoogroups.com"Q-LIST@...,
oneskydog@..-. wrote:

Larry ,

When you stray from the plans the responsibility is awesome as the
"new"
designer you hold lives in your hand. When you fix a damaged part
original
materials must be used to restore the laminate to the design
specifications to
restore just the right amount of strength and stiffness. Unless you
have a note
from Burt do not redesign these planes you are in way over your
head. Your
mumbo jumbo with terms like using stiffness when it should be
strength, using
laminate strength claims made in a catalog as "A"basis allowable's
to do your
back of the envelope section calculations make me nervous. I have
also seen
the quality of your repairs on the flipped Tri-Q and frankly was
alarmed. I
cannot sit silent and let you preach design mods to the builders.

I teach advanced composite manufacturing and processing as well as
repair
but am not qualified to design composite parts. In one class the
students build
a carbon fiber "I" beam from unidirectional pre-impregnated carbon
fiber
tape. They also have to calculate the strength and first ply failure
and predict
the maximum load the beam will take. We then take the beams to the
test lab
and using a really cool 4 point bend fixture we crush the living
**** out of
them. The students who are engineers are always surprised at the
spread
between the predicted and the actual values

For your 30 G claim at 1000 lbs I offer this information. Our "I" beam
design has a +/- 45 degree shear web 0.080 inches thick, caps are
0.130 inches
thick with 19 unidirectional plies for tension/compression-. The
overall beam is
3" high and 3" wide so we are in the range of a Q canard section
somewhere
between the root and tip.

The breaking loads vary from around 5,000 lbs to 9,000 lbs. Quite a
variance
for the same laminate built on hard tooling vacuum bagged and
autoclave
cured. More sobering is that it is not even close to 30 G's if your
working load
is a thousand pounds. You cannot duplicate the quality of these
parts in your
garage or hanger and we haven't even talked about adhesively bonded
joints.

I do not want to be to harsh and you might be a hot commercial
pilot with
what a gazillion hours and a ME degree but are you a practicing
composites
structural designer? Playing composite airplane designer gets
people killed and
maimed. Follow the dammed plans for your structural parts, exercise
your
creativity on tertiary structure and finish.

The above is my humble opinion and I do not wish to offend qualified
people.

Regards

One Sky Dog

Charlie Johnson Materials/Process Engineer
Air Force Research Laboratory / Advanced Composites Laboratory



In a message dated 2/13/2008 9:44:12 A.M. Mountain Standard Time,
larry2@... writes:

So, how stiff (strong) will the result be? We do not have real
numbers, but e glass is about 1/4 the stiffness and strength of
carbon fiber. AS&S lists a 5 inch wide CF as being 54,000 PSI. This
means that a square inch of this material would withstand a
stretching force of 54K lbs. Given the 5 inch width, it would take
about 17 (16.67) layers in the lamination to achieve the stiffness.
On the Q2, there are equal layers of UNI on both the top and bottom
surface spread out over the skin surface. The thickness of the
airfoil at any point adds to the overall stiffness because the
resistance layers of the UNI are forced apart. Think bending moment.
The effective strength of the construction is the UNI layer strength
at a given point times 1/2 the core (foam) thickness. From this info,
anyone can start creating a strength ratio for either of the Q
airfoils. However, as has been pointed out, the center section has an
added hat section for increased strength. The hat section acts more
like a box spar. The UNI "spar caps" are just that. They use the foam
to create the effect of a thick, light-weight spar.





************-**The year's hottest artists on the red carpet at the
Grammy
Awards. Go to AOL Music.
(HYPERLINK
"http://music.aol.com/grammys?NCID=aolcmp00300000002565"http://music.-aol.com/gr
ammys?-NCID=aolcmp00300-000002565)






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p.m.


Re: Takeoff and landing speed?

Sam Hoskins
 

I get off and lane around 80mph. Higher when hot and loaded. There
have been days when I saw 95+ on the airspeed indicator before I was
off.

Sam

On Feb 13, 2008 5:07 PM, Justin Iida <chachi386@...> wrote:






What is the takeoff and landing speed of the q2?

---------------------------------
Never miss a thing. Make Yahoo your homepage.




Re: spar caps

John ten
 

Charlie,

I am delighted that I am not the only one whose alarm bells are
beginning to sound like tinnitus.

That said, Larry has illustrated my previous assertions beautifully.

The problem is that some poor souls still think that this
discontinuous outpouring is justification for the most dangerous
behaviour.

You make the best of points when you highlight the actual strength of
the materials which result from the wet layup process. The safety
margins are eroded before the part is cured.

Gentlemen, please ignore Larry's advice. It is just plain (and plane)
wrong.

I am presently revisiting the calcs to illustrate how close to the
edge the 1000 lb loading is to the limit and the dangers of overload.
I will restate the critical point that irrespective of the canard
strength, it is the weakest link that will fail and the result will be
catastrophic.

The headstone manufacture will not care one jot if it was a wing
failure or a canard failure that proved one's undoing...



John




--- In Q-LIST@..., oneskydog@... wrote:

Larry ,

When you stray from the plans the responsibility is awesome as the
"new"
designer you hold lives in your hand. When you fix a damaged part
original
materials must be used to restore the laminate to the design
specifications to
restore just the right amount of strength and stiffness. Unless you
have a note
from Burt do not redesign these planes you are in way over your
head. Your
mumbo jumbo with terms like using stiffness when it should be
strength, using
laminate strength claims made in a catalog as "A"basis allowable's
to do your
back of the envelope section calculations make me nervous. I have
also seen
the quality of your repairs on the flipped Tri-Q and frankly was
alarmed. I
cannot sit silent and let you preach design mods to the builders.

I teach advanced composite manufacturing and processing as well as
repair
but am not qualified to design composite parts. In one class the
students build
a carbon fiber "I" beam from unidirectional pre-impregnated carbon
fiber
tape. They also have to calculate the strength and first ply failure
and predict
the maximum load the beam will take. We then take the beams to the
test lab
and using a really cool 4 point bend fixture we crush the living
**** out of
them. The students who are engineers are always surprised at the
spread
between the predicted and the actual values

For your 30 G claim at 1000 lbs I offer this information. Our "I" beam
design has a +/- 45 degree shear web 0.080 inches thick, caps are
0.130 inches
thick with 19 unidirectional plies for tension/compression. The
overall beam is
3" high and 3" wide so we are in the range of a Q canard section
somewhere
between the root and tip.

The breaking loads vary from around 5,000 lbs to 9,000 lbs. Quite a
variance
for the same laminate built on hard tooling vacuum bagged and
autoclave
cured. More sobering is that it is not even close to 30 G's if your
working load
is a thousand pounds. You cannot duplicate the quality of these
parts in your
garage or hanger and we haven't even talked about adhesively bonded
joints.

I do not want to be to harsh and you might be a hot commercial
pilot with
what a gazillion hours and a ME degree but are you a practicing
composites
structural designer? Playing composite airplane designer gets
people killed and
maimed. Follow the dammed plans for your structural parts, exercise
your
creativity on tertiary structure and finish.

The above is my humble opinion and I do not wish to offend qualified
people.

Regards

One Sky Dog

Charlie Johnson Materials/Process Engineer
Air Force Research Laboratory / Advanced Composites Laboratory



In a message dated 2/13/2008 9:44:12 A.M. Mountain Standard Time,
larry2@... writes:

So, how stiff (strong) will the result be? We do not have real
numbers, but e glass is about 1/4 the stiffness and strength of
carbon fiber. AS&S lists a 5 inch wide CF as being 54,000 PSI. This
means that a square inch of this material would withstand a
stretching force of 54K lbs. Given the 5 inch width, it would take
about 17 (16.67) layers in the lamination to achieve the stiffness.
On the Q2, there are equal layers of UNI on both the top and bottom
surface spread out over the skin surface. The thickness of the
airfoil at any point adds to the overall stiffness because the
resistance layers of the UNI are forced apart. Think bending moment.
The effective strength of the construction is the UNI layer strength
at a given point times 1/2 the core (foam) thickness. From this info,
anyone can start creating a strength ratio for either of the Q
airfoils. However, as has been pointed out, the center section has an
added hat section for increased strength. The hat section acts more
like a box spar. The UNI "spar caps" are just that. They use the foam
to create the effect of a thick, light-weight spar.





**************The year's hottest artists on the red carpet at the
Grammy
Awards. Go to AOL Music.
(http://music.aol.com/grammys?NCID=aolcmp00300000002565)


[Non-text portions of this message have been removed]


Re: Takeoff and landing speed?

Larry Severson
 

At 05:04 PM 2/13/2008, you wrote:

My Q2 pitch bucked at 68 mph indicated.
There is one report of flying at 60mph (no weight listed) down the length of the runway.

My TriQ, at 980lbs actual, flew nose high at a stable 62mph with no evidence of a pitch buck. Each plane is different, especially as the weight changes. That is why it is so important to test the particular plane for stall speed at a range of weights, all of the way up to listed max GW.

For initial landing, before stall testing, an approach at 80mph with an expected landing at 70+mph makes a lot of sense.



Larry Severson
Fountain Valley, CA 92708
(714) 968-9852
larry2@...


Re: Takeoff and landing speed?

Doug Humble <hawkidoug@...>
 

My Q2 pitch bucked at 68 mph indicated.

Doug "Hawkeye" Humble
A Sign Above www.asignabove.net
Omaha NE
N25974

----- Original Message -----
From: larry severson
To: Q-LIST@...
Sent: Wednesday, February 13, 2008 5:21 PM
Subject: Re: [Q-LIST] Takeoff and landing speed?


At 03:07 PM 2/13/2008, you wrote:

>What is the takeoff and landing speed of the q2?

The POH says 65mph.

Larry Severson
Fountain Valley, CA 92708
(714) 968-9852
larry2@...


Re: spar caps

Peter Harris <peterjfharris@...>
 

Michael

I passed on a copy of the data pages for Styrofoam showing each grade and
the mechanical specifications and I think you will find it in the resources
link on the website.

Peter

_____

From: Q-LIST@... [mailto:Q-LIST@...] On Behalf Of
Michael Quinn
Sent: Thursday, 14 February 2008 8:09 AM
To: q-list@...
Subject: RE: [Q-LIST] spar caps




Larry,
Good clear explanation. The last paragraph you said LS1 requires the spar. I
assume you are refering to the traditional landing gear and not the tri-q as
the load requirements when the cannard is not doubling as landing gear is
much less and can be managed with a design like Mark Wadallow (sp?). Yes?

I did a couple searches (because I know it has been covered - but cannot
find the answer) regarding the difference between the blue and orange foam.
I also remember reading in the newsletter about a failure with a repair
using pour foam rather than the method that the instructions indicate with
cutting out and replacing with similar foam.

M.

________________________________
To: Q-LIST@yahoogroups. <mailto:Q-LIST%40yahoogroups.com> com
From: larry2@socal. <mailto:larry2%40socal.rr.com> rr.com
Date: Wed, 13 Feb 2008 08:43:19 -0800
Subject: [Q-LIST] spar caps


In a traditional wing, the skin is NOT load bearing. The spar carries
the total load. In many cases, it receives additional strength by the
use of spar caps which form an I beam. an I beam is significantly
stronger that a straight piece of wood or metal. Other methods
include creating a box for greater strength while having lighter
weight that an equally strong straight spar.

In the case of foam, the strength (resistance to bending and breaking
goes up with the distance between outside layers of glass squared.
The primary purpose of the foam is to separate the glass layers. We
have to use "stiff" foam because the packing foam tends to compress
under pressure, which would decrease the distance between the foam
layers. the 2 layers of glass added at a 45 degree angle add
torsional stiffness to the wing, but it is the UNI glass that is
placed along the wing (canard) span that adds stiffness to the wing
(canard). The further apart the UNI (spar caps) are placed the
stiffer the lifting surface will be.

So, how stiff (strong) will the result be? We do not have real
numbers, but e glass is about 1/4 the stiffness and strength of
carbon fiber. AS&S lists a 5 inch wide CF as being 54,000 PSI. This
means that a square inch of this material would withstand a
stretching force of 54K lbs. Given the 5 inch width, it would take
about 17 (16.67) layers in the lamination to achieve the stiffness.
On the Q2, there are equal layers of UNI on both the top and bottom
surface spread out over the skin surface. The thickness of the
airfoil at any point adds to the overall stiffness because the
resistance layers of the UNI are forced apart. Think bending moment.
The effective strength of the construction is the UNI layer strength
at a given point times 1/2 the core (foam) thickness. From this info,
anyone can start creating a strength ratio for either of the Q
airfoils. However, as has been pointed out, the center section has an
added hat section for increased strength. The hat section acts more
like a box spar. The UNI "spar caps" are just that. They use the foam
to create the effect of a thick, light-weight spar.

From the discussion above, it should be easily understood why the
LS1 airfoil REQUIRES the CF spar addition. The airfoil simply is
not as thick.

Larry Severson
Fountain Valley, CA 92708
(714) 968-9852
larry2@socal. <mailto:larry2%40socal.rr.com> rr.com


__________________________________________________________
Need to know the score, the latest news, or you need your HotmailR-get your
"fix".
http://www.msnmobil <http://www.msnmobilefix.com/Default.aspx>
efix.com/Default.aspx


Re: Takeoff and landing speed?

Larry Severson
 

At 03:07 PM 2/13/2008, you wrote:

What is the takeoff and landing speed of the q2?
The POH says 65mph.


Larry Severson
Fountain Valley, CA 92708
(714) 968-9852
larry2@...


Re: Q2 Video

jon@...
 

Wow John - GOOD EYE!! Those are UFO's. We get them all the time here in New Mexico, we just ignore them.



Jon

-----Original Message-----
From: John Loram <johnl@...>
Sent: Wednesday, February 13, 2008 6:11pm
To: Q-LIST@...
Subject: RE: [Q-LIST] Q2 Video

Oh Yeh! I recognize the rivet pattern That was definitely a C190 or 195....

-john-
p.s. What was that other little white plane that nearly hit you???


_____

From: Q-LIST@... [mailto:Q-LIST@...] On Behalf Of
Jon Finley
Sent: Saturday, February 09, 2008 6:10 PM
To: q-list@...
Subject: [Q-LIST] Q2 Video



More video...

Pamela (my wife) took this yesterday on our way home from breakfast from a
neighbors C195. I thought the second half came out very nicely so had to
share.

....

Jon





.


Re: Q2 Video

John Loram <johnl@...>
 

Oh Yeh! I recognize the rivet pattern That was definitely a C190 or 195....

-john-
p.s. What was that other little white plane that nearly hit you???


_____

From: Q-LIST@... [mailto:Q-LIST@...] On Behalf Of
Jon Finley
Sent: Saturday, February 09, 2008 6:10 PM
To: q-list@...
Subject: [Q-LIST] Q2 Video



More video...

Pamela (my wife) took this yesterday on our way home from breakfast from a
neighbors C195. I thought the second half came out very nicely so had to
share.

....

Jon





.

<http://geo.yahoo.com/serv?s=97359714/grpId=2124158/grpspId=1705065618/msgId
=30376/stime=1202609378/nc1=4767086/nc2=4507179/nc3=5028924>


Takeoff and landing speed?

Justin Iida
 

What is the takeoff and landing speed of the q2?

---------------------------------
Never miss a thing. Make Yahoo your homepage.


Re: spar caps

Larry Severson
 


The last paragraph you said LS1 requires the spar. I assume you are refering to the traditional landing gear and not the tri-q as the load requirements when the cannard is not doubling as landing gear is much less and can be managed with a design like Mark Wadallow (sp?). Yes?
Absolutely. That is why this discussion started when I said that the Tri was limited by main gear and power, not canard strength. However, the LS1, without the CF spar is weaker than the GU. How much, I can not say for sure. I would expect about 30-40 percent, which would still be adequate for a Tri, assuming that the QAC figure of 30G for the GU canard is accurate. That said, why would you consider the less efficient LS1 canard when you don't have a CF spar available. Even with the VGs, necessary for flight into moisture, your plane will be faster with the GU.


I did a couple searches (because I know it has been covered - but cannot find the answer) regarding the difference between the blue and orange foam.
I have found no info on that either, but I have been told that they are both 2lb foam and hot wireable. The same? I don't know.

I also remember reading in the newsletter about a failure with a repair using pour foam rather than the method that the instructions indicate with cutting out and replacing with similar foam.
Pour foam is not as consistent as the original foam, but it is STIFF, which is the most important factor, as my previous post stated. I see no reason that it can not be used, especially inside the cockpit. On the exposed airfoil, I would not use it due to its poor sanding characteristics.


Larry Severson
Fountain Valley, CA 92708
(714) 968-9852
larry2@...


Re: spar caps

Michael Quinn
 

Larry,
Good clear explanation. The last paragraph you said LS1 requires the spar. I assume you are refering to the traditional landing gear and not the tri-q as the load requirements when the cannard is not doubling as landing gear is much less and can be managed with a design like Mark Wadallow (sp?). Yes?

I did a couple searches (because I know it has been covered - but cannot find the answer) regarding the difference between the blue and orange foam. I also remember reading in the newsletter about a failure with a repair using pour foam rather than the method that the instructions indicate with cutting out and replacing with similar foam.

M.

________________________________
To: Q-LIST@...
From: larry2@...
Date: Wed, 13 Feb 2008 08:43:19 -0800
Subject: [Q-LIST] spar caps


In a traditional wing, the skin is NOT load bearing. The spar carries
the total load. In many cases, it receives additional strength by the
use of spar caps which form an I beam. an I beam is significantly
stronger that a straight piece of wood or metal. Other methods
include creating a box for greater strength while having lighter
weight that an equally strong straight spar.

In the case of foam, the strength (resistance to bending and breaking
goes up with the distance between outside layers of glass squared.
The primary purpose of the foam is to separate the glass layers. We
have to use "stiff" foam because the packing foam tends to compress
under pressure, which would decrease the distance between the foam
layers. the 2 layers of glass added at a 45 degree angle add
torsional stiffness to the wing, but it is the UNI glass that is
placed along the wing (canard) span that adds stiffness to the wing
(canard). The further apart the UNI (spar caps) are placed the
stiffer the lifting surface will be.

So, how stiff (strong) will the result be? We do not have real
numbers, but e glass is about 1/4 the stiffness and strength of
carbon fiber. AS&S lists a 5 inch wide CF as being 54,000 PSI. This
means that a square inch of this material would withstand a
stretching force of 54K lbs. Given the 5 inch width, it would take
about 17 (16.67) layers in the lamination to achieve the stiffness.
On the Q2, there are equal layers of UNI on both the top and bottom
surface spread out over the skin surface. The thickness of the
airfoil at any point adds to the overall stiffness because the
resistance layers of the UNI are forced apart. Think bending moment.
The effective strength of the construction is the UNI layer strength
at a given point times 1/2 the core (foam) thickness. From this info,
anyone can start creating a strength ratio for either of the Q
airfoils. However, as has been pointed out, the center section has an
added hat section for increased strength. The hat section acts more
like a box spar. The UNI "spar caps" are just that. They use the foam
to create the effect of a thick, light-weight spar.

From the discussion above, it should be easily understood why the
LS1 airfoil REQUIRES the CF spar addition. The airfoil simply is
not as thick.

Larry Severson
Fountain Valley, CA 92708
(714) 968-9852
larry2@...


_________________________________________________________________
Need to know the score, the latest news, or you need your Hotmail®-get your "fix".
http://www.msnmobilefix.com/Default.aspx


Re: spar caps

One Sky Dog
 

Larry ,

When you stray from the plans the responsibility is awesome as the "new"
designer you hold lives in your hand. When you fix a damaged part original
materials must be used to restore the laminate to the design specifications to
restore just the right amount of strength and stiffness. Unless you have a note
from Burt do not redesign these planes you are in way over your head. Your
mumbo jumbo with terms like using stiffness when it should be strength, using
laminate strength claims made in a catalog as "A"basis allowable's to do your
back of the envelope section calculations make me nervous. I have also seen
the quality of your repairs on the flipped Tri-Q and frankly was alarmed. I
cannot sit silent and let you preach design mods to the builders.

I teach advanced composite manufacturing and processing as well as repair
but am not qualified to design composite parts. In one class the students build
a carbon fiber "I" beam from unidirectional pre-impregnated carbon fiber
tape. They also have to calculate the strength and first ply failure and predict
the maximum load the beam will take. We then take the beams to the test lab
and using a really cool 4 point bend fixture we crush the living **** out of
them. The students who are engineers are always surprised at the spread
between the predicted and the actual values

For your 30 G claim at 1000 lbs I offer this information. Our "I" beam
design has a +/- 45 degree shear web 0.080 inches thick, caps are 0.130 inches
thick with 19 unidirectional plies for tension/compression. The overall beam is
3" high and 3" wide so we are in the range of a Q canard section somewhere
between the root and tip.

The breaking loads vary from around 5,000 lbs to 9,000 lbs. Quite a variance
for the same laminate built on hard tooling vacuum bagged and autoclave
cured. More sobering is that it is not even close to 30 G's if your working load
is a thousand pounds. You cannot duplicate the quality of these parts in your
garage or hanger and we haven't even talked about adhesively bonded joints.

I do not want to be to harsh and you might be a hot commercial pilot with
what a gazillion hours and a ME degree but are you a practicing composites
structural designer? Playing composite airplane designer gets people killed and
maimed. Follow the dammed plans for your structural parts, exercise your
creativity on tertiary structure and finish.

The above is my humble opinion and I do not wish to offend qualified people.

Regards

One Sky Dog

Charlie Johnson Materials/Process Engineer
Air Force Research Laboratory / Advanced Composites Laboratory

In a message dated 2/13/2008 9:44:12 A.M. Mountain Standard Time,
larry2@... writes:

So, how stiff (strong) will the result be? We do not have real
numbers, but e glass is about 1/4 the stiffness and strength of
carbon fiber. AS&S lists a 5 inch wide CF as being 54,000 PSI. This
means that a square inch of this material would withstand a
stretching force of 54K lbs. Given the 5 inch width, it would take
about 17 (16.67) layers in the lamination to achieve the stiffness.
On the Q2, there are equal layers of UNI on both the top and bottom
surface spread out over the skin surface. The thickness of the
airfoil at any point adds to the overall stiffness because the
resistance layers of the UNI are forced apart. Think bending moment.
The effective strength of the construction is the UNI layer strength
at a given point times 1/2 the core (foam) thickness. From this info,
anyone can start creating a strength ratio for either of the Q
airfoils. However, as has been pointed out, the center section has an
added hat section for increased strength. The hat section acts more
like a box spar. The UNI "spar caps" are just that. They use the foam
to create the effect of a thick, light-weight spar.





**************The year's hottest artists on the red carpet at the Grammy
Awards. Go to AOL Music.
(http://music.aol.com/grammys?NCID=aolcmp00300000002565)


spar caps

Larry Severson
 

In a traditional wing, the skin is NOT load bearing. The spar carries the total load. In many cases, it receives additional strength by the use of spar caps which form an I beam. an I beam is significantly stronger that a straight piece of wood or metal. Other methods include creating a box for greater strength while having lighter weight that an equally strong straight spar.

In the case of foam, the strength (resistance to bending and breaking goes up with the distance between outside layers of glass squared. The primary purpose of the foam is to separate the glass layers. We have to use "stiff" foam because the packing foam tends to compress under pressure, which would decrease the distance between the foam layers. the 2 layers of glass added at a 45 degree angle add torsional stiffness to the wing, but it is the UNI glass that is placed along the wing (canard) span that adds stiffness to the wing (canard). The further apart the UNI (spar caps) are placed the stiffer the lifting surface will be.

So, how stiff (strong) will the result be? We do not have real numbers, but e glass is about 1/4 the stiffness and strength of carbon fiber. AS&S lists a 5 inch wide CF as being 54,000 PSI. This means that a square inch of this material would withstand a stretching force of 54K lbs. Given the 5 inch width, it would take about 17 (16.67) layers in the lamination to achieve the stiffness. On the Q2, there are equal layers of UNI on both the top and bottom surface spread out over the skin surface. The thickness of the airfoil at any point adds to the overall stiffness because the resistance layers of the UNI are forced apart. Think bending moment. The effective strength of the construction is the UNI layer strength at a given point times 1/2 the core (foam) thickness. From this info, anyone can start creating a strength ratio for either of the Q airfoils. However, as has been pointed out, the center section has an added hat section for increased strength. The hat section acts more like a box spar. The UNI "spar caps" are just that. They use the foam to create the effect of a thick, light-weight spar.

From the discussion above, it should be easily understood why the LS1 airfoil REQUIRES the CF spar addition. The airfoil simply is not as thick.

Larry Severson
Fountain Valley, CA 92708
(714) 968-9852
larry2@...


Re: Q1 Hydraulic Brakes - advice please

cburgoontrike3 <CBurgoon@...>
 

I am working in China and wanted a new fork/shock assembly for my
trike (motorized hang glider/undercarriage thingy with an N Number).
I looked at countless scooters and picked a Yamaha front fork
assembly. It's really slick. I bought each and every piece
separately over the parts counter. In the US it would have cost a
fortune, but I got everything, and I mean everything, for around
$180. There is an unbelievable selection of nice parts here.

Chuck Burgoon
Tri-Q2
Houston Texas




--- In Q-LIST@..., Isaksson Roger <scratchdeeper@...>
wrote:

Right now there are a lot of Hi Tech small stuff coming from China.
small bikes and schooters with discbrakes, hydraulic and cable.

Go to sites that are suppliers of go-cart, imported scooters,
(those step on type, that looks like a skate board with a small
engine and a steering column, small kids bikes ( looks like the real
thing, and the stuff on it looks like the real thing too)

The MC field have stuff you can probably use or with reasonable
ease convert, it is pretty common that bikes have a hydralic
reservoir at the grips, for both clutch and front wheel brake. You
probably can't use the discs, but you have a pretty good chance of
getting a compact break unit by converting the handbreak system.

Take an hour or so hours on a wrecking yard for motor bikes and
look at what gives.

AZUZA wheels had working stuff once upon a time, dont even know
if they are still in business.

By the way, well done on getting that many hours on a Rotax. Is
that with the same engine or with a couple of overhauls?

I had an idea that you will not get too many hours out of one of
those contraptions but if you have over 500 hours on it, it's one for
your hat.




g13mvg <paul@...> wrote:
I started in 1986 with the plans scrubbers. They gave me
something to
play with while waiting to see if I was slowing down.
I've been flying for 5 years with drum brakes - but they are heavy
to
use, and 'snatch'; making life interesting visiting the weeds more
often than I'd like.
I'm now going to go with hydraulic brakes - I'd have thought that
bicycle brakes have now developed sufficiently that they are a good
Q1
possibility.
Sorry for not getting into this group very often (I've been a
passive
bystander). I'd likes the groups considered advice on what is the
best
way to go with the Q1 brakes based on your considered collective
experience.
Current wheels are 11x4.00-5 Shing Chen (Chen Shing?).

What is the best hydraulic intsllation for my Q1 G-BMVG?
Currently 520 hours, Rotax 503. Still boring little holes in the
sky.

Cheers,
Paul Wright






---------------------------------
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Search.



Re: Q1 Hydraulic Brakes - advice please

Isaksson Roger <scratchdeeper@...>
 

Right now there are a lot of Hi Tech small stuff coming from China. small bikes and schooters with discbrakes, hydraulic and cable.

Go to sites that are suppliers of go-cart, imported scooters, (those step on type, that looks like a skate board with a small engine and a steering column, small kids bikes ( looks like the real thing, and the stuff on it looks like the real thing too)

The MC field have stuff you can probably use or with reasonable ease convert, it is pretty common that bikes have a hydralic reservoir at the grips, for both clutch and front wheel brake. You probably can't use the discs, but you have a pretty good chance of getting a compact break unit by converting the handbreak system.

Take an hour or so hours on a wrecking yard for motor bikes and look at what gives.

AZUZA wheels had working stuff once upon a time, dont even know if they are still in business.

By the way, well done on getting that many hours on a Rotax. Is that with the same engine or with a couple of overhauls?

I had an idea that you will not get too many hours out of one of those contraptions but if you have over 500 hours on it, it's one for your hat.




g13mvg <paul@...> wrote:
I started in 1986 with the plans scrubbers. They gave me something to
play with while waiting to see if I was slowing down.
I've been flying for 5 years with drum brakes - but they are heavy to
use, and 'snatch'; making life interesting visiting the weeds more
often than I'd like.
I'm now going to go with hydraulic brakes - I'd have thought that
bicycle brakes have now developed sufficiently that they are a good Q1
possibility.
Sorry for not getting into this group very often (I've been a passive
bystander). I'd likes the groups considered advice on what is the best
way to go with the Q1 brakes based on your considered collective
experience.
Current wheels are 11x4.00-5 Shing Chen (Chen Shing?).

What is the best hydraulic intsllation for my Q1 G-BMVG?
Currently 520 hours, Rotax 503. Still boring little holes in the sky.

Cheers,
Paul Wright






---------------------------------
Looking for last minute shopping deals? Find them fast with Yahoo! Search.


Re: Q1 Hydraulic Brakes - advice please

Kerri & Mark <ksm@...>
 

Hi Paul I have some nice mountainbike brakes that are going into the Q1 can send pics if needed and will be splitting the handel for left and right brake..

Mark Fitzgerald Q1
Timaru
New Zealand


Re: grass or pavement?

Peter Harris <peterjfharris@...>
 

No Gofers down here. The Kangaroos eat them..

My tyres lasted longer on the grass, I think it is kind to the undercarriage
and airframe but not good wet

Peter



_____

From: Q-LIST@... [mailto:Q-LIST@...] On Behalf Of
Mike Dwyer
Sent: Wednesday, 13 February 2008 9:55 AM
To: Q-LIST@...
Subject: Re: [Q-LIST] grass or pavement?



The Q2/200's can be built with wide or skinny tires. Mine has the
skinny tires cause I care more about going fast. I've flown off about 4
grass strips, say 5 grass landings in total compared to 1500 paved
landings. Good grass is ok but hit the hole that the gofer just dug and
your ---- out of luck. I don't think you'd ever get as many hours
before crash on grass as you can on paved. TTC, time to crash, a new term!
Mike Q200 N3QP 1000+ hours.



_____

From: Q-LIST@yahoogroups. <mailto:Q-LIST%40yahoogroups.com> com
[mailto:Q-LIST@yahoogroups. <mailto:Q-LIST%40yahoogroups.com> com] On Behalf
Of
Justin Iida
Sent: Tuesday, 12 February 2008 11:43 AM
To: Quickies Quickies Quickies
Subject: [Q-LIST] grass or pavement?



Will the q2 operate on a grass field or do you have to fly off of a paved
strip?

---------------------------------
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Re: What is a Tri Q200/LS1 Wing Max Gross Weight

Larry Severson
 

no spar, spar caps? Surely the presence of spar caps implies the
presence of a spar?
In the sense of a traditional spar, there is none. The spar caps use
the enclosed foam to create a broad spar. But, it is important to
distinguish the difference in the Rutan design from traditional.


greatest G forces at the tip? Remind the list where they break?
With the exception of the Q that had the foam in the center eroded by
fuel contamination, I have read only of canard breaking near the tips
after hard landings (with a GI canard). Given the placement of the
gear at the tips, all of the spar caps should have gone to the tip.
Even with a moderate landing the transient G loading at the tip can
be significant.

Remind
the list why the wing is tapered?
The wing is tapered to decrease drag and increase efficiency. The
optimum wing is:
1. laminar airflow
2. high aspect ratio
3. elliptical
The Q design uses a tapered canard/wing to closely approximate the
elliptical wing. The Spitfire is the only high performance A/C with
an elliptical wing because of the difficulty in production. Given the
hot wired foam/glass construction by home builders, an elliptical
wing was never much of a contender. Not perfect, but very good. The
canard is moderately high aspect ration, and for the GU, it is
laminar flow. The GU airfoil is used on all of the wind driven
generators because of its high lift/low drag capability. The main
wing, on the other hand is not very efficient (developing only 35% of
the lift with the same wing area). The main wing design was chosen
for its contribution (low) to a balanced aircraft with the heavy
engine up front and a light aft section. Compromise, compromise, compromise.

One other thing lacking is the presence of winglets. (Actually the
tip gear system is a form of winglet). All truly modern designs from
sail planes to commercial jets have winglets to reduce wing tip
vorticies (DRAG). The DC10 extended its range by 15% with the
addition of winglets. OF COURSE, WE DO NOT HAVE WIND TUNNELS TO
DISCOVER THE OPTIMUM WINGLET FOR THE PLANE.

Remind the list again where gravity
acts?

It acts at the center of weight (BL0), but that is not as important
as the fact that there is a bending moment across the wing operating
on the weight. The bending moment is highest at BL0. But that is
taken care of both with the center section with its added U section
and the internal hull stress arches. As one goes out the wing, the
bending stress goes down in a straight line from max to zero at the
tip. This would be a no brainer IF THERE WAS NO TIP GEAR. That
bending moment is translated to the tip with every landing. This is
why the canard flexes when weight is added to the plane with either
people or landing forces. A bounced landing can cause significant
flex, or even a break (as has happened).

With the TriQ, the tip problem does not exist! However, this in no
way addresses ability of the main gear to handle the stresses of
extra weight or hard landings. It also does not address the
stall/landing speed that results from adding the weight. There are
reports of a few cases of people adding span to the canard and wing
to reduce landing speeds (mentioned in the TriQ builders manual).
Given the canard design, flaps are not available (even though, to
some extent, the elevator acts as a flap when fully deflected).

Analysis of a wing with two spars?
I got it from a person who had an aircraft with 2 spars. For the Q
one would need to add the stresses applied to the 2 spars for the
distance from the mid point (BL0)

Forgive me Larry, reading this stuff is like looking into a broken
mirror. There are fragments of clarity but the big picture is
indecipherable.
When a discussion is narrowly focused, I chose to answer the narrow
focus. I also try to answer with a bit of brevity.


The repeated utterance of "engo-babble" might provide some degree of
comfort to those who derive comfort from buddhist chants, the rosary
or other mantras but it would be a mistake to confuse "OMMMMM" with
engineering justification.
I have never been comfortable with "OMMMMMM". It has been a long
time, but I did score 97 percentile on the Graduate Records exam in
Mechanical Engineering before I graduated. That does not make me an
expert, but it does lend a mite bit to my understanding of the
problem. That said, I am studying more on how to measure the strength
of various composite materials.


It Ain't.

John

--- In <mailto:Q-LIST%40yahoogroups.com>Q-LIST@...,
larry severson <larry2@...> wrote:

At 02:10 PM 2/12/2008, you wrote:

Larry, when you make these kind of statements, it would be helpful
if you sourced your comments. Otherwise they just sound like
hearsay. It may be true, but QAC has been gone a long time. Did you
read this somewhere that you can refer everyone to? Maybe this is
what they tested the spar to the breaking point????
1. It was in an early 1981 QAC newsletter.
2. The Q2 does not have a spar; it has spar caps over a foam core.
It's lay up schedule is improper since the caps do not go all of the
way out to the tip where the greatest expected G forces occur during
a hard landing.
3. That 30G was based on a 1000 ln airplane. The main wing was listed
at 20 G in the same article.

I have it, but it is at the Chino airport.
By the way, even Air Force pilots with G suits can not hit 8 Gs
without blacking out. I doubt that I could go 4 Gs. However, no one
should design a plane for less than 2X the expected max G loading for
safety purposes.


Larry Severson
Fountain Valley, CA 92708
(714) 968-9852
larry2@...
Larry Severson
Fountain Valley, CA 92708
(714) 968-9852
larry2@...


Re: What is a Tri Q200/LS1 Wing Max Gross Weight

Katherine O'Grady <ogrady@...>
 

There is probably good reason for the confusion, since QAC referred to it as a spar cap, and some folks called it a spar, but it was really just a hat-shaped stiffener for the top skin that stopped half way out. As a result, a number of canards failed in buckling immediately outboard of that point. The closest thing to a real spar was the doubled up glass at the rear of the main cores.

Tom O'Grady
#2099

----- Original Message -----
From: johntenhave <johntenhave@...>
Date: Tuesday, February 12, 2008 2:45 pm
Subject: [Q-LIST] Re: What is a Tri Q200/LS1 Wing Max Gross Weight
To: Q-LIST@...

Larry,

I am having a great deal of trouble unraveling your discontinuous
reasoning.

no spar, spar caps? Surely the presence of spar caps implies the
presence of a spar?

greatest G forces at the tip? Remind the list where they break? Remind
the list why the wing is tapered? Remind the list again where gravity
acts?

Analysis of a wing with two spars?

Forgive me Larry, reading this stuff is like looking into a broken
mirror. There are fragments of clarity but the big picture is
indecipherable.

The repeated utterance of "engo-babble" might provide some degree of
comfort to those who derive comfort from buddhist chants, the rosary
or other mantras but it would be a mistake to confuse "OMMMMM" with
engineering justification.

It Ain't.

John











--- In Q-LIST@..., larry severson <larry2@...> wrote:

At 02:10 PM 2/12/2008, you wrote:

Larry, when you make these kind of statements, it would be
helpful
if you sourced your comments. Otherwise they just sound like
hearsay. It may be true, but QAC has been gone a long time. Did
you
read this somewhere that you can refer everyone to? Maybe this
is
what they tested the spar to the breaking point????
1. It was in an early 1981 QAC newsletter.
2. The Q2 does not have a spar; it has spar caps over a foam
core.
It's lay up schedule is improper since the caps do not go all of
the
way out to the tip where the greatest expected G forces occur
during
a hard landing.
3. That 30G was based on a 1000 ln airplane. The main wing was
listed
at 20 G in the same article.

I have it, but it is at the Chino airport.
By the way, even Air Force pilots with G suits can not hit 8 Gs
without blacking out. I doubt that I could go 4 Gs. However, no
one
should design a plane for less than 2X the expected max G loading
for
safety purposes.


Larry Severson
Fountain Valley, CA 92708
(714) 968-9852
larry2@...



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