Windrose II 15-meter Motorglider Plans For Sale [Archive]

Doug Hoffman

October 14th 03, 10:58 PM

Redsell is predictable. To wit, my e-mail to the questioner,
predating Redsell's post slamming the Windrose.

-Doug

From: Doug Hoffman >
Date: Mon Oct 13, 2003 9:29:34 PM America/Detroit
To:
Subject: Windrose

I'm not aware of an owner's group. I am aware of at least 10-15
completions (probably more but it is hard to say).

A few completions appeared in Kitplanes.

http://user.tninet.se/~trz012v/windrose/WindroseII99.htm

http://user.tninet.se/~trz012v/windrose/Rene.htm

http://user.tninet.se/~trz012v/windrose/Roman.htm

If Mat Redsell hasn't already e-mailed you, expect to hear nothing but
negatives from him. He refurbished one, lost control while flying it
and bailed. Rather than admit that he might have had the CG too far
aft, he never measured it and he is on the small side, he prefers to
badmouth the design.

You should know that there have been 2 deaths, both were the classic
engine quit upon launch and try to slowly turn and make it back to the
runway. Not a good idea, especially at low altitude. They both spun
in. But then there have been at least 10 such incidents in Moni's
(very underpowered) and even the Russia AC5M has already had 2 launch
accidents. One resulted in very serious injury. The other destroyed
the glider, pilot ok thankfully. I think the moral here is
motorgliders can demand extra attention, especially during self launch
and if power is lost. One must "fly the glider" (i.e., don't lose
airspeed if the motor quits!) at all times.

Irv Culver, the chief designer of Windrose, was a highly respected
aeronautical engineer that worked at Lockheed's "Skunkworks". Jim
Maupin was also heavily involved. Both were also responsible for the
Woodstock and Carbon Dragon. Either of these guys had probably
forgotten more than Redsell will ever know about gliders. I believe
that Redsell was personally responsible for the Maupin family stopping
to make the plans for all 3 gliders (Woodstock, Windrose, Carbon
Dragon) available to the public. A real loss...

Regards,

-Doug

Marske Flying Wings

October 15th 03, 02:23 PM

I did not refurbish a Windrose.. I purchased a very incomplete one that I
completed in about four years work. The story of the building and flying is
on a web site

http://www.continuo.com/windrose/windrose.htm.

One should read the site and made their own minds up. I felt there was a lot
of potential with this aircraft but it had not been thoroughly tested
enough before it was released to the public. The plans also need updating as
carbon rovings do not make a predictible spar.

I suggested very strongly that Janice Maupin sell the plans with the
understanding that it was a concept that needed refining.

The main prolbem is that the aircraft was never thoroughly tested. There is
one main problem. The all flying tail can stall as it did twice for me in a
dive. The first time I was able to recover: the second I could not recover
and had to bail out.

The other very severe problem was the easily stalled wing tips which for a
motor-glider is not very good. It also had difficult handling
characteristics in circling that I was never able to remedy.

The construction is also questionable with the inboard ailersons. They do
work but contribute to the wing stalling and should be further investigated.

I do know my aerodynamics well and have been a test pilot in the development
of the Flying Wings of Jim Marske. I also modify the aircraft I fly and
work extensively in carbon and fiberglass. My work can be seen on the Marske
Web site. I am also an instructor.

I am helping Jim Marske in the upcoming Spar workshop held on November
22-23, 2003.

As unpopular as I am still feel that I gave a good assessment of the
windrose and shall continue to convince designers to have their creations
thoroughly tested.

-mat
--
Marske Flying Wings
http://www.continuo.com/marske

Doug Hoffman

October 20th 03, 01:30 AM

"Marske Flying Wings" > wrote in message >...
[snip]
> As unpopular as I am still feel that I gave a good assessment of the
> windrose and shall continue to convince designers to have their creations
> thoroughly tested.

What is your opinion of the Carbon Dragon and Woodstock?

Marske Flying Wings

October 21st 03, 02:58 PM

I do not have any building experience with the Woodstock or Carbon dragon
but I can make some general comments.

The use of wood in a glider is not really recommended any longer, nor is the
combination of wood and fiberglass. Ineveitably the wood and fiberglass tend
to separate. It is better to use an all fiberglass structure and I even
avoid the use of foam.

Spars constructed with carbon rovings are unpredictable and tests have shown
that compression and tension readings are very low ( 30.000- 60,000 psi)
whereas using a carbon rod will give a predictable 300,000 psi.

I have seen the prototype carbon dragon and the one built by Steve Arnt.
Steve's magic drag was much modified and he had tested his carbon rod spar.
He had done his research well. The use of carbon rovings is again not
predictible and the combination with wood I do not recomend. I suggest that
it would be better to vacuum mold all the parts from carbon cloth. Again I
have not seen any flight reports on the carbon dragon as to stability, spins
and general handling. Much development is now needed in this design but for
the time was a brilliant step forward in light wingloading soaring.

And as to your comment about the CG location on my windrose... I built it on
a weigh scale to make sure the CG came out at the correct position. I had
flown it to begin with in a slightly forward position and gradually moved it
back as needed. I have done a lot of work establishing the CG postion for
the Marske Pioneers and Monarchs .The designer has some idea of where the CG
belongs but each aircarft is different and the Cg refinement is then done by
a qualfied test pilot. The windrose was easily tip stalled and the all
flying tail could be stalled..... and that remains its' worst features.

-mat
--
Marske Flying Wings
http://www.continuo.com/marske

Bert Willing

October 21st 03, 04:12 PM

Now that is something interesting.

Doesn't seem to have crossed the big pond so far...

--
Bert Willing

ASW20 "TW"

"Marske Flying Wings" > a écrit dans le message de
...
> The use of wood in a glider is not really recommended any longer, nor is
the
> combination of wood and fiberglass. Ineveitably the wood and fiberglass
tend
> to separate. It is better to use an all fiberglass structure and I even
> avoid the use of foam.
>
> Spars constructed with carbon rovings are unpredictable and tests have
shown
> that compression and tension readings are very low ( 30.000- 60,000 psi)
> whereas using a carbon rod will give a predictable 300,000 psi.
>

Doug Hoffman

October 22nd 03, 10:51 AM

"Marske Flying Wings" > wrote in message >...

> Spars constructed with carbon rovings are unpredictable and tests have shown
> that compression and tension readings are very low ( 30.000- 60,000 psi)
> whereas using a carbon rod will give a predictable 300,000 psi.

Jim Marske shows carbon rovings to have 120,000 psi tensile
strength in his website. Not the numbers you show. ??

Mat, please cite for me the instances where the carbon roving
spar caps have failed. Either during proof loading or in flight.
Windrose or Carbon Dragon.

I will not question that the pultruded carbon
rods are an excellent building material. Had the stuff been
available when Culver and Maupin were designing they may even
have used them instead. But you can't say that the carbon
rovings are dangerous (you say/imply this in your website and imply it
in your postings).

Scott Correa

October 22nd 03, 02:50 PM

"Doug Hoffman" > wrote in message
m...
> "Marske Flying Wings" > wrote in message
>...
>
> > Spars constructed with carbon rovings are unpredictable and tests have
shown
> > that compression and tension readings are very low ( 30.000- 60,000 psi)
> > whereas using a carbon rod will give a predictable 300,000 psi.
>
> Jim Marske shows carbon rovings to have 120,000 psi tensile
> strength in his website. Not the numbers you show. ??
>
> Mat, please cite for me the instances where the carbon roving
> spar caps have failed. Either during proof loading or in flight.
> Windrose or Carbon Dragon.
>
> I will not question that the pultruded carbon
> rods are an excellent building material. Had the stuff been
> available when Culver and Maupin were designing they may even
> have used them instead. But you can't say that the carbon
> rovings are dangerous (you say/imply this in your website and imply it
> in your postings).

Boys Boys Boys......

Everybody knows that the compressive value for carbon fiber is about zilch.
The compressive values given are really a measure of the interlaminar shear
values
of the matrix they are suspended in.
Mat has chosen to further confuse the issue by pointing out that earlier
construction
methods using different lower modulus matrixes and dry unimpregnated
rovings with lower
fiber content develop lower mechanical
properties..............................

No ****, I would have never figured that out on my own.........

I am growing tired of this. If wood and f/glass are unsuitable for gliders,
stop test flying
unsafe Pioneers and Monarchs and quit selling plans...... But that would be
the wrong
thing to do because wood and f/glass are safe when properly built and
maintained.
The same must be said for carbon and kevlar. Dry rovings are suitable for
use in
spars as long as you use enough of it. It may be LESS EFFICIENT than
pultruded
rods, but it is not inherently unsafe. You also completely gloss over the
fact that compressive
spar failures are damn near universally collum buckling as opposed to
classic compressive failures.

Mat, you should really email your stuff to yourself and read it before you
send it to the world.
We've talked on the phone, your a smart guy and it is fairly obvious to me
that you are having
difficulty conveying your thoughts with the written word.

Doug.............. Did ya hear the one about wrestling with a pig?????

Scott.

Marske Flying Wings

October 22nd 03, 02:53 PM

Jim and I are conducting a Spar workshop on november 22-23, 2003 in Marion
OH.

Carbon Rovings are a very poor spar material since you cannot pull all of
the strands straight and through testing it was found to have a wide
variance in tension and compression. Compression being the worst case which
is about 40,000 to 80,000 psi... one may get to 120,000 psi in tension but
this is highly unreliable so you must degrade the enitre layup ..... but
just what do you degrade it to... it depends on how well the person laid it
up. With the Tests that Jim did, they where extremely careful and where
professional fabricators in fiberglass and those results where very
discouraging.. With carbon rods there is no guessing as to what numbers you
are dealing with. Also the process has been thoroughly tested.

The other problem is that with the windrose construction you are directed to
drill through the carbon. This is an absolute mistake!! This is dangerous.

If you are asking an amateur builder to construct the spar with roving you
have a situation where the result is highly unpedictible and then drilling
through the spar increases the danger that the spar could fail.

As for instances of actual breaking in the air..... I'd rather build it
correctly first and not have to site facts of dead pilots and broken wings.
See our testing of the carbon Monarch spar on our web site for example.

All of the Maupin plans need upgrading to deal with modern practices and
show that indeed the aircraft have been throughly tested. From what I have
seen the Maupin/ Culver designs where never thoroughly tested and with the
15 meter windrose was never even built by the designers.

Jim Maupins designs were wonderful concepts and should be studied with that
in mind but they are not a refined aricraft as they exist at present.

Having siad all of that we in north america do need some brave designers to
challenge the dominance of the German ships. It takes a lot of money, guts,
research and hard work. and do not expect much support from your fellow
soaring pilots! That Jim Maupin got outside the normal glider design was
very welcome... that he tried new concepts was great...that he opened up the
light sailplane was terriffic..... but we need dedicated people to continue
these ventures. It will not be profitable... and plans should not be sold
unless you have a craft that has been thoroughly tested. However people can
donate to the cause and be an active part of a development.

-mat
--
Marske Flying Wings
http://www.continuo.com/marske

Bob Kuykendall

October 22nd 03, 05:04 PM

Earlier, (Doug Hoffman) wrote:

> Jim Marske shows carbon rovings to have 120,000 psi tensile
> strength in his website. Not the numbers you show. ??

Actually, that's the Web site that Mat maintains for Jim Marske. So
Mat does know exactly what's on it.

But on-topic, what's really at issue is not the tensile strength, but
the compression strength.

The way I understand the issue from personal conversations with Jim
Marske, hand-laid carbon rovings often drastically under-perform their
predicted values in compressive strength. The problem is that it is
very difficult to achieve the proper fiber alignment and resin content
and properties under hand-layup conditions. The result is compressive
strength (the kind you usually need in an upper spar cap) in the
neighborhood of only 40 ksi or 60 ksi. Jim says he did coupon tests to
validate these numbers, and I certainly believe him.

In comparison, the Graphlite rods and strips are amazing, with tensile
strengths of something like 320 ksi and compressive of about 280 ksi.
They achieve these very high values using a pultrusion process in
which the perfect fiber/resion ratio is achieved, and in which the
fibers are perfectly aligned, and in which the fiber/resin matrix is
heated and compressed to achieve the best possible resin properties.

The only area in which the Graphlite does not vastly outperform
hand-laid carbon is in stiffness. The stuff is about 20% stiffer than
hand-laid, which is great but not incredible. In glider design, much
of the structure is bounded by stiffness and not strength. In
stiffness-bound applications, the Graphlite products will give you a
20% weight reduction over hand-laid; but as a side-benefit they give
you about 600% greater ultimate strength.

I used the Graphlite rods according to Jim Marske's design
methodologies in the HP-24 wing spar, and what I got was a wing spar
for a 9-meter wing panel (half of the 18-meter total span) that weighs
16.5 lbs (about 20 lbs after the spar butt reinforcements are added).

Thanks, and best regards to all

Bob K.
http://www.hpaircraft.com/hp-24

Scott Correa

October 22nd 03, 07:40 PM

"Bob Kuykendall" > wrote in message
> But on-topic, what's really at issue is not the tensile strength, but
> the compression strength.
>
> The way I understand the issue from personal conversations with Jim
> Marske, hand-laid carbon rovings often drastically under-perform their
> predicted values in compressive strength. The problem is that it is
> very difficult to achieve the proper fiber alignment and resin content
> and properties under hand-layup conditions. The result is compressive
> strength (the kind you usually need in an upper spar cap) in the
> neighborhood of only 40 ksi or 60 ksi. Jim says he did coupon tests to
> validate these numbers, and I certainly believe him.
>

Excellent stuff Bob.....
I also believe Jims numbers.........
Compressive strength is the upper spar cap limiting constraint.
Rovings or tow, are admittedly difficult to use, BUT can be used
successfully. Personally, I find that Unitape cures many of Mats
concerns about orientation and resin content. In fact it is so commonly
used that free tow is basically off the market. 20 some odd years ago
when carbon was expensive,new,untested, all you could get was dry tow.
Bunches better than not having it, but definately not state of the art
today.
Todays woven goods are vastly superior to the old stuff. I hesitate to
condemn its use in spars. It might be a bit less efficient than rods but
definately
usable in todays structures. Especially by the workman at home.

NOW lets also get down to brass tacks and admit to each other that the mode
1
failure of upper spar caps is BENDING caused by a collum buckling. When
this
occurs the substructure supporting the spar caps deflects and the cap fails
in bending.
A good example is when the shear web ruptures as the bending loads go up and
the
spar cap can't absorb the local bending load. The failure looks different
than a
compressive failure (because it is) inasmuch as it looks like a snapped
pencil.

Scott.

Marske Flying Wings

October 22nd 03, 09:09 PM

To add to the discussion of Carbon in use with spars.

One of the important elements that should not be forgotten is the
deflection. With Carbon rods you can accurately predict the deflection which
I believe is very important in glider wings. I have produced a spreadsheet
that will predict the amount of rods needed and predict the deflection. A
good deflection is about 10 to 12 " per G and with hand laid up rovings you
may overcompensate to account for the poor quality of rovings and produce a
very stiff wing.

And incidently I own and maintain the site and work in partnership with Jim.
-mat
--
Marske Flying Wings
http://www.continuo.com/marske

Mike Borgelt

October 22nd 03, 10:17 PM

On Tue, 21 Oct 2003 17:30:24 +0000, Robert Ehrlich
> wrote:

>Marske Flying Wings wrote:
>> ...
>> The use of wood in a glider is not really recommended any longer, nor is the
>> combination of wood and fiberglass. Ineveitably the wood and fiberglass tend
>> to separate. It is better to use an all fiberglass structure and I even
>> avoid the use of foam.
>> ...
>
>However a lot of fiberglass gliders are using wood (mostly plywood)
>for holding various elements of the linkages from stick/spoilers lever
>to the control surfaces they actuates. I had just a look inside one of
>our Pegases where the seat pan has been removed for its annual, and it
>is made this way. IIRC this fuselage is a copy of the ASW20, never heard
>of separation of wood from fiberglass, neither in Pegases nor in ASW20's
>and there is a lot of them flying since a lot of time.

Wood inside fibreglass can be a problem for repairs. The wood will
shatter inside the fiberglass and you end up removing good glass to
repair the wood.
I was told this by Harry Schneider (glider designer, manufacturer and
repairer) at Gawler about 30 years ago and subsequently saw an example
of what he was talking about.

Mike Borgelt

Doug Hoffman

October 23rd 03, 12:18 AM

(Bob Kuykendall) wrote in message >...
> In comparison, the Graphlite rods and strips are amazing, with tensile
> strengths of something like 320 ksi and compressive of about 280 ksi.
> They achieve these very high values using a pultrusion process in
> which the perfect fiber/resion ratio is achieved, and in which the
> fibers are perfectly aligned, and in which the fiber/resin matrix is
> heated and compressed to achieve the best possible resin properties.

Bob,

With all due respect I think you missed my point. I am not saying
"don't use the rods".

I said:
'I will not question that the pultruded carbon
rods are an excellent building material. Had the stuff been
available when Culver and Maupin were designing they may even
have used them instead.'

My point was that materials other than the rods can still be safely
used (providing they are used properly, etc., etc.). There is no
reason for Mat to be condemning the perfectly legitimate use of the
carbon rovings as used in the Windrose and Carbon Dragon. Guess what,
the Windrose 13 meter doesn't even use carbon. It uses fiberglass
rovings.

Also, when using the rovings as specified for the Windrose I or II or
CD one avoids the complexity and possible source of error of having to
design and build an additional structure to tie the main spar
pins/bolts to the carbon rods. One needs only to drill bolt holes
straight through the roving layup. Simple, easy. Which was one of
the design criteria for the glider.

Again, I'm not slamming the rods. I think they are great. I just
think Redsell doesn't know what he is talking about when he says the
rovings cannot be safely used and other things he's said that I won't
get into. Note that he did not produce the evidence that I asked for,
that is: even one instance of roving spar cap failure either through
proof loading or flight loads. He didn't because he can't. Culver
was not incompetent. Irv Culver is not able to defend himself from
the likes of Redsell because he is dead. Especially given that,
Redsell has taken a lot of cheap shots, in my opinion.

-Doug

Marske Flying Wings

October 23rd 03, 02:40 PM

Doug hoffman wrote:
<My point was that materials other than the rods can still be safely
used (providing they are used properly, etc., etc.). There is no
reason for Mat to be condemning the perfectly legitimate use of the
carbon rovings as used in the Windrose and Carbon Dragon. Guess what,
the Windrose 13 meter doesn't even use carbon. It uses fiberglass
rovings.>

The point I am making is that there is no way you can honestly compute the
strength you have using carbon rovings with hand layup especially for
someone who has never done it before. Even a fiberglass pultrusion would
have been better as Jim used in the early Monarchs. The other problems is
that you cannot compute the deflection at the wing tips which should be
about 10-12 ". So if an amateur is building the wings for the first time he
could easily mess it up by not being consistent in the pulling of the carbon
or fiberglass tow. I have found that there is no underestimating the bad
buidling practices of some homebuilders. I have had to correct a number of
homebuilts!

Doug hoffman wrote:
<Also, when using the rovings as specified for the Windrose I or II or
CD one avoids the complexity and possible source of error of having to
design and build an additional structure to tie the main spar
pins/bolts to the carbon rods. One needs only to drill bolt holes
straight through the roving layup. Simple, easy. Which was one of
the design criteria for the glider.>

Once you drill through the carbon you have little tensile strength left at
that point since you are relying on the fiber to give you the strength. The
carbon should be properly bonded to a well engineered fiberglass block ,and
that is what you drill. Never drill through the carbon!!!!

Remember also that you cannot put iron and carbon together... galvanic
action corrodes the bolt.

Rather than present those wings that have broken in the air, a better method
is to see the results of the testing of the Marske Designed spar in the
Genesis that went to 18 G's before the fitting broke on the test stand. Jim
had tested each of the componet parts proving that this method would not
come apart after many years of use. And this was all predictible. There are
no studies done on the longevity of the windrose style of spar.

So in my estimation using rovings can be dangerous for the first time
builder and especially so if you drill through it. I do realize there are
still a number of glider manufactureres building spars with carbon rovings
but gradually they are changing to accept Jim Marske's proven Carbon rod
spar. See the article in the SHA newletter from the Silent Glider
manufactuere.

--
Marske Flying Wings
http://www.continuo.com/marske

Scott Correa

October 23rd 03, 06:03 PM

"Marske Flying Wings" > wrote in message
...
1) The point I am making is that there is no way you can honestly compute
the
strength you have using carbon rovings with hand layup especially for
someone who has never done it before.
2) The other problems is that you cannot compute the deflection at the wing
tips which should be about 10-12 ".
3) I have found that there is no underestimating the bad
buidling practices of some homebuilders. I have had to correct a
number of
homebuilts!
4) Once you drill through the carbon you have little tensile strength left
at
that point since you are relying on the fiber to give you the
strength. The
carbon should be properly bonded to a well engineered fiberglass block
,and
that is what you drill. Never drill through the carbon!!!!
5) Remember also that you cannot put iron and carbon together... galvanic
action corrodes the bolt.

Good Morning Mat.

1) You can certianly do it. It is accomplished in the same manner that all
other materials
are checked. You just have to decide on a value to use. You say you have
tested and
shown values as low as 30KSI. Cool, use that and move on........

2) Your wind bending allowables may be 10 to 12 inches, but that is a
subjective opinion.
Many all glass birds deflect more with no ill effects. Yours is a
subjective opinion
presented as a fact.........

3) Agreed, But these clowns would be the same fools who couldn' glue in the
rods properly
either, so I'll forget about misassembly. Your DAR or Tech Councellor
will stop this from
being a problem.

4) The loss of tensile strength is very dependant on the reduction in
laminate cross section. Unless
you have the particular layup schedule in front of you, you can't make
an informed decision on the
reduction in tensile strength. If the laminate gets thicker or wider,
all bets are off. If the laminate
is the same in cross section at the hole location as it is outboard of
there, you still need to run the
numbers to see if the remaining cross section meets the design loads.
Again, lacking that data,
neither of us can make an informed decision. You are correct that you
will experience a local
reduction in tensile strength, but it may still very well reach the
design limits and be of no consequence.

5) This is a narrowminded statement. You would be correct if you put the
fasteners in "dry", but only
a fool would do that. Many steel and titanium fasteners are installed
through carbon
panels on Boeing and MDC jetliners. I have installed them. The trick
is to install them "wet" with
an approved sealant to provide the barrier you need. Entirely doable
and cost effective. Proclaiming
that you can't do it is in my mind incorrect, but we can disagree on
how you present the facts on this one.

Back on point. There is no reason you can't use hand layed up carbon
successfully. Yeah it requires care,
but so does riveting , welding, dope and fabric and all the other processes
involved in amatuer constructed
aircraft. Some people find it easy to work composites well, some are very
challenged. Blanket statements saying it
is unsafe to do so is in my mind bull****...........

Scott Correa

Marske Flying Wings

October 23rd 03, 10:30 PM

Scott Correa,

Yes those things can all be done and at one time where probably accepted as
normal practice.... but we have better methods and materials today so lets
use them. Jim Marske's Spar design is the best design I have seen so lets
give him credit for such good work and encourage others to use this.

As for dangerous, that is for each of us to decide: but for me I want the
best technology, methods and proven methods with predictable results and
that is exactly what the Windrose lacks in its present state....there was no
mention in the plans of coating anything with epoxy and the carbon tow was
not increased at the point where the bolts went through.

Update the Windrose plans, do a lot of test flying... that will go a long
way to remedy this design.

-mat
--
Marske Flying Wings
http://www.continuo.com/marske

Doug Hoffman

October 24th 03, 09:54 PM

Mat Redsell Writes:
[snip]
>
> As for dangerous, that is for each of us to decide: but for me I want the
> best technology, methods and proven methods with predictable results and
> that is exactly what the Windrose lacks in its present state....there was no
> mention in the plans of coating anything with epoxy and the carbon tow was
> not increased at the point where the bolts went through.

Umm, page 8 of Jim Maupin's instructions. Third paragraph: "If everything
checks out, drill the spar stubs for the 5/16" bolts, and bolt in place. I
recommend using lots of epoxy in the bolt holes and on the nuts."

> and the carbon tow was
> not increased at the point where the bolts went through.

Oh please. Did you really build one of these? I'm not even going
to bother rolling open the plans to give the measurements. The
hot-wired slot in the foam, for the spar caps, is a *lot* bigger
at the spar root than anywhere else.

I am tiring of this, Mat.

What kind of technical education did you say you received? It must
be impressive for you to berate Irv Culver's calculations as you are
doing.

Marske Flying Wings

October 28th 03, 02:41 AM

Doug,
The larger space you refer to at root of the wing spar is quite normal. One
tapers the upper and lower spar caps according to the forces you are dealing
with. Unfortunately the Windrose drills through the carbon tow at the root
section effectively reducing the thickness at this point. It would have been
far better to have the carbon tow go around the bolts... or as in the Marske
spar design have the loads transferred to fiberglass blocks without breaking
the carbon tow.

If you look at the rather skimpy poorly written manual it does not mention
the galvanic action that could take place. it would have been good for
first time builders to realize the possibility of galvanic action on the
bolts. I may have missed your reference to the epoxy but I would have
thought that the resons should have been well explained in the plans.

At any rate lets drop this discussion and let the would be builders of the
windrose do their own research.

And anyone wanting windrose plans can have mine for the postage.

I do not recommend building this glider, but it does make for an interesting
study in inboard ailerons that needs a lot of refinement since the Windrose
has not been thoroughly tested nor updated.

The use of the full span elevons of gliders such as the Apis are a lot more
effective and the Apis has been designed by those who are fluent in
aircraft design, thoroughly tested and flown by many.

Those interested in the Windrose should research it carefully on the
internet and see it fly. This is not and aircraft for the low time amateur
builder or low time flyer and should be treated as an interesting
experiment that is not yet complete.

-mat
--
Marske Flying Wings
http://www.continuo.com/marske

Doug Hoffman

October 28th 03, 11:22 PM

Mat Redsell writes:

>Unfortunately the Windrose
>drills through the carbon tow at the root section effectively
>reducing the thickness at this point.

Drilling a hole through something reduces the thickness at
that point? Wow. Who would have ever figured that out?

>It would have been far better to have the carbon tow go around
>the bolts...

I really don't follow at all what you are saying here. It
sounds goofy and dangerous. You never answered my question
about your technical education.

>or as in the Marske spar design have the loads transferred to
>fiberglass blocks without breaking the carbon tow.

Then you drill holes in the fiberglass block. Using your
logic, then you have just weakened the fiberglass block
rendering it useless. That's *your* logic, Mat. But it
doesn't work that way, does it? It also doesn't work
that way for the carbon tow build-up. Culver designed it
to be thick enough to account for the holes that he knew
were to be drilled in it. Sheesh, I thought Scott
finally made that point clear to you.

>And anyone wanting windrose plans can have mine for the postage.

That is not ethical Mat. It clearly states on the plans that
only *one* glider is to be built from that set of plans. You
could build more but you should send $225 to the Maupins for each
glider, in all fairness. Would you like it if others freely
passed around Pioneer II plans? I see you are now selling
the Pioneer II plans for $248.

By the way. I also see from your website that the Pioneer IId
kit that you sell is using wood spars:

"SPAR: All wood, "I" beam construction for a high strength to
weight ratio. Spar caps are aircraft Sitka Spruce and web is 1/2"
marine or aircraft grade plywood."

You said earlier:

>but for me I want the best technology, methods and proven methods
>with predictable results [in-context implication was one should now
always use carbon rods]

What? NO CARBON RODS in the Pioneer II? Hey man, you don't walk
the talk. I'm just curious to know how you build those wood
spars without drilling holes in the wood...