Production rates?

I ve got only the user's manual, more it's in Polish only:

http://www.szybowce.enter.net.pl/ins...ior/junior.pdf

What exact info on maitenance You need?

I wanted to have a look at the structural repair sections of the manual to
study the composite layups and the way that the structure is put together. I
have a very good understanding of composite manufacturing processes and I
just wanted to think through what tooling was required and do some estimates
on the times required to manufacture the parts.


However, the shorp production process has been achieved so far only by the
SZD and the Grob factories.

Do we know anything about how long Grob took to make a Twin Astir or a


The production process of Junior comprised od TWO DAYS in a SINGLE SHIFT
system, so one day in a two shifts, I have checked this.

OK ... was this just for the composite airframe or did the glider roll out
the door at the end of the two days with canopy, control systems, landing
gear, instruments etc all fitted ?.


correctly) and using the molds which didn't need the pressure forced
forming
of the fuselage in the molds (well I am not sure if I had translated it
properly into English).

I think what you are trying to say is that they did not need vacuum bagging
? Correct ?

Improvements for this? The capital expenditure for any of it never pays
off,
so just forget about it.

Not necessarilly ... no one said you had to invest money to get access to
improved production equipment. Perhaps the production of parts needs to be
subcontracted to someone who has already invested the money in the equipment
for other reasons.


The main amount of manpower is needed AFTER the thing is demoulded -
finishing is quite a job, even for professionals.

Yep you are right !!

Depends on the resin which is used - the L20 resin for example must be cured
at high temperature (around 55-60 deg C) for some hours (typically
overnight) in order to obtain the final strength of the resin and to push
the glass transition temperature to above 54 deg C.
Easy to do, though: Make a shelter of thick foam plates where the mould just
fits in, put a temperature-controlled hot air fan in it and switch it on.

--
Bert Willing

ASW20 "TW"


"smjmitchell" a écrit dans le message de
news: ...
Is hot curing common in glider factories ? Are these using ovens, heater
blankets or perhaps heated moulds ?



"Bert Willing" wrote in
message ...
You have two moulds for each wing, and two moulds for the fuselage (plus
two
for the stabilizers). All can be layed up in parallel (you need three men
less than 8 hours on one mould), that takes one day. Spraying of the gel
coat is done the night before. Glueing them together and hot-curing them
takes another day.

However, cost is counted in manhours, not in days. The time needed for
layup
is about the same for carbon and for glass (some experience needed,
though)
and the planiform of the wing has no influence whatsoever.

Improvements for this? The capital expenditure for any of it never pays
off,
so just forget about it.

The main amount of manpower is needed AFTER the thing is demoulded -
finishing is quite a job, even for professionals. And that has been the
reason why Grob gliders were very reasonably priced at their time - they
just had less finish.

--
Bert Willing

ASW20 "TW"


"smjmitchell" a écrit dans le message de
news: ...
As far as building a Junior in two days, maybe, but I'd still think in
terms of 680 man hours as the substantial difference is fixed gear vs
retract. Two days is a meaningless concept without knowing whether
30-40
people were involved for 8 or 12 hour shifts.


I suspect that one Junior emerged from the factory every 2 days but
surely
they must have spent longer on the line than 2 days. If for instance
you
have 5 stations on the line and each airframe spent 2 days at each
station
that is a total of 10 days on the line. Now if 3 guys worked in each
station
with two shifts that is a total of 5 (stations) x 2 (days) x 3 (# guys)
x
8
(shift hours) x 2 (# shifts) = 480 hours. This seems achievable for a
simple
glider. I just cannot see how a sailplane of conventional construction
could
be made in an elapsed time of only 2 days when cure time etc is allowed
for.

If indead it is true that the Junior was made in 2 days with two shifts
then
this deserves careful study. Does anyone have a PDF copy of the Junior
maintenance manual ????

Janusz ... do you have any more info on this ????


Frank,

Filament winding is one method that's been shown to work, at least by
Rutan.

There is a lot of conflicting information around on exactly how Rutan
builds
his airframes. Some people say thay he uses a tape layer and others
filament
winding. How confident are you in your information that he filament
winds
?
If filament winding is used (and I believe this is probably the case)
then
I
am assuming he uses prepreg tow ???? Or is he using a wet layup with
one
of
the resins that has an extraordinarly long pot life (1-2 days) (there
are
some excellent wet layup resins available now that are meant for this
sort
of application).


However, there are limitations to the process that might make it
impractical
for most glider production.

Such as ????


Even then, the pod took something like 7 hours
to wind and the fuselage was 24 hours of continuous processing.

Are you refering to the Boomerang ????

It sounds like you have some knowledge of the Rutan processes ... can
you
outline the process. What does he use for the plug to wind around ???
What
sort of winding machine - a simple two axis thing or something more
complex
?? What sort of tow (12k ... 24k etc) ??? Does he wind a grid
arrangement
of stiffeners on the inside of the fuselage ??? (it appears so from
some
photo's you see) And the really big question .... how does he get the
outside smooth (perhaps this is one of the limitations you mention
??? -
perhaps this involved a lot of hand filling and sanding ?). What is the
cure
... oven ??? room temperature ??? What are the thickesses of the
skins
?
What is the typical winding angle ?

Yes a post cure is normal for any composite structure. A glider or any
composite aircraft should be aiming for a Tg of at least 54 + 27 = 81 deg C.

54 deg C comes from NASA CP 2036 / CR 3290 per the JAR VLA ACJ's (white
surface on a hot day).

27 deg C (50 deg F) is the standard margin between Tg and the service
temperature that is recommended in MIL-HDBK-17 and accepted by
certificatioon authorities around the world.

Generally I would post cure at a higher temperature than 55-60 deg C but one
needs to be careful of the core material and this varies depending on the
resin. Often you can get the resin manufacturers to run Tg tests for you to
provide advice on the exact temperature and cycle to use for a particular
application.


I guess what I was really getting at though was whether manufacturers are
using heat to speed up the initial cure so they don't have to stand around
waiting for the room temperature cure. I wasn't really refering to post
cure.







"Bert Willing" wrote in
message ...
Depends on the resin which is used - the L20 resin for example must be
cured
at high temperature (around 55-60 deg C) for some hours (typically
overnight) in order to obtain the final strength of the resin and to push
the glass transition temperature to above 54 deg C.
Easy to do, though: Make a shelter of thick foam plates where the mould
just
fits in, put a temperature-controlled hot air fan in it and switch it on.

--
Bert Willing

ASW20 "TW"


"smjmitchell" a écrit dans le message de
news: ...
Is hot curing common in glider factories ? Are these using ovens,
heater
blankets or perhaps heated moulds ?



"Bert Willing" wrote in
message ...
You have two moulds for each wing, and two moulds for the fuselage
(plus
two
for the stabilizers). All can be layed up in parallel (you need three
men
less than 8 hours on one mould), that takes one day. Spraying of the
gel
coat is done the night before. Glueing them together and hot-curing
them
takes another day.

However, cost is counted in manhours, not in days. The time needed for
layup
is about the same for carbon and for glass (some experience needed,
though)
and the planiform of the wing has no influence whatsoever.

Improvements for this? The capital expenditure for any of it never pays
off,
so just forget about it.

The main amount of manpower is needed AFTER the thing is demoulded -
finishing is quite a job, even for professionals. And that has been the
reason why Grob gliders were very reasonably priced at their time -
they
just had less finish.

--
Bert Willing

ASW20 "TW"


"smjmitchell" a écrit dans le message
de
news: ...
As far as building a Junior in two days, maybe, but I'd still think
in
terms of 680 man hours as the substantial difference is fixed gear
vs
retract. Two days is a meaningless concept without knowing whether
30-40
people were involved for 8 or 12 hour shifts.


I suspect that one Junior emerged from the factory every 2 days but
surely
they must have spent longer on the line than 2 days. If for instance
you
have 5 stations on the line and each airframe spent 2 days at each
station
that is a total of 10 days on the line. Now if 3 guys worked in each
station
with two shifts that is a total of 5 (stations) x 2 (days) x 3 (#
guys)
x
8
(shift hours) x 2 (# shifts) = 480 hours. This seems achievable for a
simple
glider. I just cannot see how a sailplane of conventional
construction
could
be made in an elapsed time of only 2 days when cure time etc is
allowed
for.

If indead it is true that the Junior was made in 2 days with two
shifts
then
this deserves careful study. Does anyone have a PDF copy of the
Junior
maintenance manual ????

Janusz ... do you have any more info on this ????


Frank,

Filament winding is one method that's been shown to work, at least
by
Rutan.

There is a lot of conflicting information around on exactly how Rutan
builds
his airframes. Some people say thay he uses a tape layer and others
filament
winding. How confident are you in your information that he filament
winds
?
If filament winding is used (and I believe this is probably the case)
then
I
am assuming he uses prepreg tow ???? Or is he using a wet layup with
one
of
the resins that has an extraordinarly long pot life (1-2 days) (there
are
some excellent wet layup resins available now that are meant for this
sort
of application).


However, there are limitations to the process that might make it
impractical
for most glider production.

Such as ????


Even then, the pod took something like 7 hours
to wind and the fuselage was 24 hours of continuous processing.

Are you refering to the Boomerang ????

It sounds like you have some knowledge of the Rutan processes ... can
you
outline the process. What does he use for the plug to wind around ???
What
sort of winding machine - a simple two axis thing or something more
complex
?? What sort of tow (12k ... 24k etc) ??? Does he wind a grid
arrangement
of stiffeners on the inside of the fuselage ??? (it appears so from
some
photo's you see) And the really big question .... how does he get
the
outside smooth (perhaps this is one of the limitations you mention
??? -
perhaps this involved a lot of hand filling and sanding ?). What is
the
cure
... oven ??? room temperature ??? What are the thickesses of the
skins
?
What is the typical winding angle ?

No, it's not done to speed up the curing. However, most resin employed
nowadays - especially for carbon fiber lay-up - do need a (post-) curing
treatment. The exact temperature is given by the resin manufacturer.

--
Bert Willing

ASW20 "TW"


"smjmitchell" a écrit dans le message de
news: ...
Yes a post cure is normal for any composite structure. A glider or any
composite aircraft should be aiming for a Tg of at least 54 + 27 = 81 deg
C.

54 deg C comes from NASA CP 2036 / CR 3290 per the JAR VLA ACJ's (white
surface on a hot day).

27 deg C (50 deg F) is the standard margin between Tg and the service
temperature that is recommended in MIL-HDBK-17 and accepted by
certificatioon authorities around the world.

Generally I would post cure at a higher temperature than 55-60 deg C but
one
needs to be careful of the core material and this varies depending on the
resin. Often you can get the resin manufacturers to run Tg tests for you
to
provide advice on the exact temperature and cycle to use for a particular
application.


I guess what I was really getting at though was whether manufacturers are
using heat to speed up the initial cure so they don't have to stand around
waiting for the room temperature cure. I wasn't really refering to post
cure.







"Bert Willing" wrote in
message ...
Depends on the resin which is used - the L20 resin for example must be
cured
at high temperature (around 55-60 deg C) for some hours (typically
overnight) in order to obtain the final strength of the resin and to push
the glass transition temperature to above 54 deg C.
Easy to do, though: Make a shelter of thick foam plates where the mould
just
fits in, put a temperature-controlled hot air fan in it and switch it on.

--
Bert Willing

ASW20 "TW"


"smjmitchell" a écrit dans le message de
news: ...
Is hot curing common in glider factories ? Are these using ovens,
heater
blankets or perhaps heated moulds ?



"Bert Willing" wrote in
message ...
You have two moulds for each wing, and two moulds for the fuselage
(plus
two
for the stabilizers). All can be layed up in parallel (you need three
men
less than 8 hours on one mould), that takes one day. Spraying of the
gel
coat is done the night before. Glueing them together and hot-curing
them
takes another day.

However, cost is counted in manhours, not in days. The time needed for
layup
is about the same for carbon and for glass (some experience needed,
though)
and the planiform of the wing has no influence whatsoever.

Improvements for this? The capital expenditure for any of it never
pays
off,
so just forget about it.

The main amount of manpower is needed AFTER the thing is demoulded -
finishing is quite a job, even for professionals. And that has been
the
reason why Grob gliders were very reasonably priced at their time -
they
just had less finish.

--
Bert Willing

ASW20 "TW"


"smjmitchell" a écrit dans le message
de
news: ...
As far as building a Junior in two days, maybe, but I'd still think
in
terms of 680 man hours as the substantial difference is fixed gear
vs
retract. Two days is a meaningless concept without knowing whether
30-40
people were involved for 8 or 12 hour shifts.


I suspect that one Junior emerged from the factory every 2 days but
surely
they must have spent longer on the line than 2 days. If for instance
you
have 5 stations on the line and each airframe spent 2 days at each
station
that is a total of 10 days on the line. Now if 3 guys worked in each
station
with two shifts that is a total of 5 (stations) x 2 (days) x 3 (#
guys)
x
8
(shift hours) x 2 (# shifts) = 480 hours. This seems achievable for
a
simple
glider. I just cannot see how a sailplane of conventional
construction
could
be made in an elapsed time of only 2 days when cure time etc is
allowed
for.

If indead it is true that the Junior was made in 2 days with two
shifts
then
this deserves careful study. Does anyone have a PDF copy of the
Junior
maintenance manual ????

Janusz ... do you have any more info on this ????


Frank,

Filament winding is one method that's been shown to work, at least
by
Rutan.

There is a lot of conflicting information around on exactly how
Rutan
builds
his airframes. Some people say thay he uses a tape layer and others
filament
winding. How confident are you in your information that he filament
winds
?
If filament winding is used (and I believe this is probably the
case)
then
I
am assuming he uses prepreg tow ???? Or is he using a wet layup
with
one
of
the resins that has an extraordinarly long pot life (1-2 days)
(there
are
some excellent wet layup resins available now that are meant for
this
sort
of application).


However, there are limitations to the process that might make it
impractical
for most glider production.

Such as ????


Even then, the pod took something like 7 hours
to wind and the fuselage was 24 hours of continuous processing.

Are you refering to the Boomerang ????

It sounds like you have some knowledge of the Rutan processes ...
can
you
outline the process. What does he use for the plug to wind around
???
What
sort of winding machine - a simple two axis thing or something more
complex
?? What sort of tow (12k ... 24k etc) ??? Does he wind a grid
arrangement
of stiffeners on the inside of the fuselage ??? (it appears so from
some
photo's you see) And the really big question .... how does he get
the
outside smooth (perhaps this is one of the limitations you mention
??? -
perhaps this involved a lot of hand filling and sanding ?). What is
the
cure
... oven ??? room temperature ??? What are the thickesses of the
skins
?
What is the typical winding angle ?

"Michael McNulty" wrote in message
news:9_Tod.157409$G15.55934@fed1read03...

"F.L. Whiteley" wrote in message
...

"smjmitchell" wrote in message
u...
Janusz,

Thanks for the information on build time hours. This is very useful
information. I think it illustrates that labour is where we need to
work
at
reducing the cost. One many year is approximately 2000 hrs .. actually
more
like 1700-1800 when holidays etc are considered. So 1400 hrs is a lot.
snip


Steve

Carbon layup, complex curves, flaperons, sparless construction(?), and
finishing work on the SZD-55 and certainly the Diana will take longer
than

The SZD-55 has no carbon; it is all fiberglass. It has conventional wing
spars. It does not have flaperons or even flaps.

Oops on that, thinking 56 which is of course Diana. I guess they spent the
extra time squeeging out the resin in the 55;^) It is a more complex build
than the 48, but that's a huge difference.

Frank

"smjmitchell" wrote in message
u...
Improvements for this? The capital expenditure for any of it never pays
off,
so just forget about it.

Not necessarilly ... no one said you had to invest money to get access to
improved production equipment. Perhaps the production of parts needs to be
subcontracted to someone who has already invested the money in the
equipment
for other reasons.

US labor for those types of machines is running $35-$45/hour. Then there's
material cost, machine costs, and profit. Even the simply constructed high
production rate composite cylinders remain very expensive. I think it's a
great idea conceptually, but prohibitively expensive practice. Aircraft fit
and finish at any level is very hands on.

Frank Whiteley

"Janusz Kesik" wrote in message
...

U¿ytkownik "smjmitchell" napisa³ w
wiadomo¶ci u...
As far as building a Junior in two days, maybe, but I'd still think in
terms of 680 man hours as the substantial difference is fixed gear vs
retract. Two days is a meaningless concept without knowing whether
30-40
people were involved for 8 or 12 hour shifts.


I suspect that one Junior emerged from the factory every 2 days but
surely
they must have spent longer on the line than 2 days. If for instance you
have 5 stations on the line and each airframe spent 2 days at each
station
that is a total of 10 days on the line. Now if 3 guys worked in each
station
with two shifts that is a total of 5 (stations) x 2 (days) x 3 (# guys)
x
8
(shift hours) x 2 (# shifts) = 480 hours. This seems achievable for a
simple
glider. I just cannot see how a sailplane of conventional construction
could
be made in an elapsed time of only 2 days when cure time etc is allowed
for.

If indead it is true that the Junior was made in 2 days with two shifts
then
this deserves careful study. Does anyone have a PDF copy of the Junior
maintenance manual ????

Janusz ... do you have any more info on this ????

I ve got only the user's manual, more it's in Polish only:

http://www.szybowce.enter.net.pl/ins...ior/junior.pdf

What exact info on maitenance You need? A total life of Junior is now 9000
or 12000hrs if I remember correctly, the mid-inspection interval is
1000hrs.

However, the shorp production process has been achieved so far only by the
SZD and the Grob factories.
The production process of Junior comprised od TWO DAYS in a SINGLE SHIFT
system, so one day in a two shifts, I have checked this. This was achieved
due to e.g far going integration of the elements of glider just like the
main spar which is simply a Z shaped layer of the glassfibre (if I
remember
correctly) and using the molds which didn't need the pressure forced
forming
of the fuselage in the molds (well I am not sure if I had translated it
properly into English). Simply the stucture could form itself when just
put
into molds (less workhours needed). This technologo also allowed to use
locally produced the "STR" (it's a brand I believe) glass cloth instead of
the Interglass cloth, and also it was possible to employ low skilled
employees (which are also a lot more affordable) at the production line if
needed.
It simply looks that simple technology could reduce lots of costs. Junior
is
a good example of the way we should follow. Apart from this, it makes an
excellent sailplane for these who just want to fly for fun.

I have no specific knowledge of the technology, so I can't say how it was
achieved, and for me personally... I think there should be some time for
finish too! I know that factory won't say a word on this (I suppose so)
as it is their technology which they use, but if properly marketed the
Junior could make this what the World Class supposed to be - a glider for
a
masses, safe, easy to fly, and affordable - all in one. By the way, I have
heard that Junior is produced under licence n Brasil, can anyone confirm
this information?

Returning to the previous post by mr Whiteley, the '55' is all glass, no
carbon inside, just the well designed glass design. No flapperons or
flaps,
as it's a standard class glider, BUT Diana... it's carbon, and it's
designer
mr Beres is one of the best specialists in using carbon materials here in
Poland. He runs his own business since he left SZD after it has gone bust
for a while: http://www.beres.com.pl/

With kindest regards,


--
Janusz Kesik
Poland
to reply put my name.surname[at]gazeta.pl
-------------------------------------
See Wroclaw (Breslau) in photography,
The XIX Century, the Festung Breslau, and photos taken today.
http://www.wroclaw.dolny.slask.pl


That now begs the question about the time required to build a Diana.

Frank Whiteley

U¿ytkownik "F.L. Whiteley" napisa³ w
wiadomo¶ci ...

cut
, and it's
designer
mr Beres is one of the best specialists in using carbon materials here
in
Poland. He runs his own business since he left SZD after it has gone
bust
for a while: http://www.beres.com.pl/


That now begs the question about the time required to build a Diana.

Frank Whiteley


Well, I lack the knowledge on this. I believe that mr Bogumil Beres, the
designer and manufacturer of Diana will be happy to answer questions like
that.
Go to the website http://www.beres.com.pl and simply send him an e-mail.

Regards,


--
Janusz Kesik
Poland
to reply put my name.surname[at]gazeta.pl
-------------------------------------
See Wroclaw (Breslau) in photography,
The XIX Century, the Festung Breslau, and photos taken today.
http://www.wroclaw.dolny.slask.pl