"Michel Talon" wrote in message
...
Bert Willing wrote:

As to inefficient production methods - building a couple of hundred
gliders
from negative moulds is handcrafting, nothing else. If you want to have
more
performant production tools, you need *much* higher numbers to be able
to
compensate the tooling investment. The only way to reduce cost is either
cutting down on the finish (has been done successfully by Grob), or
going to
do the production in countries with low wages (as done by SH and DG).
Still with the high prices for last generation gliders, companies like
LS go
belly up...


Shure, and this is really a pity. Still i am convinced that it is
absolutely essential to cut radically on prices. After all, other
industries succeed perfectly in cutting prices by a factor of two
in a couple of years to survive in a competitive market. I see many
examples of industries where there is a constant effort
to augment productivity, diminish prices, etc. I am convinced that
the glider factories have never done this reflexion effort
and content themselves to augment their tarifs each year.
This destroys the sport, destroys their market, and will ultimately lead
to their disparition. Gliding is by nature a sport for young people,
not for rich people. You will have hard time recruiting guys who
are both rich, have a lot of free time, good reflexes, etc. At the
end of the day it remains only a crew of retirees to animate the clubs.

Michel TALON


I agree Michel. There HAS to be a way to reduce production costs. There
are thousands of people that will tell you that "it can't be done". My
experience tells me that these are "negative experts" who always know
exactly, to the Nth decimal place, why whatever you want to do can't be
done, but are totally silent when asked how something CAN be done.

I tend to view the problem as an engineering one rather than an economic
one. Worse finishes by cheaper labor is not a rewarding way to go. I call
this a "negative compromise" where you end up paying a little less (or maybe
the same) for a much worse product.

So, how might it be done? Start with computers, materials and processes.
Large CNC milling machines can produce extremely accurate plugs or even
finished molds. If the process of making the flying part accurately
replicates these CNC generated mold surfaces, little post molding work
should be needed. The fact that a lot of post molding work IS needed today
says a lot about the materials and methods used.

A very promising area the homebuilders are playing with is "Vacuum assisted
resin Infusion" which reduces the labor of wet layup by 75%. Lay the dry
fiber in place on the mold and vacuum bag it. Then, inject resin at
strategic places so it flows through the whole part. The resin content
drops to around 25% instead of the 40 -50% typical of wet layup and voids
are almost completely eliminated. The result is a lighter, stronger, more
accurate and cheaper part.

It would be very economical if the resin saturated part could be heat cured
while in the mold. If the mold is fiberglass, it will warp with repeated
temperature cycles (PIC 20D). Making the mold out of aluminum is expensive,
but you only have to pay for it once. The payback is fast cycle times
because you can heat the part in the mold so it cures in minimum time. You
may get three parts per day instead of only one and the part will be far
more temperature tolerant.

There must be thousands of tricks like this that drive up quality while
cutting costs. That's the way to go. Think outside the box.

Bill Daniels