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Old April 3rd 07, 06:35 AM posted to rec.aviation.soaring
Markus Graeber
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Posts: 87
Default Airspeed control during ground launch?

The only problem with the Hydrostart winch is that it is about the
most expensive winch around (and I haven't heard about them having
sold another one even though they do have a website and seem to have
commercialized the design)... The technology is great if you can
afford it/have the necessary resources available to the club. The guys
who build the Hydrostart are experts in their field and do related
stuff professionally resulting in an awesome winch. But the resources
they had available is not what you find in your average club and, not
surprisingly, the Aero Club Salland is one of the biggest and most
active in NL (hence the 6 drums). Interestingly enough a single drum
setup with retrieve winch could probably achieve the same launch rates
albeit at a far smaller price tag.

Process control using simple, rugged PLC's might be easy to implement
for the expert but you gotta have the expert in the first place. A
simple mechanical setup with off-the-shelf parts can be built/
maintained by a lot more people than a hydrostatic drive with PLC
based controls, no matter how simple they are. If you got the
resources, great, but for the rest of us a more conventional setup
that might lack the last 5% of performance but is reliable in daily
use is more reasonable. Only on very short fields where every meter
counts the significant extra investment those last 5% might cost you
would be really worth paying for. Otherwise I'd rather get another
nice glider for the money saved, as long as decent launches are
assured this will matter more to the members than having the fanciest
winch around.

Markus