How are joysticks 'powered' in gliders?

I note that some gliders are controlle with a joystick which
makes me curious as to how the control surfaces are powered.

Assuming these are useable by people who lack the forearms of
a truck driver, how are they powered?

Do these systems use electric servos with a battery recharged
on the ground? Do they use vaccumm assist from a venturi?

Just asking?

--

FF

wrote in message
oups.com...

I note that some gliders are controlle with a joystick which
makes me curious as to how the control surfaces are powered.

Assuming these are useable by people who lack the forearms of
a truck driver, how are they powered?

Do these systems use electric servos with a battery recharged
on the ground? Do they use vaccumm assist from a venturi?

Just asking?

--

FF


You really need to visit the nearest gliderport and take a ride. Assuming
you are in the USA, check www.ssa.org and click the button "Where to fly" to
find the nearest location.

One of the great beauties of gliders is their simplicity. Usually, the only
"power" in the glider is a small battery to power the radio and a few
instruments. Everything else is powered by the pilot.

The control forces in modern gliders are small enough that pilots can fly
with their finger tips most of the time. If you see a glider pilot with
"truck driver forearms", it's from assembling the glider, not flying it.

Bill Daniels

Actually Fred, your question is interesting to us at Freedoms Wings Canada
www.freedomswings.ca, where we are indeed looking to design a glider control
system utilizing a 'joystick' to control servos (from autopilots) driving
the control surfaces. This would enable a larger population of pilots with
disabilities to fly, providing control to paraplegics and some higher
functioning quadriplegics who have limited strength in their arms and
wrists.

We also envision a second phase where we will supplement the foregoing with
a microelectric gyro for yaw control, and thereby enable a 'sip 'n puff'
control for the glider in flight. A Professor of biomedical engineering at
the University of Toronto, and the folks at Barry Aviation
www.barryaviation.com, believe this can be done, even with a limited budget.

I can't begin to describe how exciting this would be for someone who can at
present drive only a sip 'n puff wheelchair.


wrote in message
oups.com...

I note that some gliders are controlle with a joystick which
makes me curious as to how the control surfaces are powered.

Assuming these are useable by people who lack the forearms of
a truck driver, how are they powered?

Do these systems use electric servos with a battery recharged
on the ground? Do they use vaccumm assist from a venturi?

Just asking?

--

FF

To add to Bill's explanation, control rods through
belcranks is the simplest. Some older gliders used
cables and pulleys. Some early glass gliders used complex
gearboxes to convert linear into rotary movement and
modern gliders with flaperons have mixer arrangements.
All have one thing in common they are directly mechanical.
In most modern gliders the stick forces are very light,
frightening so in something like a Discus. Some of
the older gliders did get heavy at speed, for instance
at 80kts the ailerons on a Sedbergh (Slingsby T21)
are set in concrete requiring two hands or even four
if available, not to mention the foot behind the stick
to relieve the need for forward pressure on the stick.

DJ

At 15:30 25 February 2005, Bill Daniels wrote:

wrote in message
roups.com...

I note that some gliders are controlle with a joystick
which
makes me curious as to how the control surfaces are
powered.

Assuming these are useable by people who lack the
forearms of
a truck driver, how are they powered?

Do these systems use electric servos with a battery
recharged
on the ground? Do they use vaccumm assist from a
venturi?

Just asking?

--

FF


You really need to visit the nearest gliderport and
take a ride. Assuming
you are in the USA, check www.ssa.org and click the
button 'Where to fly' to
find the nearest location.

One of the great beauties of gliders is their simplicity.
Usually, the only
'power' in the glider is a small battery to power the
radio and a few
instruments. Everything else is powered by the pilot.

The control forces in modern gliders are small enough
that pilots can fly
with their finger tips most of the time. If you see
a glider pilot with
'truck driver forearms', it's from assembling the glider,
not flying it.

Bill Daniels

Bill Daniels wrote:
....

You really need to visit the nearest gliderport and take a ride.
Assuming
you are in the USA, check www.ssa.org and click the button "Where to
fly" to
find the nearest location.


Uh, I think you're right. I belong to a local flying club, one of
our members is a gliding enthusiast who flys out of another club
in Pensylvania. I suspect I could go with her up there pretty much
any weekend.

--

FF

In one of Dennis Wright's editorials he wrote about several
ideas to help promote soaring. On the list were some things already
being done (CAP, EAA young eagles getting a new name, etc.)

One thing in the list I found very interesting, however,
was the idea of SSA membership and club "co-membership." So
if you were an SSA member, or maybe if you were a club
member somewhere, you would be accepted into other club
without paying an entry fee, etc.

I discussed this with some clubs and commercial operators,
and they weren't too keen on the no application fee and no dues
idea.

BUT, we came up with the idea that an SSA member could
walk into any club or commercial operator, and any application fees or
doubling of charges, etc, would be waived for one day a year.

Call it the "member for a day" program. Kind of like "king
for a day." Bring your Soaring magazine confirming you are
an SSA member. Walk in to any club and show it, and
you'll be treated like a member that day. No initiation fees,
etc. Go fly with an instructor, or another club pilot.

Details of wanting to fly one's own glider there using the club
for tows, or details of wanting to fly club equipment solo, would
be arranged seperately.

I think this would realy help the walk-in stuff. No mystery,
no hidden charges, no having to "investigate" what is offered.
Show up at the door and get treated like a part of the club.
Welcome!

I also think this might cross-pollenate more for current glider pilots.
Haven't you always wanted to go fly just one day maybe at some
gliderport you know nothing about? A little intimidated
about having to face fees and applications? Wouldn't it be nice
to know you can be treated like a member for a day?

I'm sure there are plenty of clubs already doing this, but
I'd love to see this as a blanket "Welcome!" assurance
from SSA. Country clubs and sailing clubs often honor
memberships at other clubs for short-term visitors.
Just climb aboard the boat and we'll go sail together, and
you gotta pay for your steak at the end like all the other members.

If it's just once a year, I can't see this idea cutting into
dues or initiation fees much.

Anyway, what do you all think? Wouldn't it be fun to
walk in to any club with your Soaring magazine and say
"I'd like to be a member for a day?"

In article . com,
wrote:

Bill Daniels wrote:
...

You really need to visit the nearest gliderport and take a ride.
Assuming
you are in the USA, check www.ssa.org and click the button "Where to
fly" to
find the nearest location.


Uh, I think you're right. I belong to a local flying club, one of
our members is a gliding enthusiast who flys out of another club
in Pensylvania. I suspect I could go with her up there pretty much
any weekend.

--

FF



--

------------+
Mark J. Boyd

On 27 Feb 2005 10:49:36 -0800, wrote:

Bill Daniels wrote:
...

You really need to visit the nearest gliderport and take a ride.
Assuming
you are in the USA, check www.ssa.org and click the button "Where to
fly" to
find the nearest location.


Uh, I think you're right. I belong to a local flying club, one of
our members is a gliding enthusiast who flys out of another club
in Pensylvania. I suspect I could go with her up there pretty much
any weekend.

Just to return to your original question, what caused you to suspect
that gliders needed power assisted controls ?
AFAIK, there is no power assistance in the common Cessna and Piper GA
aircraft, unless you are using the autopilot. Am I wrong in this
assumption ?
John G.

Just to return to your original question, what caused you to suspect
that gliders needed power assisted controls ?
AFAIK, there is no power assistance in the common Cessna and Piper GA
aircraft, unless you are using the autopilot. Am I wrong in this
assumption ?

No, you are not. rudder, ailerons, and elevators are direct cabled with
no power assist. Cessna (from the early '60s on) uses an electric motor
for the flaps but even this was un-necessary, IMHO, for the 182 and below.

Tony V.

John Giddy wrote:


Just to return to your original question, what caused you to suspect
that gliders needed power assisted controls ?
AFAIK, there is no power assistance in the common Cessna and Piper GA
aircraft, unless you are using the autopilot. Am I wrong in this
assumption ?


It seemed to me that if there was enough mechanical advantage in
a joystick, no one would ever have bothered to design with a
full-length control stick. The latter takes up more space and
weighs more.

--

FF

Don Johnstone wrote:
...
In most modern gliders the stick forces are very light,
frightening so in something like a Discus. Some of
the older gliders did get heavy at speed, for instance
at 80kts the ailerons on a Sedbergh (Slingsby T21)
are set in concrete requiring two hands or even four
if available, not to mention the foot behind the stick
to relieve the need for forward pressure on the stick.


What is it that causes the difference between the two?

--

FF