Gary, have you tried having the tow vehicle do a 180 at the end of the
taxiway and then do another pull back down the runway in the opposite
direction? You could probably get another 500'- 700' more height.
Hang gliders have done this successfully with payout winches.
However, they do have the advantage of a downward view of the tow
vehicle. __Mike




"Gary Boggs" wrote in message ...
Bill, this is a payout winch. The starter motor is for reeling the line
back in after the truck mounted winch gets to the end of the runway. Check
out the video:

http://www.nwskysports.com/




"Bill Daniels" wrote in message
news:QIV6d.147361$D%.8795@attbi_s51...

"Gary Boggs" wrote in message
...
My guess as to the force on line is probably something like 300lbs? I
think
the next mod we will incorporate will be a tensiometer on the line.
Right
now we use a pressure gauge on the brake line and as the disc brake
heats
up, the pressure required to get the correct tension on the line goes
up.
It would work much better if our winch operator was able to monitor the
actual tension on the line, instead of the pressure on the brake. If we
could find an electronic tensiometer, we could program it to operate the
brake, but this would make the winch even more complicated and
expensive.
I've searched the web for available tensiometers, but found nothing
suitable,
so I think we will just build one into our system.

The tension on the line should be about the same as the gross weight of
the
glider. 300 pounds will result in a poor launch. The tension on the line
is the result of cooperation between the pilot and the winch operator. No
matter how hard the winch tries to increase the line tension it won't
happen
unless the glider pilot pulls up.

A better idea is to use an RC model airplane telemetry package like RCAT
to
send the glider airspeed to the winch operator and let him control that.
The glider pilot can then control the line tension with the elevator.

I think it will require more power than a starter motor for that though.

Bill Daniels