The starter motor pulley is variable and we have it set at about 1.5inches,
the pulley on the drum is 14inches. We reel in 1000ft of line in about 30
seconds? We do use a chute on the line. We have to choke it down when the
wind is high because when it opens up very big, there is too much drag for
our starter motor and it bogs down.

The drum diameter is 21inches. We found that if it was smaller, the tension
on the line and the leverage of a smaller drum caused the line to cut into
itself when you were paying out.

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.

I will get some current pictures of our winch up on the web site soon. Let
me know if anyone has any more questions.

http://www.nwskysports.com/
Gary Boggs, CFIG
3650 Airport Drive
Hood River, OR
97031-9613
541.490.5557
503.708.8869





"Chris Ashburn" wrote in message
news:qZM6d.1603$mS1.1464@fed1read05...

Hi Gary,

Interesting, my brain was working on a system very similar with the
starter motor retrieve.
What's your gear ratios and drum diameter?
How long to pay-back on 1000ft of line?
I didn't see a chute on the line, but you're driver stopped pretty close
the wider cross-road on the end of the run.

My drag mechanism was a hydraulic motor with a pressure regulator on
the output side. Torque limiting pay-out tension would be very easy
to control and calibrate.

Any idea what tension you're generating to trigger the pay-out?

The whole thing was going to be a bolt-on using a 2" receiver socket
on the back of any tow vehicle.

Please, some pictures?

Chris

Gary Boggs wrote:

I forgot to add that there is a modified starter motor on the spool and
after the glider releases, the operator reels in the line and the
parachute
falls down very near the tow vehicle. During the initial trials we were
using some poly rope and had some trouble with the line cutting into the
wrapped line on the real and had a few line breaks. We increased the
drum
diameter and went to synthetic line and have had no more line breaks
since.


"Gary Boggs" wrote in message
...

The reason we are using a pay out winch instead of a regular winch is
that
at our airport, there are taxi ways on both sides of the main runway,
and

no

large grass area that we could use that wouldn't involve having the
winch
line laying across places that other planes would have to taxi across.

The

airport managers and I agreed that this would make it very difficult and
dangerous to use a normal long line winch here. A couple of members of

the

Willamette Valley Soaring Club had already built this pay out winch to

near

completion so I approached the airport managers here in Hood River with

the

idea of using this type of winch instead. They agreed that this would
be
much safer and an acceptable launch method.

I bought the winch from my buddies and have made several refinements to

work

out some bugs and now it's working very well. The pay out winch has a

spool

of rope with a disc brake on it, set to let line out when the glider
pulls
harder than the drag is set. In some ways this is safer than a normal

winch

because it makes it almost impossible to break the line if the drag is
set
correctly. If the glider balloons up, the line just pays out faster,
instead of breaking, while still maintaining the pull on the line.

I don't think we are able to get quite as high as we would be able to
with

a

regular winch but with 3000ft of runway and no wind, we get 800 to 1000
feet and with a 20mph wind, we have gotten as high as 1300ft so far in
our
2-33 with a cg hook. We are still working on just what is the optimal

speed

for the tow vehicle and drag setting and I'm hoping we will be able to
get
as high as 1500ft.

Gary Boggs, CFIG
3650 Airport Drive
Hood River, OR
97031-9613
541.490.5557
503.708.8869



"Gary Boggs" wrote in message
...

I thought I'd post this with a new subject line so no one missed it.

We put a video of our pay-out winch on our web site:

http://www.nwskysports.com/