Lowest power tow

On Monday, January 20, 2020 at 9:34:30 AM UTC-5, wrote:
"Is it time to design the sailplane towing version of the Dragonfly for when we run out of Pawnees? Be interesting to see what the soaring brain trust could come up with."

If only there was a way to get gliders in the air that didn't require dangerous and expensive rare airplanes... if only there was a "brain trust" elsewhere in the world we could look to for answers. Sigh... well it looks like we're alone with this mystery.

Giant rubber bands? Better yet a giant rubber band powered towplane.

On Monday, January 20, 2020 at 10:16:52 AM UTC-5, wrote:
On Monday, January 20, 2020 at 9:34:30 AM UTC-5, wrote:
"Is it time to design the sailplane towing version of the Dragonfly for when we run out of Pawnees? Be interesting to see what the soaring brain trust could come up with."

If only there was a way to get gliders in the air that didn't require dangerous and expensive rare airplanes... if only there was a "brain trust" elsewhere in the world we could look to for answers. Sigh... well it looks like we're alone with this mystery.

Giant rubber bands? Better yet a giant rubber band powered towplane.

How about a long string of sorts which we lay out along the field and tug on from the end or wind it up like on a fishing reel on steroids powered by something .... I can see it in mind now .... ;-)

Uli
'AS'

On Monday, January 20, 2020 at 10:32:11 AM UTC-5, AS wrote:
On Monday, January 20, 2020 at 10:16:52 AM UTC-5, wrote:
On Monday, January 20, 2020 at 9:34:30 AM UTC-5, wrote:
"Is it time to design the sailplane towing version of the Dragonfly for when we run out of Pawnees? Be interesting to see what the soaring brain trust could come up with."

If only there was a way to get gliders in the air that didn't require dangerous and expensive rare airplanes... if only there was a "brain trust" elsewhere in the world we could look to for answers. Sigh... well it looks like we're alone with this mystery.

Giant rubber bands? Better yet a giant rubber band powered towplane.

How about a long string of sorts which we lay out along the field and tug on from the end or wind it up like on a fishing reel on steroids powered by something .... I can see it in mind now .... ;-)

Uli
'AS'

That is brilliant. We could attach a pulley that winds that string up to a motor then mount the motor/pulley arrangement in the belly of a glider and wind up into the sky.

On Monday, January 20, 2020 at 9:16:52 AM UTC-6, wrote:
On Monday, January 20, 2020 at 9:34:30 AM UTC-5, wrote:
"Is it time to design the sailplane towing version of the Dragonfly for when we run out of Pawnees? Be interesting to see what the soaring brain trust could come up with."

If only there was a way to get gliders in the air that didn't require dangerous and expensive rare airplanes... if only there was a "brain trust" elsewhere in the world we could look to for answers. Sigh... well it looks like we're alone with this mystery.

Giant rubber bands? Better yet a giant rubber band powered towplane.

Yes! I think you have come up with a new idea!

On Fri, 24 Jan 2020 10:57:53 -0800, Colten Coughlin wrote:

On Monday, January 20, 2020 at 9:16:52 AM UTC-6,
wrote:
On Monday, January 20, 2020 at 9:34:30 AM UTC-5,
wrote:
"Is it time to design the sailplane towing version of the Dragonfly
for when we run out of Pawnees? Be interesting to see what the
soaring brain trust could come up with."

If only there was a way to get gliders in the air that didn't require
dangerous and expensive rare airplanes... if only there was a "brain
trust" elsewhere in the world we could look to for answers. Sigh...
well it looks like we're alone with this mystery.

Giant rubber bands? Better yet a giant rubber band powered towplane.

Yes! I think you have come up with a new idea!

One of these was built 10-20 years ago (in California IIRC), but never
flown AFAIK. It wasd pretty much just a giant version of an old-fashioned
rubber powered beginners free flight model, except the rubber motor was
inside a tubular fuselage rather than strung under a wooden beam.

There was a huge (20 ft diameter?) two-blade prop on the front, a long,
stalky two-wheel undercarriage with a single axle across between the
undercarriage legs and a wheel on each end. The 90kg rubber motor was
inside a narrow, tubular wooden (balsa?) fuselage. The pilot sat in a
small open nacelle mounted on the centre of the undercarriage axle. He
held an ordinary RC transmitter that controlled two large servos
connected to the rudder and elevators. No ailerons, flaps or airbrakes
were fitted. The wings had plenty of dihedral for roll stability, which
also meant that simply feeding in rudder would roll it into a turn.

They wound it up using the power take-off on a tractor.

It got as far as taxiing trials with the wings removed.

Not long after that, the website vanished. I don't know why it all went
silent and have never heard anything more about it since then.


--
Martin | martin at
Gregorie | gregorie dot org

Wow!Â* Imagine what would happen if the rubber band was over wound...Â*
And another occurrence of fly-by-wire(less) control. :-D

On 1/24/2020 2:24 PM, Martin Gregorie wrote:
On Fri, 24 Jan 2020 10:57:53 -0800, Colten Coughlin wrote:

On Monday, January 20, 2020 at 9:16:52 AM UTC-6,
wrote:
On Monday, January 20, 2020 at 9:34:30 AM UTC-5,
wrote:
"Is it time to design the sailplane towing version of the Dragonfly
for when we run out of Pawnees? Be interesting to see what the
soaring brain trust could come up with."

If only there was a way to get gliders in the air that didn't require
dangerous and expensive rare airplanes... if only there was a "brain
trust" elsewhere in the world we could look to for answers. Sigh...
well it looks like we're alone with this mystery.
Giant rubber bands? Better yet a giant rubber band powered towplane.
Yes! I think you have come up with a new idea!
One of these was built 10-20 years ago (in California IIRC), but never
flown AFAIK. It wasd pretty much just a giant version of an old-fashioned
rubber powered beginners free flight model, except the rubber motor was
inside a tubular fuselage rather than strung under a wooden beam.

There was a huge (20 ft diameter?) two-blade prop on the front, a long,
stalky two-wheel undercarriage with a single axle across between the
undercarriage legs and a wheel on each end. The 90kg rubber motor was
inside a narrow, tubular wooden (balsa?) fuselage. The pilot sat in a
small open nacelle mounted on the centre of the undercarriage axle. He
held an ordinary RC transmitter that controlled two large servos
connected to the rudder and elevators. No ailerons, flaps or airbrakes
were fitted. The wings had plenty of dihedral for roll stability, which
also meant that simply feeding in rudder would roll it into a turn.

They wound it up using the power take-off on a tractor.

It got as far as taxiing trials with the wings removed.

Not long after that, the website vanished. I don't know why it all went
silent and have never heard anything more about it since then.



--
Dan, 5J

On Sat, 25 Jan 2020 08:00:32 -0700, Dan Marotta wrote:

Wow!Â* Imagine what would happen if the rubber band was over wound...
And another occurrence of fly-by-wire(less) control. :-D

Yes, doesn't bear thinking about!

It turns out it was only 90 pounds of best quality 1/4" aero strip as
used to power competition models - an unstretched length of 17,500 feet,
5350m, 3.5 miles. It was made up into a 400 strand motor 25 feet (7.7m)
long and expected to take 700-800 turns when fully wound. The airframe
weighed 220 lbs without the rubber.

Here's the most complete version of the story that I've found, complete
with a picture of the Rubber Bandit rigged ready to fly:

http://sustainableskies.org/a-chance-to-unwind/

.... but it doesn't say why the Rubber Bandit never flew. Elsewhere I
found an estimate that the 90lb rubber band cost $US 180,000 and hinted
that this had a bearing on it not flying. But that can't be right,
because even at today's prices that 90 lb motor would only cost $US 3500,
and the article didn't say they needed a new rubber band before they
could go and fly.

BTW, this wasn't the first rubber powered manned aeroplane: in around
1988 an EAA chapter built and flew the first one. They modified a Lazair
ultralite by installing a vastly extended centre boom containing a more
modestly sized bundle of aero strip and with a big prop on the front.
This only had 23 lbs of rubber in it, but did manage to fly 1000 ft:

http://www.lightsportaircraftpilot.com/
rubberband_powered_ultralightaircraft/index.html

Maybe its my model flying background, but I think the Rubber Bandit looks
a lot more elegant than the RB-1.


--
Martin | martin at
Gregorie | gregorie dot org

Wow! This is all very interesting!