Electric Winch Project

I suspect the challenges associated with digging and maintaining the 1km deep holes at each end of the runway might get in the way of an otherwise excellent idea! You could of course make them shallower with some pulley's but I think that would interfere with the aesthetic simplicity of the idea.

Mark.

On Monday, September 3, 2018 at 6:45:05 AM UTC+10, Chris Rowland wrote:

I've wondered if the best way to launch is by gravity, a weight falling
into a mine shaft and attached to the glider by a cable. If you have a
supply of water then the weight is by filling a tank. At the end of the
launch you dump the water, pull the much lighter tank back up, then refill
it. Given enough room you could have a circular airfield round the mine
shaft. The only energy that you need to supply is to retrieve the tank and
cable.

A few things to sort out but it's a start.

Chris

On Sunday, September 2, 2018 at 9:29:48 PM UTC-4, WB wrote:
You bunch of electric sissies! I want a glider with a huge freakin pulse jet strapped to it burning heavy crude or coal tar, throwing fire out the back for half a mile, sounding like Gabriel has jacked his trumpet into an amplifier powered by relativistic jets from a supermassive black hole.

Wow - that sound dark and apocalyptic! ;-)

Uli
'AS'

I like the way you think! :-D

Dan

On 9/3/2018 3:06 PM, Skypilot wrote:[color=blue][i]
Hi Dan, all understood, all of the technology is here now other than the
small high capacitance cheap batteries. We have Tesla’s,
GP15’s, self launch Libelle’s and in my and your country
lots of sunshine. In fact one of our club legends who has been gliding
for 65 years drove his new Tesla to the club the other day from 220km
away. It took two days to recharge on the club mains power
I totally agree about the power and am the biggest supporter of nuclear
power but we shall leave that for another day. The prop drag is only
related to the torque attached to it, RATS have been around for ages, a
goverener in the prop hub will load up the elec motor and via reverese
current charge the battery, cleverer people than me will guess but it
will probably have to be a 4kt thermal or so. It will all come down to
the batteries and the various authorities allowing it to take place. You
will probably still have a power bill to pay for the grid to allow
society to function.

Dan Marotta;975487 Wrote:
That was a pretty interesting bit of science fiction.Â* And the
proceeding was not meant as criticism, only that most of the mentioned
technology is so far into the future that most, if not all of us will
never see it.

My one criticism is not acknowledging that it takes power to make power
(currently) and using a propeller to drive a motor/generator in flight
will create a LOT of drag which translates directly into sink rate.Â*
There's no free lunch yet, except in California.

On 9/2/2018 3:08 PM, Skypilot wrote:
I find all this stuff sexy, in Australia we all live in a bit of a
fantasy of energy, we export our LPG, Coal and Oil like it’s
going
out of fashion and the “green” movements of our parties
ensure that subsidies and grants are available to clubs and
organisations for being green. My home club of Kingaroy would be a
perfect site to go for a huge grant for four elec whinches 2xmain and
2x
retrieve. The runway area is 2000m x100m of grass right next to a
bitumen runway, there is power available within 200m of both winch
sites. The only problem is the fact that it’s a certified runway
with probably 1-2 private movements per hour, so the local Shire
council
are unlikely to approve winching. It’s a pity as there is a coal
mine 20km away and there is a planned coal mine next to the airstrip
and
we have elections soon. If there was ever a time to pitch an
alternative
to burning smelly dinosaur bones and reducing the noise foot print for
our solar powered sport now is it

I guess the panacea is to have an electric winch next to a battery bank
powered by solar panels. In Australia this is feesable given the space
and sunshine, BUT here is the crux - it’s battery technology.

The future will have elec self launch gliders, elec tow planes, elec
winches and all of this will be powered by a battery system that is
dual
use. The batteries will be in runway edges, house bricks and other
structural items not just a battery.

You will wake up in your house that is a storage facility hooked to the
grid, most of the time you will be a next exporter of energy.

Jump in your electric car and drive up to the field.

Unplug your elec self launch Libelle and plug your car in, your hangar
will have a storage battery bank in the wall bricks.

Tow your glider out to the runway with your elec golf cart and launch
into the wild blue yonder with your retractable self launch system with
prop goverening.

Once airborne you will go find a big fat thermal and redeploy your self
launch prop mast and reverse the prop to recharge your batteries
thereby
extending your range.

The next type of comps will be range comps that will allow much greater
distances and speeds, perhaps one day we will see solar panels on wings
that can feed power to the battery system built into the composite
fibres.

Fly until sunset and head to the clubhouse for a beer.

I just don’t understand why so many on here are negative to
people
trying to improve things, because let’s face it if we don’t
improve things our sport is dead.

Justin




--
Dan, 5J

On Sunday, September 2, 2018 at 8:29:48 PM UTC-5, WB wrote:
You bunch of electric sissies! I want a glider with a huge freakin pulse jet strapped to it burning heavy crude or coal tar, throwing fire out the back for half a mile, sounding like Gabriel has jacked his trumpet into an amplifier powered by relativistic jets from a supermassive black hole.

Better still, Project Pluto...

66

On Tuesday, September 4, 2018 at 9:46:56 AM UTC-7, kirk.stant wrote:
On Sunday, September 2, 2018 at 8:29:48 PM UTC-5, WB wrote:
You bunch of electric sissies! I want a glider with a huge freakin pulse jet strapped to it burning heavy crude or coal tar, throwing fire out the back for half a mile, sounding like Gabriel has jacked his trumpet into an amplifier powered by relativistic jets from a supermassive black hole.

Better still, Project Pluto...

66

The Diesel-Electric idea seems great.
It would be nice to run a winch where the noise of a big block V-8 doesn't drown out the singing of the rope.
Hardly science-fiction, as D-E engines brought an end to the steam age of trains in the 1960s.
Wishing the best results to all designing new stuff!
Jim

At 16:46 04 September 2018, kirk.stant wrote:
On Sunday, September 2, 2018 at 8:29:48 PM UTC-5, WB wrote:
You bunch of electric sissies! I want a glider with a huge freakin
pulse
=
jet strapped to it burning heavy crude or coal tar, throwing fire out the
b=
ack for half a mile, sounding like Gabriel has jacked his trumpet into an
a=
mplifier powered by relativistic jets from a supermassive black hole.

Better still, Project Pluto...

66

There's always the Yak 110, two Yak55s bolted together with a jet engine.

https://www.youtube.com/watch?v=nWtOQ2nxDtE

Chris

On Sunday, September 2, 2018 at 4:19:12 PM UTC-6, Bob Youngblood wrote:
On Sunday, September 2, 2018 at 8:43:29 AM UTC-4, gotovkotzepkoi wrote:
Germans have had an electric winch for a long time. Nothing now. Don't
hold your breath for one built in the US. Won't happen. Charge with an
internal combustion engine? What's the point? Why not just use a piston
engine for the winch then?




--
gotovkotzepkoi


I can tell you that the current starting load for a 430 hp electric motor is substantial. Don't know if they are using a soft start or something equal it takes a lot of power to start a 430 hp electric motor. The amp requirements are huge, interesting concept, huge electric requirements. Bob
-------------------

Bob, you are confused by old-school, garden variety synchronous AC induction motors which do require a lights dimming surge of power to get them up to synchronization with a fixed power line frequency. They're inefficient so they're largely been replaced by better technology. The tech is changing so fast it's hard to keep up.

The variable frequency motor (PMSM) used in the winch does not require such a surge to start. RPM is a function of frequency and torque is a function of current. The current it draws is proportional to the torque output required.

Variable frequency AC is provided by a "traction inverter" or VFD which very efficiently converts battery DC to 0 to ~1,000 Hz 3-phase AC. The motor starts gently at 0 Hz and smoothly revs up as the frequency is increased.

The battery is kept charged by a relative small power source which need only supply the average power demand over many launches. As designed, the winch will have far more than needed from a PTO driven generator but almost any source of electricity would do - even a 2,000 Sq Ft solar cell array would work handily.

Battery cost is already so low there is a minimal impact on the cost of the winch. We have quotes for a bigger than needed battery for less than $2,000 and prices are dropping very fast.

I know battery powered winches benefiting from the automotive boom in motors and batteries is our future. But there's nothing like a big block engine roaring through a pair of open bog headers to get the hair standing up on your arms. Everyone within half a mile knows that the gods of combustion have arrived, and they are angry. The high pitched scream of a electric motor running on an inverter, just ain't the same.

Kudos to Bill for taking point on this, just remember the guys on point get shot at a lot.

SF

On Thursday, September 6, 2018 at 7:34:36 PM UTC-4, SF wrote:
I know battery powered winches benefiting from the automotive boom in motors and batteries is our future. But there's nothing like a big block engine roaring through a pair of open bog headers to get the hair standing up on your arms. Everyone within half a mile knows that the gods of combustion have arrived, and they are angry. The high pitched scream of a electric motor running on an inverter, just ain't the same.

Kudos to Bill for taking point on this, just remember the guys on point get shot at a lot.

SF

Scott is talking about this one:
https://www.youtube.com/watch?v=YePIJKs5me0
Make sure to have the volume cranked up.... :-)

Uli
'AS'

It is much easier to measure and control the line tension with an electric motor, eliminating the rocket launch a single seater can get when the winch driver has been
launching the training two seater all day. On my first flight in a Hornet on the winch, the acceleration was so great I could not prevent the glider from rotating immediately
with full forward stick, 5 terrifying seconds....