Electric Winch Project

On Sun, 02 Sep 2018 20:37:24 +0000, 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

I like it!

Just get M C Escher to design the airfield and Bob's Your Uncle!


--
Martin | martin at
Gregorie | gregorie dot org

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 11:15:43 AM UTC-4, Dan Marotta wrote:
Didn't the German winch require being hooked up to the electrical grid?Â*
It seems the one currently under discussion would be self contained and
portable (on the back of a truck).


Dan, 5J

Hi Dan,

the Elektostart winch in Germany has 50 starter batteries on board which supplied the bulk of the current during the launch. Since the electric infrastructure is so much more densely developed in Europe, it is never too far to the next power tie-in. A relatively low Amp connection is all that's needed to recharge the batteries between launches. Some clubs operating this winch trenched a cable to either end of their field and just plug it in.
The early Elektrostart winches had some issues with the software for the controller, which - if I remember correctly - was an industrial VFD. There were some instances reported where the controller couldn't cope with line tension oscillations but that is all worked out now.
As much as I like the winch I built for my club - powered by one kick-a$$ Ford 460 BB - electric drive is the way of the future!

Uli
'AS'

I agree, Uli.

When Black Forest bought a small block Chevy winch from the Air Force
Academy.Â* I and a couple of others removed the engine and installed a
big block Chevy (454 cu. in.).Â* It was pretty healthy!

On 9/2/2018 3:32 PM, AS wrote:
On Sunday, September 2, 2018 at 11:15:43 AM UTC-4, Dan Marotta wrote:
Didn't the German winch require being hooked up to the electrical grid?
It seems the one currently under discussion would be self contained and
portable (on the back of a truck).

Dan, 5J
Hi Dan,

the Elektostart winch in Germany has 50 starter batteries on board which supplied the bulk of the current during the launch. Since the electric infrastructure is so much more densely developed in Europe, it is never too far to the next power tie-in. A relatively low Amp connection is all that's needed to recharge the batteries between launches. Some clubs operating this winch trenched a cable to either end of their field and just plug it in.
The early Elektrostart winches had some issues with the software for the controller, which - if I remember correctly - was an industrial VFD. There were some instances reported where the controller couldn't cope with line tension oscillations but that is all worked out now.
As much as I like the winch I built for my club - powered by one kick-a$$ Ford 460 BB - electric drive is the way of the future!

Uli
'AS'

--
Dan, 5J

On Sunday, September 2, 2018 at 5:43:29 AM UTC-7, 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

It is why all locomotives are diesel-electric: you get full torque at zero RPM, no transmission is required, and line tension and acceleration are easily controlled. Of course, the engine can be much smaller as the winch time is a small percentage of clock time.

Tom

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

Hi Goto,

oh my god! Let's not do something new! Lets not leave the beaten path!
That's exactly how we ended up with planes still powered by '30s technology - no progress there for decades.
As Herb said, Bill's design and development is a huge step forward and it should be supported by the US-soaring community because it will make a difference in the future!

Uli
'AS'

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

On Sunday, September 2, 2018 at 6:19:12 PM UTC-4, 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

On Sunday, September 2, 2018 at 6:19:12 PM UTC-4, 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

I think it would take almost 1 mg to start a 430 hp electric motor DOL. Huge power requirement.

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

I think it would take almost 1 mg to start a 430 hp electric motor DOL. Huge power requirement.

Bob - they are all using frequency controllers! These are not your on-off industrial motors used to power a belt conveyor or hammer-mill! Think electric cars ...
Uli
'AS'