$1 billion BMS Ooops...

2G wrote on 3/2/2021 7:25 PM:
On Tuesday, March 2, 2021 at 6:28:27 PM UTC-8, Andrzej Kobus wrote:
On Tuesday, March 2, 2021 at 4:10:48 PM UTC-5, ProfJ wrote:
On Wednesday, 24 February 2021 at 14:42:01 UTC-7, wrote:
https://insideevs.com/news/490300/hy...ll-82000-bevs/
Discus amongst yourselves...
Some comments:

- High current draw for VTO launches (Lilium) - IIRC they are planning to use supercapacitors to provide the current boost so that the batteries don't have to. A supercapacitor/LiPo combination makes a lot of sense for that problem.

- Electric vs. gas: a very experienced motorglider ferry pilot, who I am sure does not want to be named, once told me when discussing Stemmes: "I've had every known Stemme issue except the in-flight fire, I'm not looking forward to that one..." I side with Eric here - we have normalized all the hassle that goes with gas self-launchers. When we get mature technology electric self-launchers, they'll dominate. Current complaints about electric sound exactly like the complaints about electric cars, before Tesla got it right.
So how big is the electric glider market vs. electric car market? Things get done with proper research and funding. I don't see that happen for the glider market. I suggest you review David's presentation. He discussed this point.

ICO glider engines have been developed over the last 70 years or so. And, then, many of them have come from the 2-cycle engine applications such as snowmobiles and ultralights. The electric glider market is much more immature..

That immaturity means they have a lot of promise, compared to the ICE gliders. We know in 5
years the performance of the electrics will increase significantly; the fossil fueled ones -
not nearly so much. Even at the current immature stage, they are so desirable, all the major
manufacturers, and some of the second tier, offer at least two electric models in mast or FES
varieties.

I suggest that in maybe 5, but certainly in 10 years, the discussions will no longer be about
gas vs electric, but which electric to buy.

--
Eric Greenwell - Washington State, USA (change ".netto" to ".us" to email me)
- "A Guide to Self-Launching Sailplane Operation"
lyhttps://sites.google.com/site/motorgliders/publications/download-the-guide-1

On Tuesday, March 2, 2021 at 8:27:55 PM UTC-8, Eric Greenwell wrote:
2G wrote on 3/2/2021 7:25 PM:
On Tuesday, March 2, 2021 at 6:28:27 PM UTC-8, Andrzej Kobus wrote:
On Tuesday, March 2, 2021 at 4:10:48 PM UTC-5, ProfJ wrote:
On Wednesday, 24 February 2021 at 14:42:01 UTC-7, wrote:
https://insideevs.com/news/490300/hy...ll-82000-bevs/
Discus amongst yourselves...
Some comments:

- High current draw for VTO launches (Lilium) - IIRC they are planning to use supercapacitors to provide the current boost so that the batteries don't have to. A supercapacitor/LiPo combination makes a lot of sense for that problem.

- Electric vs. gas: a very experienced motorglider ferry pilot, who I am sure does not want to be named, once told me when discussing Stemmes: "I've had every known Stemme issue except the in-flight fire, I'm not looking forward to that one..." I side with Eric here - we have normalized all the hassle that goes with gas self-launchers. When we get mature technology electric self-launchers, they'll dominate. Current complaints about electric sound exactly like the complaints about electric cars, before Tesla got it right.
So how big is the electric glider market vs. electric car market? Things get done with proper research and funding. I don't see that happen for the glider market. I suggest you review David's presentation. He discussed this point.

ICO glider engines have been developed over the last 70 years or so. And, then, many of them have come from the 2-cycle engine applications such as snowmobiles and ultralights. The electric glider market is much more immature..

That immaturity means they have a lot of promise, compared to the ICE gliders. We know in 5
years the performance of the electrics will increase significantly; the fossil fueled ones -
not nearly so much. Even at the current immature stage, they are so desirable, all the major
manufacturers, and some of the second tier, offer at least two electric models in mast or FES
varieties.

I suggest that in maybe 5, but certainly in 10 years, the discussions will no longer be about
gas vs electric, but which electric to buy.
--
Eric Greenwell - Washington State, USA (change ".netto" to ".us" to email me)
- "A Guide to Self-Launching Sailplane Operation"
lyhttps://sites.google.com/site/motorgliders/publications/download-the-guide-1

Wishful thinking duly noted. The development, deployment and long-term flight experience of aircraft takes time. Ten years is a good estimate for a single model such as the Antares. Its first flight was in 2003, so development must have started about 20 years ago. I think that in 5 to 10 years we will be thinking "Boy, those electric gliders looked promising at the time, but if we knew then what we know now I would never have bought one." Successful product development just can't be rushed.

For the moment the big limitation seems to me to be weight. I looked hard at the AS33 electric. You get one launch to 2000' and then 9000' of climb to get home. For that, it's really hard to get off the ground at less than 10 lbs/ft2 empty, and 10.5 in 15 m mode. Gas has a wonderful energy density. I'm surprised some sort of hybrid doesn't make sense, gas to recharge a smaller battery, then eliminate the drive elements with an electric motor. But I presume they worked the numbers on this.

John Cochrane BB

John Cochrane wrote on 3/3/2021 8:53 PM:
For the moment the big limitation seems to me to be weight. I looked hard at the AS33 electric. You get one launch to 2000' and then 9000' of climb to get home. For that, it's really hard to get off the ground at less than 10 lbs/ft2 empty, and 10.5 in 15 m mode. Gas has a wonderful energy density. I'm surprised some sort of hybrid doesn't make sense, gas to recharge a smaller battery, then eliminate the drive elements with an electric motor. But I presume they worked the numbers on this.

A hybrid system with a gas engine wouldn't have the pucker factor associated with starting a
gas powered motorglider to avoid a landing: if the hybrid engine doesn't start, it just means
your potential retrieve distance is shorter, instead of an imminent landing.

--
Eric Greenwell - Washington State, USA (change ".netto" to ".us" to email me)
- "A Guide to Self-Launching Sailplane Operation"
https://sites.google.com/site/motorg...ad-the-guide-1

A hybrid system with a gas engine wouldn't have the pucker factor associated with starting a
gas powered motorglider to avoid a landing: if the hybrid engine doesn't start, it just means
your potential retrieve distance is shorter, instead of an imminent landing.

I'll wade in here with some experience. Top Flight, a Boston startup specializing in hybrid propulsion systems, spend over half a decade developing their power unit. The hardest part for them was developing a unit which was reliable. Motors don't like vibration and they don't like heat. Combine the two together and the motor is not long for this world. It took a lot more R&D than anyone expected to make a lightweight package which could survive.

I would not expect anyone to be deploying this technology anytime soon. If and when it is commercialized, it will be useful for ferry flights of electric aircraft. For any use which requires permanent installation, you're probably better having it drive the propeller directly.

eGliders, I sense a tone here which is reminiscent of discussions about finally putting the 2-33 to rest. The US is no longer the forefront of light aviation, so we need to look east to see what the trends are. We know that leading glider manufacturers are racing to bring eGliders to market. A gentleman who works on glider competition rules noted this summer that glider records are falling left and right to eGliders. There is a growing group of amateurs who are pulling their engines out of their gas self-launchers and replacing them with electric (If you'd like to be a part of this group, DM me). The future was yesterday, but like any future it doesn't arrive at all places at once.

On Thursday, March 4, 2021 at 4:55:30 PM UTC-5, Kenn Sebesta wrote:
A hybrid system with a gas engine wouldn't have the pucker factor associated with starting a
gas powered motorglider to avoid a landing: if the hybrid engine doesn't start, it just means
your potential retrieve distance is shorter, instead of an imminent landing.
I'll wade in here with some experience. Top Flight, a Boston startup specializing in hybrid propulsion systems, spend over half a decade developing their power unit. The hardest part for them was developing a unit which was reliable. Motors don't like vibration and they don't like heat. Combine the two together and the motor is not long for this world. It took a lot more R&D than anyone expected to make a lightweight package which could survive..

I would not expect anyone to be deploying this technology anytime soon. If and when it is commercialized, it will be useful for ferry flights of electric aircraft. For any use which requires permanent installation, you're probably better having it drive the propeller directly.

eGliders, I sense a tone here which is reminiscent of discussions about finally putting the 2-33 to rest. The US is no longer the forefront of light aviation, so we need to look east to see what the trends are. We know that leading glider manufacturers are racing to bring eGliders to market. A gentleman who works on glider competition rules noted this summer that glider records are falling left and right to eGliders. There is a growing group of amateurs who are pulling their engines out of their gas self-launchers and replacing them with electric (If you'd like to be a part of this group, DM me). The future was yesterday, but like any future it doesn't arrive at all places at once.

What is contact info for the list mentioned?
Thx
UH

On Friday, March 5, 2021 at 8:00:05 AM UTC-5, Hank Nixon wrote:
On Thursday, March 4, 2021 at 4:55:30 PM UTC-5, Kenn Sebesta wrote:
... There is a growing group of amateurs who are pulling their engines out of their gas self-launchers and replacing them with electric (If you'd like to be a part of this group, DM me)...
What is contact info for the list mentioned?
Thx
UH

While Google Groups no longer displays email addresses, they can be pulled from RSS readers. I sent you an invite.

(Sometime in the near future I'll set up a better way to join the group.)

On Thursday, March 4, 2021 at 1:55:30 PM UTC-8, Kenn Sebesta wrote:
A hybrid system with a gas engine wouldn't have the pucker factor associated with starting a
gas powered motorglider to avoid a landing: if the hybrid engine doesn't start, it just means
your potential retrieve distance is shorter, instead of an imminent landing.
I'll wade in here with some experience. Top Flight, a Boston startup specializing in hybrid propulsion systems, spend over half a decade developing their power unit. The hardest part for them was developing a unit which was reliable. Motors don't like vibration and they don't like heat. Combine the two together and the motor is not long for this world. It took a lot more R&D than anyone expected to make a lightweight package which could survive..

I would not expect anyone to be deploying this technology anytime soon. If and when it is commercialized, it will be useful for ferry flights of electric aircraft. For any use which requires permanent installation, you're probably better having it drive the propeller directly.

eGliders, I sense a tone here which is reminiscent of discussions about finally putting the 2-33 to rest. The US is no longer the forefront of light aviation, so we need to look east to see what the trends are. We know that leading glider manufacturers are racing to bring eGliders to market. A gentleman who works on glider competition rules noted this summer that glider records are falling left and right to eGliders. There is a growing group of amateurs who are pulling their engines out of their gas self-launchers and replacing them with electric (If you'd like to be a part of this group, DM me). The future was yesterday, but like any future it doesn't arrive at all places at once.

Why don't you start by naming JUST ONE that replaced an ICE with an electric.

Tom

2G wrote on 3/7/2021 8:30 PM:
On Thursday, March 4, 2021 at 1:55:30 PM UTC-8, Kenn Sebesta wrote:
A hybrid system with a gas engine wouldn't have the pucker factor associated with starting a
gas powered motorglider to avoid a landing: if the hybrid engine doesn't start, it just means
your potential retrieve distance is shorter, instead of an imminent landing.
I'll wade in here with some experience. Top Flight, a Boston startup specializing in hybrid propulsion systems, spend over half a decade developing their power unit. The hardest part for them was developing a unit which was reliable. Motors don't like vibration and they don't like heat. Combine the two together and the motor is not long for this world. It took a lot more R&D than anyone expected to make a lightweight package which could survive..

I would not expect anyone to be deploying this technology anytime soon. If and when it is commercialized, it will be useful for ferry flights of electric aircraft. For any use which requires permanent installation, you're probably better having it drive the propeller directly.

eGliders, I sense a tone here which is reminiscent of discussions about finally putting the 2-33 to rest. The US is no longer the forefront of light aviation, so we need to look east to see what the trends are. We know that leading glider manufacturers are racing to bring eGliders to market. A gentleman who works on glider competition rules noted this summer that glider records are falling left and right to eGliders. There is a growing group of amateurs who are pulling their engines out of their gas self-launchers and replacing them with electric (If you'd like to be a part of this group, DM me). The future was yesterday, but like any future it doesn't arrive at all places at once.

Why don't you start by naming JUST ONE that replaced an ICE with an electric.

Tom

Hank Nixon.

--
Eric Greenwell - Washington State, USA (change ".netto" to ".us" to email me)
- "A Guide to Self-Launching Sailplane Operation"
https://sites.google.com/site/motorg...ad-the-guide-1

On 3/7/2021 11:30 PM, 2G wrote:
Why don't you start by naming JUST ONE that replaced an ICE with an electric.

Somehow I failed to post this earlier:
Patrick McLaughlin designed/built/debugged/delivered an electric
self-launch version of the Sparrowhawk some years ago (called the Owl).
Not a ICDE replacement, but a scratch-built pylon electric
self-launcher. Of course he's a bit more capable than most of us ;-)