$1 billion BMS Ooops...

I just gotta ask, "Why"?

What is the cost of the conversion? Is the engine failed and not
repairable? Are there a lot of brownie points for "saving the planet"?

If I wanted to, my gas powered Stemme could reach just about anywhere in
the western states on a single tank of gas. The electric offerings from
Stemme have great range at the expense of carrying a gas-powered
generator along to make the electric power to run the motor. Where's
the advantage?

Dan
5J

On 3/8/21 8:51 PM, Eric Greenwell wrote:
2G wrote on 3/8/2021 5:19 PM:
On Monday, March 8, 2021 at 5:15:13 PM UTC-8, 2G wrote:
On Monday, March 8, 2021 at 5:25:41 AM UTC-8, Eric Greenwell wrote:
2G wrote on 3/7/2021 9:06 PM:
On Sunday, March 7, 2021 at 8:52:23 PM UTC-8, Eric Greenwell wrote:
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

And what was the glider?

Hank has posted about the glider a number of times on RAS. Search
for "Nixon", or look in the
thread "What is involved regulation wise adding an electric motor to
a glider?" Here is are
some details from Hank:

Some data from first hand experience:
ASW-24E converted to electric from 2 cycle Rotax gas.
Power system including all items is right at 100 lb added to pure
sailplane airframe weight.
This is a pylon mounted retractable system.
Battery is 120 volt,4.9 kwh lithium ion weighing 60 lb.
Climb rate at 160 amps is 300 ft/minute. Actual power delivered is
about 16kw.
Climb rate at 230 amps is 500 ft/minute. Actual power delivered is
about 23kw at this time
Your cost estimate is a bit less than1/2 what it would require for
parts, not including items
required to do the airframe conversion and assuming the person doing
this can fabricate
required items, engineer and wire the system, design and construct
the prop, etc.
This assumes perfect efficiency and nothing destroyed or scrapped
going through the learning
process. Of those I am aware of that have done ,or are doing this,
nobody has had that good
fortune.
FWIW
UH
--
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

This glider was converted from a sustainer to a self-launcher,
apparently to provide a capability it did not have before and not
because the engine did not perform as intended.

Tom

Also, Hank concluded with this piece of advice:

"To my knowledge this has been done once so far in the US .
If you want an electric sailplane- buy one."

Sounds prudent to me.

Some people like the challenge, much as glider pilots do in their flying
(or they'd get an airplane): Ken Sebesta, a participant here, has
removed the self-launching gas motor from his AC-5 Russia and is
replacing it with an electric motor. I believe he's bench-tested the
motor, ESC, and batteries, and is now working out the motor mounting
details.

Dan Marotta wrote on 3/9/2021 7:42 AM:
I just gotta ask, "Why"?

What is the cost of the conversion?* Is the engine failed and not repairable? Are there a lot
of brownie points for "saving the planet"?

If I wanted to, my gas powered Stemme could reach just about anywhere in the western states on
a single tank of gas.* The electric offerings from Stemme have great range at the expense of
carrying a gas-powered generator along to make the electric power to run the motor.* Where's
the advantage?

Dan
Don't take it personally :^) Kenn is converting an AC-5 Russia, a WAY DIFFERENT glider than the
Stemme! It has a rattlely, unreliable motor of modest power, but I'll let Kenn fill in the details
of his decision.

On 3/8/21 8:51 PM, Eric Greenwell wrote:
2G wrote on 3/8/2021 5:19 PM:
On Monday, March 8, 2021 at 5:15:13 PM UTC-8, 2G wrote:
On Monday, March 8, 2021 at 5:25:41 AM UTC-8, Eric Greenwell wrote:
2G wrote on 3/7/2021 9:06 PM:
On Sunday, March 7, 2021 at 8:52:23 PM UTC-8, Eric Greenwell wrote:
...

Also, Hank concluded with this piece of advice:

"To my knowledge this has been done once so far in the US .
If you want an electric sailplane- buy one."

Sounds prudent to me.

Some people like the challenge, much as glider pilots do in their flying (or they'd get an
airplane): Ken Sebesta, a participant here, has removed the self-launching gas motor from his
AC-5 Russia and is replacing it with an electric motor. I believe he's bench-tested the
motor, ESC, and batteries, and is now working out the motor mounting details.




--
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

I don't take anything on RAS personally any more. I was genuinely
interested in the "why" aspect of the conversion.

Dan
5J

On 3/9/21 12:25 PM, Eric Greenwell wrote:

Dan Marotta wrote on 3/9/2021 7:42 AM:
I just gotta ask, "Why"?

What is the cost of the conversion?Â* Is the engine failed and not
repairable? Are there a lot of brownie points for "saving the planet"?

If I wanted to, my gas powered Stemme could reach just about anywhere
in the western states on a single tank of gas.Â* The electric offerings
from Stemme have great range at the expense of carrying a gas-powered
generator along to make the electric power to run the motor.Â* Where's
the advantage?

Dan
Don't take it personally :^) Kenn is converting an AC-5 Russia, a WAY
DIFFERENT glider than the
Stemme! It has a rattlely, unreliable motor of modest power, but I'll
let Kenn fill in the details
of his decision.

On 3/8/21 8:51 PM, Eric Greenwell wrote:
2G wrote on 3/8/2021 5:19 PM:
On Monday, March 8, 2021 at 5:15:13 PM UTC-8, 2G wrote:
On Monday, March 8, 2021 at 5:25:41 AM UTC-8, Eric Greenwell wrote:
2G wrote on 3/7/2021 9:06 PM:
On Sunday, March 7, 2021 at 8:52:23 PM UTC-8, Eric Greenwell wrote:
...

Also, Hank concluded with this piece of advice:

"To my knowledge this has been done once so far in the US .
If you want an electric sailplane- buy one."

Sounds prudent to me.

Some people like the challenge, much as glider pilots do in their
flying (or they'd get an airplane): Ken Sebesta, a participant here,
has removed the self-launching gas motor from his AC-5 Russia and is
replacing it with an electric motor. I believe he's bench-tested the
motor, ESC, and batteries, and is now working out the motor mounting
details.