Front Electric Sustainer

First flight of Front Electric Sustainer - FES

http://www.front-electric-sustainer.com

http://www.youtube.com/watch?v=TNOKq6PKIvM

Regards,

Luka Znidarsic

On Nov 1, 1:49*am, LimaZulu wrote:
First flight of Front Electric Sustainer - FES

http://www.front-electric-sustainer.com

http://www.youtube.com/watch?v=TNOKq6PKIvM

Regards,

Luka Znidarsic

If I read the specs right you can operate at full power for 14.4
minutes over which time you can climb a bit over 4,300 feet. How's
that compare to other sustainers? This seems simpler than most other
configurations which is nice.

9B

I was wondering when someone would use the motor and folding prop used
on the Radian RC sailplane on a full scale ship. Nice, motor weight in
nose is balanced with battery weight aft and only 77 pounds total. I
figure 75 miles at low power or 5700 foot climb at full power. Heat
from running motor could warm your feet on a cold winter day! Any idea
on retrofit price and availability?
JJ

On Nov 1, 4:29*am, Andy wrote:
On Nov 1, 1:49*am, LimaZulu wrote:

First flight of Front Electric Sustainer - FES

http://www.front-electric-sustainer.com

http://www.youtube.com/watch?v=TNOKq6PKIvM

Regards,

Luka Znidarsic

If I read the specs right you can operate at full power for 14.4
minutes over which time you can climb a bit over 4,300 feet. *How's
that compare to other sustainers? *This seems simpler than most other
configurations which is nice.

9B

It would be interestingly they claim level flight for 120km which is
greater distance than a 4,300' climb will normally allow you to glide.
Just plucking numbers out of thin air of 50 knots for optimal climb
and cruise speeds (I expect climb would be slower) and an L/D of 50:1.
You would travel 22 km in the climb and glide 65km for a total of
87km. It would require a L/D 74 to match the straight cruise. The
exact optimal speeds and the profile of the climb as battery power
diminishes likely affects all this.

Looks like nice packaging. I am curious as well what happens to the
forward air cockpit air vent, nose pitot tube, nose tow hook, and
where cooling air for the engine comes from (presumably the nose
hole). At 95% efficiency the 15kW motor will generate 750W.

Darryl

On Nov 1, 7:07*am, Darryl Ramm wrote:
On Nov 1, 4:29*am, Andy wrote:





On Nov 1, 1:49*am, LimaZulu wrote:

First flight of Front Electric Sustainer - FES

http://www.front-electric-sustainer.com

http://www.youtube.com/watch?v=TNOKq6PKIvM

Regards,

Luka Znidarsic

If I read the specs right you can operate at full power for 14.4
minutes over which time you can climb a bit over 4,300 feet. *How's
that compare to other sustainers? *This seems simpler than most other
configurations which is nice.

9B

It would be interestingly they claim level flight for 120km which is
greater distance than a 4,300' climb will normally allow you to glide.
Just plucking numbers out of thin air of 50 knots for optimal climb
and cruise speeds (I expect climb would be slower) and an L/D of 50:1.
You would travel 22 km in the climb and glide 65km for a total of
87km. It would require a L/D 74 to match the straight cruise. The
exact optimal speeds and the profile of the climb as battery power
diminishes likely affects all this.

Looks like nice packaging. I am curious as well what happens to the
forward air cockpit air vent, nose pitot tube, nose tow hook, and
where cooling air for the engine comes from (presumably the nose
hole). At 95% efficiency the 15kW motor will generate 750W.

Darryl- Hide quoted text -

- Show quoted text -
JJ, I've wondered the same thing too. Seems too simple NOT to do.
What I want to know is this: When is China going to start cranking
out cheap brushless motors in the 15 - 50 Kw range (5Kw increments
will do nicely, thank you)? It's inevitable, but I'm impatient. I'd
like my electric motorcycle, 'round town car, and self launcher sooner
rather than later.

Uncle Fuzzy wrote:
On Nov 1, 7:07 am, Darryl Ramm wrote:
On Nov 1, 4:29 am, Andy wrote:

It would be interestingly they claim level flight for 120km which is
greater distance than a 4,300' climb will normally allow you to glide.
Just plucking numbers out of thin air of 50 knots for optimal climb
and cruise speeds (I expect climb would be slower) and an L/D of 50:1.
You would travel 22 km in the climb and glide 65km for a total of
87km. It would require a L/D 74 to match the straight cruise. The
exact optimal speeds and the profile of the climb as battery power
diminishes likely affects all this.

A nice side effect, running on electric power, is that you probably
won't have to use the common "saw tooth" technique that you adopt on
combustion engine SSG:s running full throttle.

An electrical engine with engine control can easily be used to run on
half power, making saw toothing unnecessary. That said, the engine
control system must not have excessive loss running partial throttle.

This used to be a problem in electrical model aircraft control circuits.
With todays speed controls this is usually no longer a problem.

I would like to have the batteries in my wings though. The idea of
having a solid block of metal/lithium/what not behind my back in a crash
is a bit scary. But I guess at these weights its not worse than having
your average Solo behind you.

But if I would wish, that would be my option.

Having flown electric model aircrafts since about 1983-1984, I give a
standing ovation to this and other electrical SSG/SLG solutions coming
out of various manufacturers.

Look at model aircrafts, today most starts to fly with electric power.
Back in 1980'ies others laughed at you, claiming it was never going to
be big. If we look 10-20 years ahead I think no-one will choose a
combustion engine over an electrical in a new glider.

We will now also be able to benefit from all money being plowed down on
battery technology in the car industry.

I have high hopes for the future going electric, it fits so nice with
our beloved sport.

Go-go,
Anders P

On Nov 1, 1:49*am, LimaZulu wrote:
First flight of Front Electric Sustainer - FES

http://www.front-electric-sustainer.com

http://www.youtube.com/watch?v=TNOKq6PKIvM

Regards,

Luka Znidarsic

I've got an empty engine bay in my Apis, always thought an electric
motor would be a nice thing to put in there. The doors for the prop
can handle a 46" dia. blade.

Brad

AndersP wrote:
I would like to have the batteries in my wings though. The idea of
having a solid block of metal/lithium/what not behind my back in a
crash is a bit scary. But I guess at these weights its not worse than
having your average Solo behind you.

But if I would wish, that would be my option.
A self-launcher, like my ASH 26 E or a DG 800, has about 130 pounds of
metal behind you, plus another 30 pounds of fuel. It doesn't seem to be
a problem.

I think it is probably better to have the 50 pounds of batteries in the
fuselage than in the wings, where it is easier to remove them, and they
don't have to be connected each time the glider is rigged. The design
problem for retrofitting will be the loss of allowed cockpit weight.
Newer gliders, that are already designed for two stroke sustainers, will
have enough "non-lifting parts" weight allowance so that adding the
electric system will not diminish their allowed cockpit weight.

Judging by the information on the website, it looks like a very well
done solution for a sustainer equipped glider.

--
Eric Greenwell - Washington State, USA
* Change "netto" to "net" to email me directly

* "A Guide to Self-launching Sailplane Operation" at www.motorglider.org

This looks like a natural for a single blade prop, folding flush into
a contoured recess in the bottom of the nose.

I like it!

Kirk

On 1 nov., 17:07, Darryl Ramm wrote:
On Nov 1, 4:29*am, Andy wrote:



On Nov 1, 1:49*am, LimaZulu wrote:

First flight of Front Electric Sustainer - FES

http://www.front-electric-sustainer.com

http://www.youtube.com/watch?v=TNOKq6PKIvM

Regards,

Luka Znidarsic

If I read the specs right you can operate at full power for 14.4
minutes over which time you can climb a bit over 4,300 feet. *How's
that compare to other sustainers? *This seems simpler than most other
configurations which is nice.

9B

It would be interestingly they claim level flight for 120km which is
greater distance than a 4,300' climb will normally allow you to glide.
Just plucking numbers out of thin air of 50 knots for optimal climb
and cruise speeds (I expect climb would be slower) and an L/D of 50:1.
You would travel 22 km in the climb and glide 65km for a total of
87km. It would require a L/D 74 to match the straight cruise. The
exact optimal speeds and the profile of the climb as battery power
diminishes likely affects all this.

Looks like nice packaging. I am curious as well what happens to the
forward air cockpit air vent, nose pitot tube, nose tow hook, and
where cooling air for the engine comes from (presumably the nose
hole). At 95% efficiency the 15kW motor will generate 750W.

Darryl

Dear Darryl,

Data published are pesimistic version of calculated values. For real
data we must do more flights in calm conditions.
-Forward cockpit air vent is still used, air just goes also trought
the motor to cool the engine. And will be possible to close it during
gliding, but must be opened when engine is running
-Nose pitot tube is replaced with fin tube otherwise used for TE (TE
compensation tube was replaced with electronic compensation, and same
hole used as pitot). Flight test shows that this works just fine, as
airspeed is correct.
-LAK17a has front tow hook placed bellow instrument panel
-95% is efficiency of motor+controler. Motor have good cooling, and it
not looks that heating will be a problem. It is just warm and
controler is rated for much higher power and is not even warm.

regards,

Luka