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What is involved regulation wise adding an electric motor to a glider?



 
 
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  #61  
Old February 8th 21, 02:36 PM posted to rec.aviation.soaring
Dan Marotta
external usenet poster
 
Posts: 4,601
Default What is involved regulation wise adding an electric motor to aglider?

Can the glider chosen for this modification support an extra 100 lb in
the fuselage? If the batteries are carried in the wings, what's the
remaining weight of the non-lifting parts? Can the wings sustain the
extra bending load?

Dan
5J

On 2/7/21 1:30 PM, Hank Nixon wrote:
On Sunday, February 7, 2021 at 2:46:31 PM UTC-5, David Scott wrote:
On Friday, February 5, 2021 at 9:52:57 AM UTC-8, kinsell wrote:
On 2/2/21 6:09 PM, David Scott wrote:
On Tuesday, February 2, 2021 at 1:26:10 PM UTC-8, David Scott wrote:
I DON'T mean to stir up trouble on this forum with this question, especially being new, but have been wondering about this for some time. I am wondering how feasible it would be to do this with either a homebuilt or experimental glider here in the US?

I figure this has been asked but didn't find any threads on it.

Thank you for your responses. To be clear I don't have a sailplane but would like to get into the sport and the answers to this question would possibly affect what glider I would get. I am smart enough to get all my ducks in a row before doing anything, and this is the first I have talked about it. From an engineering standpoint, it doesn't look too difficult, navigating the regulations is where I expect the most trouble.


Putting together a motorglider is a strange path towards getting
involved with the sport. Might be better to take lessons, get the
rating, and have some time under your belt before taking on a project
like this.

In my local club, I see people going solo and maybe getting their
rating, and immediately thinking about buying a glider. This is with a
reasonable selection of under utilized club ships sitting around. I
encourage them to wait a couple years first.

If you're all set on owning an electric motorglider, there's a
reasonable selection of Silent 2 Electro's on W&W. Do yourself and the
owners a big favor and pick up one of those.

-Dave

In response to the first paragraph, I am more curious as to what my options would be IF my local club dissolves and tows are no longer available. I absolutely will get flying before doing anything else! The single place club gliders are 2 1-26s and a LET L-33, @$40hr. It sounds like none let you reach much of the areas soaring because of their low performance from club YouTube videos. Since my whole interest would be cross country, or the wave window south of Mt Hood, I will need to get access to a better glider than the club offers.

The Grasshopper has some very interesting aspects. It is the first articulated pylon I have seen, a design I have thought about quite a lot to get it tucked into the fuselage with the smallest opening possible. Designing it to be as compact as possible to fit as many gliders would be an obvious design criteria.

I do not want to reinvent the wheel, just make as few modifications as necessary for a different application. With this in mind electric paramotors are quite interesting. 110-120 lbs of thrust with 4ah batteries would be a good starting point, perhaps. I am not saying the cheapest versions are acceptable but the higher volume will bring the prices down. It looks like $5-$6k would buy the parts needed for a glider, plus the pylon assembly. A complete paramotor weighs around 65lbs so I figure this is close to what it would add to a glider, if done right. The biggest problem to an electric propulsion system is the batteries, and those are going to get vast improvements in the near future.


This is all just food for thought. To add more food I have a few questions. Let us use a 500lb 15 meter glider as the reference.

Any idea on how much thrust is need to sustain altitude?
How much thrust is needed to climb at 200 fpm? 300 fpm?


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


  #62  
Old February 8th 21, 02:55 PM posted to rec.aviation.soaring
Dan Marotta
external usenet poster
 
Posts: 4,601
Default What is involved regulation wise adding an electric motor to aglider?

Oops, should have read the entire thread before posting. JJ answered my
question perfectly.

Kenn's post was extremely informative.

Dan
5J

On 2/8/21 6:36 AM, Dan Marotta wrote:
Can the glider chosen for this modification support an extra 100 lb in
the fuselage?Â* If the batteries are carried in the wings, what's the
remaining weight of the non-lifting parts?Â* Can the wings sustain the
extra bending load?

Dan
5J

On 2/7/21 1:30 PM, Hank Nixon wrote:
On Sunday, February 7, 2021 at 2:46:31 PM UTC-5, David Scott wrote:
On Friday, February 5, 2021 at 9:52:57 AM UTC-8, kinsell wrote:
On 2/2/21 6:09 PM, David Scott wrote:
On Tuesday, February 2, 2021 at 1:26:10 PM UTC-8, David Scott wrote:
I DON'T mean to stir up trouble on this forum with this question,
especially being new, but have been wondering about this for some
time. I am wondering how feasible it would be to do this with
either a homebuilt or experimental glider here in the US?

I figure this has been asked but didn't find any threads on it.

Thank you for your responses. To be clear I don't have a sailplane
but would like to get into the sport and the answers to this
question would possibly affect what glider I would get. I am smart
enough to get all my ducks in a row before doing anything, and this
is the first I have talked about it. From an engineering
standpoint, it doesn't look too difficult, navigating the
regulations is where I expect the most trouble.


Putting together a motorglider is a strange path towards getting
involved with the sport. Might be better to take lessons, get the
rating, and have some time under your belt before taking on a project
like this.

In my local club, I see people going solo and maybe getting their
rating, and immediately thinking about buying a glider. This is with a
reasonable selection of under utilized club ships sitting around. I
encourage them to wait a couple years first.

If you're all set on owning an electric motorglider, there's a
reasonable selection of Silent 2 Electro's on W&W. Do yourself and the
owners a big favor and pick up one of those.

-Dave
In response to the first paragraph, I am more curious as to what my
options would be IF my local club dissolves and tows are no longer
available. I absolutely will get flying before doing anything else!
The single place club gliders are 2 1-26s and a LET L-33, @$40hr. It
sounds like none let you reach much of the areas soaring because of
their low performance from club YouTube videos. Since my whole
interest would be cross country, or the wave window south of Mt Hood,
I will need to get access to a better glider than the club offers.

The Grasshopper has some very interesting aspects. It is the first
articulated pylon I have seen, a design I have thought about quite a
lot to get it tucked into the fuselage with the smallest opening
possible. Designing it to be as compact as possible to fit as many
gliders would be an obvious design criteria.

I do not want to reinvent the wheel, just make as few modifications
as necessary for a different application. With this in mind electric
paramotors are quite interesting. 110-120 lbs of thrust with 4ah
batteries would be a good starting point, perhaps. I am not saying
the cheapest versions are acceptable but the higher volume will bring
the prices down. It looks like $5-$6k would buy the parts needed for
a glider, plus the pylon assembly. A complete paramotor weighs around
65lbs so I figure this is close to what it would add to a glider, if
done right. The biggest problem to an electric propulsion system is
the batteries, and those are going to get vast improvements in the
near future.


This is all just food for thought. To add more food I have a few
questions. Let us use a 500lb 15 meter glider as the reference.

Any idea on how much thrust is need to sustain altitude?
How much thrust is needed to climb at 200 fpm? 300 fpm?


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 ampsÂ* 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 theÂ* 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


  #63  
Old February 8th 21, 03:19 PM posted to rec.aviation.soaring
Hank Nixon
external usenet poster
 
Posts: 60
Default What is involved regulation wise adding an electric motor to a glider?

On Tuesday, February 2, 2021 at 6:43:09 PM UTC-5, 2G wrote:
On Tuesday, February 2, 2021 at 1:26:10 PM UTC-8, David Scott wrote:
I DON'T mean to stir up trouble on this forum with this question, especially being new, but have been wondering about this for some time. I am wondering how feasible it would be to do this with either a homebuilt or experimental glider here in the US?

I figure this has been asked but didn't find any threads on it.

I assume that you are talking about a glider registered experimental. The major obstacle beyond design, implementation and testing, is to get an AI to sign off on a conditional inspection. I would consult with that AI before you start modifying the glider. You may also have to hire a DAR (designated airworthiness representative). Again, doing this before modifying the glider is highly advisable. Another resource is the EAA. Look up this webinar (https://www.eaa.org/videos):
Webinar- Building an Aircraft - What You Need to Know
You will need to be an EAA member to watch it. Charlie Becker is the presenter and he is presumably building an electric glider, so he could be a great resource.

Tom

I was not able to find the webinar. Can you give a better guiding link?
Thx
UH
  #64  
Old February 8th 21, 03:27 PM posted to rec.aviation.soaring
Eric Greenwell[_4_]
external usenet poster
 
Posts: 1,939
Default What is involved regulation wise adding an electric motor to aglider?

Hank Nixon wrote on 2/8/2021 6:19 AM:
On Tuesday, February 2, 2021 at 6:43:09 PM UTC-5, 2G wrote:
On Tuesday, February 2, 2021 at 1:26:10 PM UTC-8, David Scott wrote:
I DON'T mean to stir up trouble on this forum with this question, especially being new, but have been wondering about this for some time. I am wondering how feasible it would be to do this with either a homebuilt or experimental glider here in the US?

I figure this has been asked but didn't find any threads on it.

I assume that you are talking about a glider registered experimental. The major obstacle beyond design, implementation and testing, is to get an AI to sign off on a conditional inspection. I would consult with that AI before you start modifying the glider. You may also have to hire a DAR (designated airworthiness representative). Again, doing this before modifying the glider is highly advisable. Another resource is the EAA. Look up this webinar (https://www.eaa.org/videos):
Webinar- Building an Aircraft - What You Need to Know
You will need to be an EAA member to watch it. Charlie Becker is the presenter and he is presumably building an electric glider, so he could be a great resource.

Tom

I was not able to find the webinar. Can you give a better guiding link?
Thx
UH

This works:
https://www.eaa.org/videos/6226408033001

--
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
  #65  
Old February 8th 21, 03:27 PM posted to rec.aviation.soaring
Hank Nixon
external usenet poster
 
Posts: 60
Default What is involved regulation wise adding an electric motor to a glider?


When I checked a year or so ago you had to go through their distributor in the US and they had to install it. I never checked but figured it would be in the $40k neighborhood. At least their distributor is close by here in Washington. I'm just outside of Hood River.



Who would this distributor be?
When I last communicated with Luka he made it clear that he was not going to be supplying conversion kits but did indicate the cost would be on the order of 30k euros. He has better things to do working with the established factories that have resident expertise and future demand.
UH
  #66  
Old February 8th 21, 04:29 PM posted to rec.aviation.soaring
Hank Nixon
external usenet poster
 
Posts: 60
Default What is involved regulation wise adding an electric motor to a glider?

On Monday, February 8, 2021 at 9:27:36 AM UTC-5, Eric Greenwell wrote:
Hank Nixon wrote on 2/8/2021 6:19 AM:
On Tuesday, February 2, 2021 at 6:43:09 PM UTC-5, 2G wrote:
On Tuesday, February 2, 2021 at 1:26:10 PM UTC-8, David Scott wrote:
I DON'T mean to stir up trouble on this forum with this question, especially being new, but have been wondering about this for some time. I am wondering how feasible it would be to do this with either a homebuilt or experimental glider here in the US?

I figure this has been asked but didn't find any threads on it.
I assume that you are talking about a glider registered experimental. The major obstacle beyond design, implementation and testing, is to get an AI to sign off on a conditional inspection. I would consult with that AI before you start modifying the glider. You may also have to hire a DAR (designated airworthiness representative). Again, doing this before modifying the glider is highly advisable. Another resource is the EAA. Look up this webinar (https://www.eaa.org/videos):
Webinar- Building an Aircraft - What You Need to Know
You will need to be an EAA member to watch it. Charlie Becker is the presenter and he is presumably building an electric glider, so he could be a great resource.

Tom

I was not able to find the webinar. Can you give a better guiding link?
Thx
UH

This works:
https://www.eaa.org/videos/6226408033001
--
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


Title for the video?
Thx
UH
  #67  
Old February 8th 21, 04:46 PM posted to rec.aviation.soaring
Eric Greenwell[_4_]
external usenet poster
 
Posts: 1,939
Default What is involved regulation wise adding an electric motor to aglider?

Hank Nixon wrote on 2/8/2021 7:29 AM:
On Monday, February 8, 2021 at 9:27:36 AM UTC-5, Eric Greenwell wrote:
Hank Nixon wrote on 2/8/2021 6:19 AM:
On Tuesday, February 2, 2021 at 6:43:09 PM UTC-5, 2G wrote:
On Tuesday, February 2, 2021 at 1:26:10 PM UTC-8, David Scott wrote:
I DON'T mean to stir up trouble on this forum with this question, especially being new, but have been wondering about this for some time. I am wondering how feasible it would be to do this with either a homebuilt or experimental glider here in the US?

I figure this has been asked but didn't find any threads on it.
I assume that you are talking about a glider registered experimental. The major obstacle beyond design, implementation and testing, is to get an AI to sign off on a conditional inspection. I would consult with that AI before you start modifying the glider. You may also have to hire a DAR (designated airworthiness representative). Again, doing this before modifying the glider is highly advisable. Another resource is the EAA. Look up this webinar (https://www.eaa.org/videos):
Webinar- Building an Aircraft - What You Need to Know
You will need to be an EAA member to watch it. Charlie Becker is the presenter and he is presumably building an electric glider, so he could be a great resource.

Tom
I was not able to find the webinar. Can you give a better guiding link?
Thx
UH

This works:
https://www.eaa.org/videos/6226408033001
--
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


Title for the video?
Thx
UH

"Webinar- Building an Aircraft - What You Need to Know"

The link takes me right to it, but it does require logging in as an EAA member to view it.

--
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
  #68  
Old February 8th 21, 07:20 PM posted to rec.aviation.soaring
David Scott
external usenet poster
 
Posts: 12
Default What is involved regulation wise adding an electric motor to a glider?

On Sunday, February 7, 2021 at 9:41:30 PM UTC-8, Nicholas Kennedy wrote:
David Scott
I don't know what your budget is.. But If you want to work on a electric glider a good choice might be to get a Antares.
From what I've read their very high performance, very nice to fly, but need ALOT of hands on work to keep them running.
Building something from scratch sounds very daunting to me.
JJ's post above is a eye opener.
Hanks posts are too. He's a full time professional in the Glider Biz, and look at the hurtles and challenges he had to overcome.
It seems to me you could easily spend a bunch of money, get in way over your head and end up with a very expensive, unflyable, unsafe, un airworthy, piece of junk.
Good Luck!
Nick
T

Nicholas, I am on the very low scale of budget now, which is why I am looking at the cheapest options, but expect the future will improve. To be clear, I will not cut up a good glider and not finish the project. Touching a glider would be the last part, after the power module is fully working and debugged on the bench. I fully understand it is not a small project. This really isn't a hard project there are many ways to accomplish it. I have embarked on bigger ones without knowing how to solve all of the problems involved, and failed at one. I have enough experience not to fail at a project like this.

John, this is something I have kept in mind. I am 165lbs dressed and can lose 10 with no problem, and should. I also think I could keep a power setup well under 100 lbs.

The FES distributor I found is indeed Blanik America.

Here is an interesting video showing the difference of a small prop vs a larger prop with gear reduction. Other than that the complete drive system is the same.
Small prop is 26kg of thrust @ 168 amps, large prop is 40kgs of thrust @ 138 amps. The video is https://www.youtube.com/watch?v=WgNMc35zqYo&t=154s..

Kenn, I PMed you about joining your Slack group, thank you. As for the drag of the pylon, yes, that is a big issue and one that going electric could really make a difference on. I think the unit that GP Gliders uses is the only one that tries to reduce the drag. The Grasshopper unit really fails in this regard, but wouldn't be hard to fix later on.

Thank you to J. and Kenn for the drag numbers, that is very informative. It looks like 110lbs of thrust would perhaps work pretty well. This is kind of the low end for electric paramotors and they don't operate on a streamlined pylon.

At the moment I am really liking the idea of a custom retractable pylon module and steal the rest from a paramotor to take advantage of their scale of economy and leverage what developments they make. This also means using a fixed 60" 2 blade propeller for improved efficiency. Or the closest I can get to match the motor used.

Hank, I already said I didn't think the FES system was viable for what I am looking for and fully understand why they would want nothing to do with it for the reasons you mention. As a machine shop I deal with it too. Thanks for the $$$$ info, looks like I was close but a little low.

Dan, seveal electric gliders store the batteries in the wings. I think the Antares does and know the GP Gliders do. I wonder how viable that would be for a retrofit? I also wonder how Antares and GP deal with thermal stability and fire control in the wings?
  #69  
Old February 8th 21, 09:02 PM posted to rec.aviation.soaring
John Sinclair[_5_]
external usenet poster
 
Posts: 88
Default What is involved regulation wise adding an electric motor to a glider?

Your reduced pilot weight (165+ 15 parachute) only reduces the fuselage load by 20 # below my LS-3a example, and that still leaves you something like 50# over the max allowable fuselage load. I’d nail down all these little problems before committing to the project..........you will find plenty of unforeseen issues that you haven’t even thought about.
I agree that a pylon motor mount is far superior to a FES, because there is no big CG issues to deal with. The FES nose motor weight must be counterbalanced with an aft battery which is located as far behind Your CG, as the nose motor is in front of the CG!
A big problem in selecting a ship to modify is the area you wish to install a pylon is the area where the wing controls are located on most ships.........ailerons, flaps and dive breaks......... need to come up with a plan on how to redesign the control linkage? BTW, installing a ballistic parachute shares this same problem........the chute and rocket need to go in the area where the wing controls are located.........?
I would think batteries located inside a wings D tube should be attached to the vertical shear web and strong enough to withstand a 5G load, none of which is taken by the wing skin? I’d place the batteries as far out in the wing as they will fit and you will need to design a way to get cooling air to all the battery cells. Make sure to properly repair any holes you cut in the D tube as that section takes some of the bending load and all of the twisting load seen by the wing!
What have I missed? Oh, how about a fire extinguisher......Inside the wing would be nice?
Have fun,
JJ




O
On Monday, February 8, 2021 at 10:20:20 AM UTC-8, David Scott wrote:
On Sunday, February 7, 2021 at 9:41:30 PM UTC-8, Nicholas Kennedy wrote:
David Scott
I don't know what your budget is.. But If you want to work on a electric glider a good choice might be to get a Antares.
From what I've read their very high performance, very nice to fly, but need ALOT of hands on work to keep them running.
Building something from scratch sounds very daunting to me.
JJ's post above is a eye opener.
Hanks posts are too. He's a full time professional in the Glider Biz, and look at the hurtles and challenges he had to overcome.
It seems to me you could easily spend a bunch of money, get in way over your head and end up with a very expensive, unflyable, unsafe, un airworthy, piece of junk.
Good Luck!
Nick
T

Nicholas, I am on the very low scale of budget now, which is why I am looking at the cheapest options, but expect the future will improve. To be clear, I will not cut up a good glider and not finish the project. Touching a glider would be the last part, after the power module is fully working and debugged on the bench. I fully understand it is not a small project. This really isn't a hard project there are many ways to accomplish it. I have embarked on bigger ones without knowing how to solve all of the problems involved, and failed at one. I have enough experience not to fail at a project like this.

John, this is something I have kept in mind. I am 165lbs dressed and can lose 10 with no problem, and should. I also think I could keep a power setup well under 100 lbs.

The FES distributor I found is indeed Blanik America.

Here is an interesting video showing the difference of a small prop vs a larger prop with gear reduction. Other than that the complete drive system is the same.
Small prop is 26kg of thrust @ 168 amps, large prop is 40kgs of thrust @ 138 amps. The video is https://www.youtube.com/watch?v=WgNMc35zqYo&t=154s.

Kenn, I PMed you about joining your Slack group, thank you. As for the drag of the pylon, yes, that is a big issue and one that going electric could really make a difference on. I think the unit that GP Gliders uses is the only one that tries to reduce the drag. The Grasshopper unit really fails in this regard, but wouldn't be hard to fix later on.

Thank you to J. and Kenn for the drag numbers, that is very informative. It looks like 110lbs of thrust would perhaps work pretty well. This is kind of the low end for electric paramotors and they don't operate on a streamlined pylon.

At the moment I am really liking the idea of a custom retractable pylon module and steal the rest from a paramotor to take advantage of their scale of economy and leverage what developments they make. This also means using a fixed 60" 2 blade propeller for improved efficiency. Or the closest I can get to match the motor used.

Hank, I already said I didn't think the FES system was viable for what I am looking for and fully understand why they would want nothing to do with it for the reasons you mention. As a machine shop I deal with it too. Thanks for the $$$$ info, looks like I was close but a little low.

Dan, seveal electric gliders store the batteries in the wings. I think the Antares does and know the GP Gliders do. I wonder how viable that would be for a retrofit? I also wonder how Antares and GP deal with thermal stability and fire control in the wings?

  #70  
Old February 8th 21, 09:22 PM posted to rec.aviation.soaring
Dan Marotta
external usenet poster
 
Posts: 4,601
Default What is involved regulation wise adding an electric motor to aglider?

I spoke with Luka about 5 years ago about installing FES in my LAK-17a.
There are plenty of very competent folks at Moriarty to do the work, but
Luka was firm that only he and his people would do it. He said that for
roughly $25K each for a minimum of 4 gliders, plus travel and living
expenses, they'd come to the US and do the work. I got a Stemme, instead.

Dan
5J

On 2/8/21 11:20 AM, David Scott wrote:
On Sunday, February 7, 2021 at 9:41:30 PM UTC-8, Nicholas Kennedy wrote:
David Scott
I don't know what your budget is.. But If you want to work on a electric glider a good choice might be to get a Antares.
From what I've read their very high performance, very nice to fly, but need ALOT of hands on work to keep them running.
Building something from scratch sounds very daunting to me.
JJ's post above is a eye opener.
Hanks posts are too. He's a full time professional in the Glider Biz, and look at the hurtles and challenges he had to overcome.
It seems to me you could easily spend a bunch of money, get in way over your head and end up with a very expensive, unflyable, unsafe, un airworthy, piece of junk.
Good Luck!
Nick
T

Nicholas, I am on the very low scale of budget now, which is why I am looking at the cheapest options, but expect the future will improve. To be clear, I will not cut up a good glider and not finish the project. Touching a glider would be the last part, after the power module is fully working and debugged on the bench. I fully understand it is not a small project. This really isn't a hard project there are many ways to accomplish it. I have embarked on bigger ones without knowing how to solve all of the problems involved, and failed at one. I have enough experience not to fail at a project like this.

John, this is something I have kept in mind. I am 165lbs dressed and can lose 10 with no problem, and should. I also think I could keep a power setup well under 100 lbs.

The FES distributor I found is indeed Blanik America.

Here is an interesting video showing the difference of a small prop vs a larger prop with gear reduction. Other than that the complete drive system is the same.
Small prop is 26kg of thrust @ 168 amps, large prop is 40kgs of thrust @ 138 amps. The video is https://www.youtube.com/watch?v=WgNMc35zqYo&t=154s.

Kenn, I PMed you about joining your Slack group, thank you. As for the drag of the pylon, yes, that is a big issue and one that going electric could really make a difference on. I think the unit that GP Gliders uses is the only one that tries to reduce the drag. The Grasshopper unit really fails in this regard, but wouldn't be hard to fix later on.

Thank you to J. and Kenn for the drag numbers, that is very informative. It looks like 110lbs of thrust would perhaps work pretty well. This is kind of the low end for electric paramotors and they don't operate on a streamlined pylon.

At the moment I am really liking the idea of a custom retractable pylon module and steal the rest from a paramotor to take advantage of their scale of economy and leverage what developments they make. This also means using a fixed 60" 2 blade propeller for improved efficiency. Or the closest I can get to match the motor used.

Hank, I already said I didn't think the FES system was viable for what I am looking for and fully understand why they would want nothing to do with it for the reasons you mention. As a machine shop I deal with it too. Thanks for the $$$$ info, looks like I was close but a little low.

Dan, seveal electric gliders store the batteries in the wings. I think the Antares does and know the GP Gliders do. I wonder how viable that would be for a retrofit? I also wonder how Antares and GP deal with thermal stability and fire control in the wings?

 




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