Electric Self Launch System

[Emir Sherbi]

Hi everyone,

My name is Emir Sherbi, i'm a mechanical engineer from Argentina. With a partner who is an electronic engineer we've designed an electric self launching system that can be retrofitted in most of the composite sailplanes. Some of you may be saw my booth in the SSA convention in Reno with the mockup of the prototype.
The idea is to sell it as a kit so you don't have to ship the glider to my country. The modifications to be made are very simple. Any repair shop have enough knowledge to do it.
These are the links for who are interested in following the project.

https://www.instagram.com/grasshoppersystem/
https://www.facebook.com/charlysierragolf/

Kindest Regards

[2G]

On Monday, June 4, 2018 at 9:09:00 AM UTC-7, Emir Sherbi wrote:
> Hi everyone,
>
> My name is Emir Sherbi, i'm a mechanical engineer from Argentina. With a partner who is an electronic engineer we've designed an electric self launching system that can be retrofitted in most of the composite sailplanes. Some of you may be saw my booth in the SSA convention in Reno with the mockup of the prototype.
> The idea is to sell it as a kit so you don't have to ship the glider to my country. The modifications to be made are very simple. Any repair shop have enough knowledge to do it.
> These are the links for who are interested in following the project.
>
> https://www.instagram.com/grasshoppersystem/
> https://www.facebook.com/charlysierragolf/
>
> Kindest Regards

When I stopped by your booth, you indicated that this system is still in development with much work left to be done. Is this accurate?

Tom

[Emir Sherbi]

El jueves, 7 de junio de 2018, 20:41:10 (UTC-3), 2G escribió:
> On Monday, June 4, 2018 at 9:09:00 AM UTC-7, Emir Sherbi wrote:
> > Hi everyone,
> >
> > My name is Emir Sherbi, i'm a mechanical engineer from Argentina. With a partner who is an electronic engineer we've designed an electric self launching system that can be retrofitted in most of the composite sailplanes. Some of you may be saw my booth in the SSA convention in Reno with the mockup of the prototype.
> > The idea is to sell it as a kit so you don't have to ship the glider to my country. The modifications to be made are very simple. Any repair shop have enough knowledge to do it.
> > These are the links for who are interested in following the project.
> >
> > https://www.instagram.com/grasshoppersystem/
> > https://www.facebook.com/charlysierragolf/
> >
> > Kindest Regards
>
> When I stopped by your booth, you indicated that this system is still in development with much work left to be done. Is this accurate?
>
> Tom

Hi Tom


The most difficult part that we are working on is the battery pack supplier and testing. In other hand we also are starting to build our own motors, not only for this application but also for another types of vehicles (mostly agricultural). But for the US clients we can supply any already known motor brand to power the kit.
As you can see on the pages that i shared, we are starting to work on the fuselage. The pylon is on its final revision for flight testing but we are still working on the batteries.

Regards

[2G]

On Friday, June 8, 2018 at 6:51:52 AM UTC-7, Emir Sherbi wrote:
> El jueves, 7 de junio de 2018, 20:41:10 (UTC-3), 2G escribió:
> > On Monday, June 4, 2018 at 9:09:00 AM UTC-7, Emir Sherbi wrote:
> > > Hi everyone,
> > >
> > > My name is Emir Sherbi, i'm a mechanical engineer from Argentina. With a partner who is an electronic engineer we've designed an electric self launching system that can be retrofitted in most of the composite sailplanes.. Some of you may be saw my booth in the SSA convention in Reno with the mockup of the prototype.
> > > The idea is to sell it as a kit so you don't have to ship the glider to my country. The modifications to be made are very simple. Any repair shop have enough knowledge to do it.
> > > These are the links for who are interested in following the project.
> > >
> > > https://www.instagram.com/grasshoppersystem/
> > > https://www.facebook.com/charlysierragolf/
> > >
> > > Kindest Regards
> >
> > When I stopped by your booth, you indicated that this system is still in development with much work left to be done. Is this accurate?
> >
> > Tom
>
> Hi Tom
>
>
> The most difficult part that we are working on is the battery pack supplier and testing. In other hand we also are starting to build our own motors, not only for this application but also for another types of vehicles (mostly agricultural). But for the US clients we can supply any already known motor brand to power the kit.
> As you can see on the pages that i shared, we are starting to work on the fuselage. The pylon is on its final revision for flight testing but we are still working on the batteries.
>
> Regards

Which battery chemistry are you going to use?

Tom

[Emir Sherbi]

El viernes, 8 de junio de 2018, 16:59:09 (UTC-3), 2G escribió:
> On Friday, June 8, 2018 at 6:51:52 AM UTC-7, Emir Sherbi wrote:
> > El jueves, 7 de junio de 2018, 20:41:10 (UTC-3), 2G escribió:
> > > On Monday, June 4, 2018 at 9:09:00 AM UTC-7, Emir Sherbi wrote:
> > > > Hi everyone,
> > > >
> > > > My name is Emir Sherbi, i'm a mechanical engineer from Argentina. With a partner who is an electronic engineer we've designed an electric self launching system that can be retrofitted in most of the composite sailplanes. Some of you may be saw my booth in the SSA convention in Reno with the mockup of the prototype.
> > > > The idea is to sell it as a kit so you don't have to ship the glider to my country. The modifications to be made are very simple. Any repair shop have enough knowledge to do it.
> > > > These are the links for who are interested in following the project..
> > > >
> > > > https://www.instagram.com/grasshoppersystem/
> > > > https://www.facebook.com/charlysierragolf/
> > > >
> > > > Kindest Regards
> > >
> > > When I stopped by your booth, you indicated that this system is still in development with much work left to be done. Is this accurate?
> > >
> > > Tom
> >
> > Hi Tom
> >
> >
> > The most difficult part that we are working on is the battery pack supplier and testing. In other hand we also are starting to build our own motors, not only for this application but also for another types of vehicles (mostly agricultural). But for the US clients we can supply any already known motor brand to power the kit.
> > As you can see on the pages that i shared, we are starting to work on the fuselage. The pylon is on its final revision for flight testing but we are still working on the batteries.
> >
> > Regards
>
> Which battery chemistry are you going to use?
>
> Tom



INR and IMR, depending on the flight mission.

Regards

[son_of_flubber]

On Friday, June 8, 2018 at 4:50:33 PM UTC-4, Emir Sherbi wrote:

> INR and IMR, depending on the flight mission.


https://breazy.com/products/samsung-inr18650-25r-2500mah

INR 18650 2500mah Battery (2 Pack) - Samsung

20 amps of continous discharge, the Samsung 25r has been the go to battery for most vapers because of its authenticity and its transparent rating system. In terms of cell degradation the Samsung 25r has been a reliable source of power.

[[email protected]]

On Friday, June 8, 2018 at 6:30:29 PM UTC-5, son_of_flubber wrote:
> On Friday, June 8, 2018 at 4:50:33 PM UTC-4, Emir Sherbi wrote:
>
> > INR and IMR, depending on the flight mission.
>
>
> https://breazy.com/products/samsung-inr18650-25r-2500mah
>
> INR 18650 2500mah Battery (2 Pack) - Samsung
>
> 20 amps of continous discharge, the Samsung 25r has been the go to battery for most vapers because of its authenticity and its transparent rating system. In terms of cell degradation the Samsung 25r has been a reliable source of power.

Flub, are you implying this project is vapor ware?

[son_of_flubber]

On Friday, June 8, 2018 at 8:28:04 PM UTC-4, wrote:

> Flub, are you implying this project is vapor ware?

Not at all. I think it is brilliant that millions of vapers have volunteered to do rapid discharge testing of INR battery technology. And a mass market battery like this should benefit from manufacturing economies of scale and competition.

[Charlie M. (UH & 002 owner/pilot)]

Interesting additional battery chemistry info.....

https://batterybro.com/blogs/18650-wholesale-battery-reviews/18880255-battery-chemistry-finally-explained

[Emir Sherbi]

El lunes, 4 de junio de 2018, 13:09:00 (UTC-3), Emir Sherbi escribió:
> Hi everyone,
>
> My name is Emir Sherbi, i'm a mechanical engineer from Argentina. With a partner who is an electronic engineer we've designed an electric self launching system that can be retrofitted in most of the composite sailplanes. Some of you may be saw my booth in the SSA convention in Reno with the mockup of the prototype.
> The idea is to sell it as a kit so you don't have to ship the glider to my country. The modifications to be made are very simple. Any repair shop have enough knowledge to do it.
> These are the links for who are interested in following the project.
>
> https://www.instagram.com/grasshoppersystem/
> https://www.facebook.com/charlysierragolf/
>
> Kindest Regards

Hello,

This is another update with the work done today.

https://www.instagram.com/grasshoppersystem/
https://www.facebook.com/charlysierragolf/

[2G]

On Friday, June 8, 2018 at 6:30:32 PM UTC-7, Charlie M. (UH & 002 owner/pilot) wrote:
> Interesting additional battery chemistry info.....
>
> https://batterybro.com/blogs/18650-wholesale-battery-reviews/18880255-battery-chemistry-finally-explained

And here is a lot more detailed info:

http://batteryuniversity.com/learn/article/types_of_lithium_ion

While the safety of IMR and INR are good, they are not as good as LFP.

Tom

[Emir Sherbi]

Yes, they are very reliable and stable. They have very long life cycle. But the energy density is lower. For the same capacity you have to think in more than 60% of weight increase.

[son_of_flubber]

On Saturday, June 9, 2018 at 11:54:06 PM UTC-4, Emir Sherbi wrote:
> Yes, they are very reliable and stable. They have very long life cycle. But the energy density is lower. For the same capacity you have to think in more than 60% of weight increase.

I'd be very happy to have something soon that could sustain 30 minutes of flight at best glide speed. Maybe I'd upgrade to self-launch later when higher energy density batteries become available, but maybe not.

The 'best' is the enemy of the 'good enough'.

Having learned my lesson with Betamax, I'm looking for the VHS of electric propulsion. My glider is 20 years old. There is a limit to how much I want to sink into it.

[[email protected]]

"I'm looking for the VHS of electric propulsion."
And we wonder why we're decades behind the Europeans...

[Emir Sherbi]

El domingo, 10 de junio de 2018, 21:30:15 (UTC-3), son_of_flubber escribió:
> On Saturday, June 9, 2018 at 11:54:06 PM UTC-4, Emir Sherbi wrote:
> > Yes, they are very reliable and stable. They have very long life cycle. But the energy density is lower. For the same capacity you have to think in more than 60% of weight increase.
>
> I'd be very happy to have something soon that could sustain 30 minutes of flight at best glide speed. Maybe I'd upgrade to self-launch later when higher energy density batteries become available, but maybe not.
>
> The 'best' is the enemy of the 'good enough'.
>
> Having learned my lesson with Betamax, I'm looking for the VHS of electric propulsion. My glider is 20 years old. There is a limit to how much I want to sink into it.

For our design, having only 30 minutes of sustained flight or selflaunch and having 1 hour of sustained flight is the same technological challenge.
The only thing that changes is the final price.

20 years old is like new, we are about to install it on a 35 years old Pegasus.

[Charlie Quebec]

Yeh, waiting for an inferior quality system that is more popular is a very US approach.

[son_of_flubber]

On Sunday, June 10, 2018 at 10:49:51 PM UTC-4, Emir Sherbi wrote:

>For the same capacity you have to think in more than 60% of weight increase.

A lower capacity battery pack will be lighter and cheaper. Maybe that would make INR batteries feasible.

[kinsell]

On 06/11/2018 06:37 AM, son_of_flubber wrote:
> On Sunday, June 10, 2018 at 10:49:51 PM UTC-4, Emir Sherbi wrote:
>
>> For the same capacity you have to think in more than 60% of weight increase.
>
> A lower capacity battery pack will be lighter and cheaper. Maybe that would make INR batteries feasible.
>

I think he was talking about LFP batteries not being feasible, due to
low energy density.

[Emir Sherbi]

El lunes, 11 de junio de 2018, 9:37:44 (UTC-3), son_of_flubber escribió:
> On Sunday, June 10, 2018 at 10:49:51 PM UTC-4, Emir Sherbi wrote:
>
> >For the same capacity you have to think in more than 60% of weight increase.
>
> A lower capacity battery pack will be lighter and cheaper. Maybe that would make INR batteries feasible.


In your case if you want that capabilities it can be arranged.
We are trying to standardize some components but the battery size and shape can be changed without much issues.

[[email protected]]

On Friday, June 8, 2018 at 7:30:29 PM UTC-4, son_of_flubber wrote:
> On Friday, June 8, 2018 at 4:50:33 PM UTC-4, Emir Sherbi wrote:
>
> > INR and IMR, depending on the flight mission.
>
>
> https://breazy.com/products/samsung-inr18650-25r-2500mah
>
> INR 18650 2500mah Battery (2 Pack) - Samsung
>
> 20 amps of continous discharge, the Samsung 25r has been the go to battery for most vapers because of its authenticity and its transparent rating system. In terms of cell degradation the Samsung 25r has been a reliable source of power.

System provided to me by MGM Compro uses Sony US18650VTC6. Rated capacity 3000mAh. 18 stacks of 28. 57 lb with enclosure and BMS.
Projected performance at 25KW draw is 12 minutes.
FWIW
UH

[Dave Nadler]

On Monday, June 11, 2018 at 2:55:08 PM UTC-6, wrote:
> System provided to me by MGM Compro uses Sony US18650VTC6.
> Rated capacity 3000mAh. 18 stacks of 28. 57 lb with enclosure and BMS.
> Projected performance at 25KW draw is 12 minutes.

Thanks Hank - Do they provide any specs (feature list) for BMS?

[[email protected]]

On Monday, June 11, 2018 at 5:37:08 PM UTC-4, Dave Nadler wrote:
> On Monday, June 11, 2018 at 2:55:08 PM UTC-6, wrote:
> > System provided to me by MGM Compro uses Sony US18650VTC6.
> > Rated capacity 3000mAh. 18 stacks of 28. 57 lb with enclosure and BMS.
> > Projected performance at 25KW draw is 12 minutes.
>
> Thanks Hank - Do they provide any specs (feature list) for BMS?

Yep- there is a manual for it. Sent privately.
UH

[Dave Nadler]

On Monday, June 11, 2018 at 5:07:23 PM UTC-6, wrote:
> On Monday, June 11, 2018 at 5:37:08 PM UTC-4, Dave Nadler wrote:
> > Thanks Hank - Do they provide any specs (feature list) for BMS?
>
> Yep- there is a manual for it. Sent privately.
> UH

Thanks Hank!

[Emir Sherbi]

More updates:


https://www.instagram.com/grasshoppersystem/
https://www.facebook.com/charlysierragolf/

[[email protected]]

I suppose you will provide strong protection to the elevator linkage. If anything goes wrong in the pylon mountings, or parts get loose, you really don't want to risk interference with the elevator control.
The static and TE lines would also very much benefit from protection.

I admire all those who dare such complex work

Aldo Cernezzi
www.voloavela.it

[Emir Sherbi]

Aldo,

There will be a very thick floor and sidewalls to reinforce the fuselage structure and that will protect the control rod and cables.
If anything get loose it will stay in the motor bay.

Regards

[Craig Funston[_3_]]

Emir, great to see you moving forward on your project.

I expect you already know this, but at the risk of being redundant, I’ll post anyways. Just thickening the skins in the motor bay area won’t restore the torsional stiffness of the boom. When the hole is cut for the doors the boom goes from a closed tube shape to an open “C” shape. This dramatically reduces the torsional stiffness and strength of that area. You can demonstrate it to yourself with a cardboard tube..

The factories get around this by adding a pair of vertical walls in the engine bay to form two closed “D” shaped tubes, essentially restoring the lost stiffness.

Good luck with your project. I’m looking forward to hearing how it works out.

Best regards,
Craig

[Senna Van den Bosch]

Op vrijdag 26 oktober 2018 04:50:09 UTC+2 schreef Emir Sherbi:
> Aldo,
>
> There will be a very thick floor and sidewalls to reinforce the fuselage structure and that will protect the control rod and cables.
> If anything get loose it will stay in the motor bay.
>
> Regards

This project looks amazing. Do you have any idea of a price that you would like to get for selling such a kit? Also, with any kind of fittings, is there any probability of them getting loose?

[Emir Sherbi]

Craig,

Thanks for the advice. That is the big issue on the project. Is difficult to obtain the same rigidity of a cone like the boom tail once cut. The reinforcement floor and walls will form 3 different enclosed sections with fibers at 45° from the fuselage line.

After the modifications I will test the fuselage with strain gauges to see the new strain distribution and compare them with the original.

[Emir Sherbi]

> This project looks amazing. Do you have any idea of a price that you would like to get for selling such a kit? Also, with any kind of fittings, is there any probability of them getting loose?

The price of the kit will be around 17.000 USD depending on controller and battery capacity choices without installation.
Now that i left my full time job to continue with this project i can travel to make the modifications by myself.

The fastening part of the fittings will be at plain sight. So if you check out them time to time there must be no problems.

[Craig Funston[_3_]]

On Friday, October 26, 2018 at 5:34:13 AM UTC-7, Emir Sherbi wrote:
> Craig,
>
> Thanks for the advice. That is the big issue on the project. Is difficult to obtain the same rigidity of a cone like the boom tail once cut. The reinforcement floor and walls will form 3 different enclosed sections with fibers at 45° from the fuselage line.
>
> After the modifications I will test the fuselage with strain gauges to see the new strain distribution and compare them with the original.

Emir,

Sounds like you've got it covered. It's always interesting to see whether the instrumented prototype matches the modeling.

Best wishes,
Craig

[Emir Sherbi]

Craig,

Yes. But it is very difficult to model composites and worst to model sandwich structures. I am taking some consideration to model the worst case and build up from there. Later I'll test some specimens to see the performance of the layup technique and materials used.

Emir