Design a Electric Aircraft.

HomeBuiltAirplanes.com

Help Support HomeBuiltAirplanes.com:

blane.c

Well-Known Member
HBA Supporter
Joined
Jun 27, 2015
Messages
3,848
Location
capital district NY
A place to start. To see if there is interest.

(1) Determine and understand the rules it will be flown under.
(a) glider (b) airplane (c) other (d) single place (e) two place (f) more than two place (g) single motor
(h) multi motor (I) fixed pitch propeller (j) in flight adjustable propeller (k) folding or feathering propeller

(a1) Do you need a license of any kind to fly a EAB glider solo?

(2) Propeller, motor, controller, batteries and other necessity's.

(3) Everything else (for now)
 

dog

Well-Known Member
Joined
Dec 29, 2019
Messages
254
A place to start. To see if there is interest.

(1) Determine and understand the rules it will be flown under.
(a) glider (b) airplane (c) other (d) single place (e) two place (f) more than two place (g) single motor
(h) multi motor (I) fixed pitch propeller (j) in flight adjustable propeller (k) folding or feathering propeller

(a1) Do you need a license of any kind to fly a EAB glider solo?

(2) Propeller, motor, controller, batteries and other necessity's.

(3) Everything else (for now)
Two place,motor glider,single engine,inflight adjustable/feathering.
In Canada, motor gliders are exempt from some of the requirements vs/vs licencing.
The electrical bits are becoming common place.
Everything else is marketing.
 

blane.c

Well-Known Member
HBA Supporter
Joined
Jun 27, 2015
Messages
3,848
Location
capital district NY
Two place,motor glider,single engine,inflight adjustable/feathering.
In Canada, motor gliders are exempt from some of the requirements vs/vs licencing.
The electrical bits are becoming common place.
Everything else is marketing.
How are they exempt exactly?

Could you explain common place?

Why did you change gimmy to marketing and either way what does that mean?

Why would you personally prefer feathering to folding?
 

dog

Well-Known Member
Joined
Dec 29, 2019
Messages
254
I believe there is no medical required for motor gliders in Canada
Commonplace in this instance would mean 200 vendors all over the world ready to risk my life on there motors and controlers
I changed gimmy because I realized I would have explain it,ha.And have been thinking about marketing and what it would take to interest
the current generations.
The feathering could be an option, and with the advent of chips with sensors running "algorythems"
An all electric motor prop combo might have performance advantages.
Think tesla"insane"mode.
Or back to marketing"eco" mode,endurance, etc.
 

blane.c

Well-Known Member
HBA Supporter
Joined
Jun 27, 2015
Messages
3,848
Location
capital district NY
There is no medical requirement for gliders USA.
For EAB glider solo "I read the regs as no license required" but would like clarification.
For EAB airplane solo ?
For passengers you need either a glider or an airplane license as appropriate.
Clarification on the above rules makes it easier to decide what you want to build or at least how you want to register it.

Commonplace … makes me want a glider with some "legs".
Selling … we all know the adage.
Feathering may be quicker, "I don't know" than folding regards repowering, if you wanted or needed to power back up but folding is likely less drag. Using the propeller to regenerate could cut down on the weight of spoilers (they could be smaller or none). Having the computer do it all for you is likely a scenario others will want but I do not. But having the computer screen showing some likely parameters for airspeed and watt usage in regards propeller adjustment and "time" could be helpful.

The thing about a glider is it is the engine (in its own way) and (we hope) needs no backup. Therefore it only needs a motor for self launch and sustain.
 

dog

Well-Known Member
Joined
Dec 29, 2019
Messages
254
T

Commonplace … makes me want a glider with some "legs".
Feathering may be quicker, "I don't know" than folding regards repowering, if you wanted or needed to power back up but folding is likely less drag. Using the propeller to regenerate could cut down on the weight of spoilers Having the computer do it all for you is likely a scenario others will want but I do not. But having the computer screen showing some likely parameters for airspeed and watt usage in regards propeller adjustment and "time" could be helpful.


The only option for an electric powered aircraft is
to have a computer contol how the power is pulled from the batterys,unless you want to do it free hand with jumper cables.
So there is an "algorythm" or twelve one of which could be a short burst that could very likely generate a rate of climb unpresidented in a propeller driven craft of the size we are talking about,not gona take you into the flight levels,but if it can hold 4000 ft/min for 1min, who isnt going to hit the happy button once.Let the computer mind the heat.
 

blane.c

Well-Known Member
HBA Supporter
Joined
Jun 27, 2015
Messages
3,848
Location
capital district NY
Yes the computer is in control regards the batteries and the motor, I thought you meant the computer would adjust the propeller too. Which it could but I am not sure I want it making all the decisions.
 

lr27

Well-Known Member
Joined
Nov 3, 2007
Messages
3,730
1. Part 103 self launching sailplane. More capacity for cruise would be nice, but not mandatory. A speed limiting device might be required for such a clean aircraft, but should not constrain climb performance.
2. Multiple hobby motors and folding props. You can get them at least as large as 23 inches. A nice feature of these is that if you throw a blade it probably won't be the end of the universe. I would take a harder look at the safety and reliability of the batteries and speed controls. Maybe use LiFe instead,of lipos. Motors might be mounted a la Pathfinder UAV, with batteries near the motors in the wing. These could be arranged so that wing's balance point was at 25% MAC.
3. Capacity for a relatively large pilot. Especially width at shoulders and headroom.

It would be nice to have performance close to that of the Carbon Dragon.

This project would be just for me, though maybe not in this life unless I demonstrate much more productivity with models first.
 

Hot Wings

Well-Known Member
HBA Supporter
Log Member
Joined
Nov 14, 2009
Messages
6,766
Location
Rocky Mountains
Feathering may be quicker, "I don't know" than folding regards repowering, if you wanted or needed to power back up but folding is likely less drag.
Someone on another thread came up with an option other than folding or feathering when using an electric motor, that I thought was quite insightful:

Just turn the prop at the speed where it provides zero thrust or zero drag. The delta between the 2 should be small. Given that the prop is in theory doing no work, other than some parasite drag, the power required from the batteries should be very small.
 

lr27

Well-Known Member
Joined
Nov 3, 2007
Messages
3,730
The prop might not be doing any USEFUL work, but it would still have some drag that the motor would have to compensate,for.

Also, if one were to catch thermals or fly on bumpy days, an automatic gadget to maintain that zero thrust at different airspeeds would greatly reduce pilot workload.

Personally, I think aircraft are usually too noisy even when nothing is spinning.
 

blane.c

Well-Known Member
HBA Supporter
Joined
Jun 27, 2015
Messages
3,848
Location
capital district NY
So any thoughts on what size motor to use and what controller to use with it, and what voltage would you prefer and how many batteries? What is it all g
1. Part 103 self launching sailplane. More capacity for cruise would be nice, but not mandatory. A speed limiting device might be required for such a clean aircraft, but should not constrain climb performance.
2. Multiple hobby motors and folding props. You can get them at least as large as 23 inches. A nice feature of these is that if you throw a blade it probably won't be the end of the universe. I would take a harder look at the safety and reliability of the batteries and speed controls. Maybe use LiFe instead,of lipos. Motors might be mounted a la Pathfinder UAV, with batteries near the motors in the wing. These could be arranged so that wing's balance point was at 25% MAC.
3. Capacity for a relatively large pilot. Especially width at shoulders and headroom.

It would be nice to have performance close to that of the Carbon Dragon.

This project would be just for me, though maybe not in this life unless I demonstrate much more productivity with models first.
From EMG-6 website

EMG-6.png

What is the advantage of part 103 compared to EAB glider when considering electric? With an EAB glider you do not have the weight restriction of part 103. There is registering the aircraft as a glider and the EAB inspection to get a experimental license but that seems far more reasonable to me than trying to keep the weight under 254lbs and carry any reasonable amount of batteries.

edit P.S. if glider pilot rated you would need a self launch authorization sign off from a qualified instructor.
 

lr27

Well-Known Member
Joined
Nov 3, 2007
Messages
3,730
Part 103 means a lot less expense and a lot less contact with the FAA. It might mean a lot more design effort before building, but isn't that the fun part? Obviously, some training would still be required, but I'm sure it would be less than for a conventional aircraft. How many motors probably depends on how big an inexpensive folding prop I could find. If 20 inches, maybe 8 or 10. It's been a long time, but I think I figured out once that it would be possible to get to something like 2,000 feet or more with a reasonable amount of weight for the whole system. Making optimized motor choices well in advance might be ok for feasibility, but by the time the project was ready, there woukd probably be better options.
 

Hot Wings

Well-Known Member
HBA Supporter
Log Member
Joined
Nov 14, 2009
Messages
6,766
Location
Rocky Mountains
What is the advantage of part 103 compared to EAB glider when considering electric?
2 come to my mind:

Part 103 = no registration = no paper trail for the tax man to follow.

DARs seem to be getting harder and harder to find, especially ones that aren't going to make a builder jump through unreasonable hoops just because of their own personal requirements or poor understanding of the regulations and reasons for the whole Experimental thing. Ask Pops about his rivets............
 

Elmog

Well-Known Member
Joined
Apr 9, 2010
Messages
99
Location
Anaheim
To build an airplane powered by a 35 hp motor that would have a 1 hour range with 1/2 hr reserve would require a 52.5 kW battery that would weigh between 400-600 kg (880#-1322#) depending on the battery's makeup.

EX:
746 watts = 1 hp for 1 hour. (Rnd off to 1000 watts for efficiency losses)
35 hp x 1.5 hours = 52.5 hp used, or 52.5 KW of energy.

Or-

A Cessna 150 with a 100hp motor using 75% power for 3hrs plus .5 hr reserve (not including T/O or climb power setting) would need a 260k kW battery pack. Want to guess what that battery would weigh?

We have a long way to go before we build airplanes with reasonable speed/range within a price range that the average plane buyer/builder can afford. However, dreaming is always great as is it is the impetus that will lead to the next major breakthrough.
 

blane.c

Well-Known Member
HBA Supporter
Joined
Jun 27, 2015
Messages
3,848
Location
capital district NY
Well 35hp sounds like a reasonable number to start with for electric not knowing any better. But how do you compare it to an ic engine? The motor is direct drive but what rpm is it getting 35hp? Are we using a shorter faster spinning propeller than a traditional ic engine?

400kg of battery doesn't sound that bad. I mean it sounds better than 880lbs.

Others are doing it somehow. It must not be impossible.

The controller is the magic dust eh? But the magic boxes are not all black they come in many colors.
 

lr27

Well-Known Member
Joined
Nov 3, 2007
Messages
3,730
At the moment, an electric plane needs to be far more efficient than one powered by an IC engine and relatively cheap gas. Fortunately, in some applications that's possible. The days when you can yank the engine out of your draggy Cessna and put in a useful electric setup are probably far off.
 

blane.c

Well-Known Member
HBA Supporter
Joined
Jun 27, 2015
Messages
3,848
Location
capital district NY
I never thought of a swap as a good idea. I see that electric is working in motor gliders. I am not sure how it could play out with an airplane. I was thinking more of a 2 place HP-24 for electric touring. Maybe a hybrid for airplane, were the ic engine is used for cruise and the electric is for back up and extra power during take off, initial climb and for emergency but otherwise stowed somehow. So maybe the electric needs 20 minutes of power, less than 5 minutes initially and 15 minutes in reserve. It is a lot of weight though basically it would carry itself into the air and hang out wasting hp and gas in the hopes you might need it someday. But it may be more efficient than running two ic engines all the time but you'd have to run the numbers.
 

dog

Well-Known Member
Joined
Dec 29, 2019
Messages
254
I never thought of a swap as a good idea. I see that electric is working in motor gliders. I am not sure how it could play out with an airplane. I was thinking more of a 2 place HP-24 for electric touring. Maybe a hybrid for airplane, were the ic engine is used for cruise and the electric is for back up and extra power during take off, initial climb and for emergency but otherwise stowed somehow. So maybe the electric needs 20 minutes of power, less than 5 minutes initially and 15 minutes in reserve. It is a lot of weight though basically it would carry itself into the air and hang out wasting hp and gas in the hopes you might need it someday. But it may be more efficient than running two ic engines all the time but you'd have to run the numbers.

The other idea is to have an ICE burried somewere
convienient in the airframe that is only conected to
a generater,the "airius",or put it up front and put the electric motor/generator in a flywheel and clutch to the ICE.
One advantage to a ICE conected directly to a generator is that it can be optomised to run at one
RPM only,which saves a bit of weight and helps with designing an efficient exhaust(quiet),simpler
fuel injection,ignition,everything has only two settings,start and run.
Complex though,there is a real effort at this up somewhere in northern europe with a small flying boat,they got it to fly on strait electric and then promptly broke it.
 
Last edited:
Group Builder
Top