All-Electric MakerPlane

[jeff54il]

Great idea of John to post a new topic All-Electric MakerPlane

Some time has passed since the original idea of MakerPlane was presented. During that time electric propulsion technology has come a long way and is becoming (or already has become) available off-the-shelf at very reasonable prices. Combine that with the liberal "Experimental" and LSA rules and it's only a question of (a short) time before we'll be in the era of homebuilt all-electric aircraft. It is no longer a question of developing the technology, but choosing from already available technology.

personally, I feel that the all-electric MakerPlane should not be a derivative of existing aircraft design philosophy, but an out-of-the-box design from scratch - literally from the ground up.

The technology now exists, but here are some points that need addressing (not necessarily in order of importance):
1. Single engine or twin?
2. NiMh battery or Li-ion?
3. Fixed pitch or variable pitch propeller?
4. Flight training mission or hundred dollar hamburger?
5. Mechanical or electronic control linkages?

I'm sure other issues will come up as we move along, but the above are enough to keep us busy for a while.

[John Nicol]

Discussion moved to a new subject under All Electric MakerPlane.

[jeff54il]

After my own heart...

[magnus.bieneck]

Hi Jeff,

I really like the idea of the electric MakerPlane! Mount solar panels on your hangar roof, and you are literally paying nothing for your fuel

One point I would like to challenge: Why should we use off-the-shelf battery packs? We could also think about creating custom batteries which are optimised for the MakerPlane in their capacity, size, shape etc. It would also safe us some money and thus reduce the TCO. There are some quite nice open source BMS (Battery Management Systems) [1-2], that would be easy to integrate with our EFIS.

Best,
Magnus

[1] https://github.com/Green-bms/SmartBMS
[2] https://github.com/foxBMS/foxbms-2

[jeff54il]

Hi Magnus,

Thanks for your feedback - very encouraging

Commercial Off-the-shelf (COTS) battery packs: I absolutely agree with you on the issue of COTS battery packs - we could definitely develop an optimum configuration using one of the beautiful BMS chips available today. This is a project in its own right and would of course use a COTS BMS chip and COTS batteries .
By far the biggest problem with all-electric aviation is the low energy density battery itself and the safety issues associated with it, not to mention the prolonged charging times and associated infrastructure required.

I don't want to sound like the party pooper, but we can also develop at least 3 other similar sub-projects, each one being a project in its own right:
1. The MakerPlane Brushless Electric Motor.
2. The MakerPlane ESC (Electronic Speed Controller).
3. The MakerPlane Propeller that is optimised for the above.
I also have my own personal project - Triply redundant servo actuators required for the MakePlane FBW (Fly-By-Wire). I've done some substantial work on the mechanical side, but I have much too little experience with the electronics and embedded software. Maybe you can help?

Best regards,

[magnus.bieneck]

Hi Jeff,

By far the biggest problem with all-electric aviation is the low energy density battery itself and the safety issues associated with it, not to mention the prolonged charging times and associated infrastructure required.

Agree. The Pipistrel Velis Electro uses both a liquid-cooled electric motor and liquid-cooled battery packs. So we might also think about adding a liquid cooling system.

I don't want to sound like the party pooper, but we can also develop at least 3 other similar sub-projects, each one being a project in its own right:
1. The MakerPlane Brushless Electric Motor.
2. The MakerPlane ESC (Electronic Speed Controller).
3. The MakerPlane Propeller that is optimised for the above.

Oh yes, that would be great! Would even save more money/reduce TCO, and we do not need to limit ourself by what the market provides. However, it would take even more time to develop

I also have my own personal project - Triply redundant servo actuators required for the MakePlane FBW (Fly-By-Wire). I've done some substantial work on the mechanical side, but I have much too little experience with the electronics and embedded software. Maybe you can help?

Regarding the software, I can have a look and try to provide basic help, though embedded is not really an area where I have a lot of experience... Would you like to send me a PM with more details?

Best,
Magnus

[BruceMe]

I'm picking up a project I dropped to convert a single-seat exp Silohette motorglider to an all-electric. I have all the components, the battery is where I'm stuck.

[MonicaHSE]

No John, I don't have more time to solve problems, just more time to make new problems
So, I've come up with a new crackpot idea based on my last 10 years or so experience in drone design - may fit in with the MakerPlane concept.
How about an all-electric MakerPlane? Before you discard this crazy post let's look at some of the issues, advantages and challenges:
Advantages: Quiet, Low vibration, Reliable (motor has only one moving part), Very light weight (except for the battery).
Challenges: Battery weight, Battery weight, Battery weight, ...
Notice I've left out availability of motors and overall cost - this is because I don't see this as an issue.
Here is a motor+ESC(Electronic Speed Controller)+62" propeller that will give you 70Kg of cruise thrust. The combo (motor+ESC+prop) comes from the RC hobby market but is designed for manned aircraft, costs US$2000 and weighs 8 Kg. And the motors are only 6" in diameter!! And the motors+ESC is designed to work at 100V (Toyota Prius battery pack voltage).
https://store-en.tmotor.com/goods.php?id=891.
Make a 400 Kg two-seat airframe with two (or 3) of these combos and you'll end up with an extremely reliable MakerPlane Twin
. With 140Kg of cruise thrust and a 10:1 glide ratio that will leave you with hundreds of Kg for batteries.

So, that leaves us with (IMHO) the only real issue - battery weight. But the automotive industry is pushing extremely hard towards all electric cars and it (the automotive industry) has the battery weight and size problem in common with us. Big brother is not just watching - he's pushing much harder than we are. Today an hour-long cruise in our MakerPlane Twin will require 3 Toyota Prius battery packs (weight 80 Kg each).

Quick cost and weight estimates:
Payload 2 adults (200 Kg) + 50Kg baggage
Airframe 500Kg (includes 2 motors & more structure to carry batteries)
2 hour cruise - 6 Prius battery packs = 480Kg
All up takeoff weight 1230Kg (or if you can live with 1 hour cruise AUW 990Kg)
Motor combo cost 2x$2000 = $4000
Battery cost 6x$2000 = $12000

And best of all - I'll be able to try out my life long dream - Fly-by-wire controls

Hi, Maybe this link will be helpful to you

[jeff54il]

Hi MonicaHSE,
Welcome to the MakerPlane Forum.
Your link points to a rather large company that sells about 300,000 products.
Which of them did you have in mind when supplying us with the link?
Best regards,
Jeffrey