New electric project

Homebuilt Aircraft & Kit Plane Forum

Help Support Homebuilt Aircraft & Kit Plane Forum:

emotodude

Well-Known Member
Joined
Nov 5, 2020
Messages
49
I think you follow most logical way.
If is request for demo aircraft, than your choice - Sonex - makes sense.
You modified Xenos to eXenos = you can use a lot of experience you already learned ;)
Maybe you can ask producer for "small" modification and get "a little bit longer wings" :cool:
Of course not Xenos wings.... but even for example 30 ft span instead of 22 ft span will help.
Yah looking at the Allenflight extended tips on the Sonex.
 

Tom DM

Well-Known Member
Joined
Mar 31, 2022
Messages
104
Location
EBGB Grimbergen airfield (N of Brussels, Belgium)
"emotodude, post: 660266, member: 104469"]
You say "stay rooted in old-fashion mathematics / technical data" but provide no substantiation for your claim of 30kW for level cruise.
"

=> See other thread. A T211 holds straight and level flight @2200-2250 RPM on O-200, 1 POB , flying weight 450kg, speed around 70 kts. Powersetting / fuel flow indicate around 50Hp / 30-35 kW.

A Sonex may be a tiny bit lighter, power requirements will be quite similar and certainly not 30-40% less... but that you will find out. You might ask the minimum powersetting a Sonex-jockey can ride. I give my *real flight* data free of charge, you may collect yours as you see fit.

And with all respect: I don't have any problem with needing 30kW continuously in flght, but the pilot of your stated plane does.


"
I provided substantiation for my claim of 20kW. The Sonex claims L/D 11:1, the Xenos 22:1. 1/2 the L/D requires double the power, all else being equal. The Sonex will also be about 100 lbs lighter than the Xenos. Following this logic, cruise power should be ~20kW.

Understood that this is not a "practical" aircraft. It will just be for fun demonstrations and short zippy commutes.
"

=> Won't even serve the latter purposes . The plane enters illegal flight from the moment of take-off, you might get away with that if specific permissions are asked.

My experiance with civil air autoroties (in Belgium) is such that all their body but mouth screams NO when the word "experimental" comes up. I guess suggesting flying into legal reserve equals returning the licence. I hope you fare better.

As to the mission of short zippy commutes. that will be limited to going from hangar 1 to hangar 2 on the same airfield unless your plane has VTOL-capabilities.

"
I should add that the purpose of this post was primarily in looking for any other or "more" suitable airframes...
"

=> You look imho for an airframe -fault-solution when the airframe is not the problem, any smaller two-seater will do what you demanded in OP.

The batteries are your sole problem and there you are in good company as up till the new all singing all dancing feather-light battery, annonced 2 years back for yesteryear, arrives and lives up to the requirements.
 
Last edited:

John.Roo

Well-Known Member
Joined
Oct 8, 2013
Messages
1,548
Location
Letohrad / Czech Republic
This project remindes me project EPOS.
Evektor Eurostar with electric propulsion.
1652241203772.png
They used 75 kW motor and 4 battery packs.
MTOM has been 600 kg.
With two pilots they could use only 2 battery packs.
In case of solo flight they used all 4 battery packs so endurance has been arround 1 hour.
Battery pack weight was 53 kg and each pack contained 45 cells KOKAM SLPB100216216H.
I remember that to keep horizontal flight they needed arround 24-25 kW of power (question is at what speed - it was definitelly not 170 kmph).
However I would not call it "cruise power" - I would call it "power to stay in horizontal flight" ;)
 

raumzeit

Active Member
Joined
Mar 23, 2021
Messages
40
Kitplanes June 2020 edition had an article re: converting an homebuilt Strojnik S-2A Sailplane to electric utilizing wrecked Zero components......
Was self-launching, but don't know kW consuptions at TO and Cruise.
Looks an easy build!
If you want that particular e-glider it is for sale ->


It was for sale on wingsandwheels last summer for about double that - but nobody knew about a dead battery yet.
 

Tom DM

Well-Known Member
Joined
Mar 31, 2022
Messages
104
Location
EBGB Grimbergen airfield (N of Brussels, Belgium)
"I should add that the purpose of this post was primarily in looking for any other or "more" suitable airframes... "

" I'll remember your skepticism as I'm boring holes in the sky."

I get the impression that the reason for your OP was not a quest for knowledge, advice or finding another viewpoint.
Its aim seems to be generation interest, publicity, the infomercial kind of way, accompanied by some ego-polishing.

You know already everything in a kind of sales-persons-way. Nothing wrong about that: sales/ marketing-folks need to live too but it would be nicer -and ultimately more effective- if the real intentions were stated upfront.

Enjoy the boring business.
 

emotodude

Well-Known Member
Joined
Nov 5, 2020
Messages
49
I get the impression that the reason for your OP was not a quest for knowledge, advice or finding another viewpoint.
Its aim seems to be generation interest, publicity, the infomercial kind of way, accompanied by some ego-polishing.

You know already everything in a kind of sales-persons-way. Nothing wrong about that: sales/ marketing-folks need to live too but it would be nicer -and ultimately more effective- if the real intentions were stated upfront.

Enjoy the boring business.
Tom, the intent of my OP was exactly what was stated in it. To inform folks of my new project and see if there were any airframe options I should consider. No hidden agenda. Not trying to make money, sell a product, profit or benefit in any way. The only intention is to build something awesome and show the world what can be done. Your continuous negativity, ignorance, misinformation, and vague implications of some nefarious intent are getting old, I will no longer waste my time responding to you.
 

tspear

Well-Known Member
Joined
Feb 12, 2014
Messages
1,157
Location
Outside Boston
@emotodude

I know very little about them, but I have read that Gyrocopters are very light with high L/D ratios. Can effectively glide back to land at very slow speeds if you run put of power...
Might be a completely different direction to consider for aircraft #4. :D

Good luck,

Tim
 

tspear

Well-Known Member
Joined
Feb 12, 2014
Messages
1,157
Location
Outside Boston
@Tom DM

Picking the Thorp as an example is a very poor choice. Every ICE powered plane when compared to an electric plane shows substantial power/energy used to overcome cooling drag. A side by side comparison of power of the Pipistrel Elektro vs the Rotax version show the ICE version consumes almost 50% more power to perform the exact same mission (but has so much more energy it still is faster and goes farther).

The OP also provided actual numbers from his currently flying concept ePlanes.

Tim
 

John.Roo

Well-Known Member
Joined
Oct 8, 2013
Messages
1,548
Location
Letohrad / Czech Republic
@emotodude

I know very little about them, but I have read that Gyrocopters are very light with high L/D ratios. Can effectively glide back to land at very slow speeds if you run put of power...
Might be a completely different direction to consider for aircraft #4. :D

Good luck,

Tim
"Gyrocopters are very light with high L/D ratios."
Sorry, that is mistake.
L/D of gyroplane is very low.
Gyroplane construction is simple so you can achieve low weight, however gyroplanes are also machines with high aerodynamic drag so they need a lot of power to fly.
 

Tiger Tim

Well-Known Member
Joined
Apr 26, 2013
Messages
4,450
Location
Thunder Bay
Is minimum power for level flight the metric to go by when picking an airframe for electric conversion?
 

tspear

Well-Known Member
Joined
Feb 12, 2014
Messages
1,157
Location
Outside Boston
"Gyrocopters are very light with high L/D ratios."
Sorry, that is mistake.
L/D of gyroplane is very low.
Gyroplane construction is simple so you can achieve low weight, however gyroplanes are also machines with high aerodynamic drag so they need a lot of power to fly.
Hmmm... I was thinking of the blade (airfoil). Not the total vehicle. I know very little about them, but they always appeared to have only a small engine compared to part 103.

Tim
 
Top