Electric autogyro

Just on of loud thinking scenarios.

Lithium batteries are cheap to obtain, thanks to Tesla cars being sold and crashed all other the world. So - something like 800-1000 usd per module with 5.6 kw/h capacity and 25 kg of weight (with bms and contractor if i am correct + structure) on module is capable of 30 kw power.

Motors like emrax 188/208 8-9.5 kg with 30-40 kw peak power at 3500 rpm, or 16-20 kw at 2000-2200 rpm.

Controller for this configuration 4-6 kg ?

So in total - 1.5 or 2 modules, + motor/controller will weight 52 kg / 65 kg for 1.5 or 2 packs. And could provide 30-40 minutes of cruise power comparable as rotax 447/503 engines. And with close or same weight as 447/503 with 5 gal of fuel.

+ less weight for prerotator, you have already a lot of batteries.
+ you could build it as tractor in same configuration as JT-11 - propeller/motor - pilot - mast - batteries.

https://i.imgur.com/cBCRoZf.png
 

AirCommandPilot

Just a fledgeling
For the Metric challenged....
the Emax 188 puts out a peak 70kw or 94 hp at 6000 rpm. Or a continuous 30kw or 40hp.
Lets use the max weights here:
*The motor = 6.8 or 9 lbs.
*The controller = 6kg or 8lbs.
*The battery (2 mods) 50kg or 67lbs.
Total power plant with fuel= 63kg or 84lbs.

The Rotax 582 puts out 65hp at 6500rpm and weighs 29kg or 64 lbs.
5 gallons of fuel weighs 14kg or 31lbs.
Total = 43kg or 95 lbs.

I'm not sure what the cruise power of the 582 is, but it looks like the electric motor is starting to look viable for playing with.
 
AirCommandPilot;n1137416 said:
The Rotax 582 puts out 65hp at 6500rpm and weighs 29kg or 64 lbs.
5 gallons of fuel weighs 14kg or 31lbs.
Total = 43kg or 95 lbs.
According to wikipedia: https://en.wikipedia.org/wiki/Rotax_582

Dry weight: 50 kg (110 lb) with electric starter, carburetors, fuel pump, air filters and reduction gear

Plus - if want go for 582 power range - you need emrax 228 at least i think, which is ~12 kg weight. Plus half pack batteries more. Stil +- close mass for 40 minutes of fligth time.

Any info on needed power for cruise/take-off ?
 

Jean Claude

Junior Member
Emax 188? I would very much like to see the datasheet of this electric motor from 94 hp to 6000 rpm weighing 9 lbs. Thank you.
 

C. Beaty

Gold Supporter
Storing electricity: How much does 1 kWh of battery capacity weigh?

A gasoline engine burns ~ 0.6 lb of fuel per kWh. (1 US hp = 0.746 kW)
 
AirCommandPilot;n1137416 said:
For the Metric challenged....
the Emax 188 puts out a peak 70kw or 94 hp at 6000 rpm. Or a continuous 30kw or 40hp.
Lets use the max weights here:
*The motor = 6.8 or 9 lbs.
*The controller = 6kg or 8lbs.
*The battery (2 mods) 50kg or 67lbs.
Total power plant with fuel= 63kg or 84lbs.

The Rotax 582 puts out 65hp at 6500rpm and weighs 29kg or 64 lbs.
5 gallons of fuel weighs 14kg or 31lbs.
Total = 43kg or 95 lbs.

I'm not sure what the cruise power of the 582 is, but it looks like the electric motor is starting to look viable for playing with.
Oops!

1kg = 2.2lbs. Not 1.333lbs.

*The motor = 6.8 or 9 lbs. Should be 15lbs.
*The controller = 6kg or 8lbs. Should be 13lbs.
*The battery (2 mods) 50kg or 67lbs. Should be 110lbs.
Total power plant with fuel= 63kg or 84lbs. Should be 139lbs.
 
Uncle Willie;n1137449 said:
Oops!

1kg = 2.2lbs. Not 1.333lbs.

*The motor = 6.8 or 9 lbs. Should be 15lbs.
*The controller = 6kg or 8lbs. Should be 13lbs.
*The battery (2 mods) 50kg or 67lbs. Should be 110lbs.
Total power plant with fuel= 63kg or 84lbs. Should be 139lbs.
Plus rotax 582 110 lb fuel less.

But again - you are better on not needing starter, starter battery, prerotator contains only motor with ~ 1 kg/kw with gearbox etc..

Must applogise for that emrax, looks not very nice company : http://build-its-inprogress.blogspot.com/2017/05/emrax-motor-teardown.html?m=1

Still. there are many interesting solutions :
 

C. Beaty

Gold Supporter
There’s nothing wrong with electric power for things that move: electric wheel chairs, electric golf carts, electric fork lifts for use in poorly ventilated areas and electric power for some of the largest machines ever made, the walking drag lines used in strip mining. The walking drag lines run from 13 kv extension cords connected to the power grid.

Battery/electric power might some day be useful as auxiliary power for sailplanes. But not for the most inefficient flying machines ever made without a quantum leap in electricity storage technology.
 

Smack

Re-member?
Batteries aren't there yet, but motor/generator with distributed electric power seems feasible. Just need $$$ and time !
Brian
 
C. Beaty;n1137458 said:
Battery/electric power might some day be useful as auxiliary power for sailplanes. But not for the most inefficient flying machines ever made without a quantum leap in electricity storage technology.
I am not comparing it to ordinary long range gyros or best german build sailplanes which climb fast on 10 kw of power.

Think of it as short range, high power reserve gyro.

Just now you may get same mass as 447/503 with fuel and 30-40 minute range. If compare with vw boxer or other car conversion, at lest an hour or more.

Plus - it looks like, what it is possible to reuse more components from hybrid parts. When it is if not free, really cheap.
 

Jean Claude

Junior Member
The necessary technological leap can occur in two years, as well as in two century. An electric gyro can be then built in one month. There is no need to install the fast charging stations today
 

PW_Plack

Active Member
C. Beaty;n1137458 said:
Battery/electric power might some day be useful as auxiliary power for sailplanes. But not for the most inefficient flying machines ever made without a quantum leap in electricity storage technology.
Chuck, how many light, single-seat gyros get flown for more than 40 minutes at a time? For such durations, electric power is already feasible.

The motors and batteries needed to do it are coming down in cost. My only concern is that lithium-based storage batteries lose capacity quickly if they're cycled between 100% and 0% charge, or if they're floated at max charge for long periods. This application could encourage both. If the norm becomes leaving it on the charger for weeks, then running it down to 0% in 40 minutes, the per-flight-hour cost of battery replacement will be an unwelcome surprise.
 

C. Beaty

Gold Supporter
[h=3]A light weight gyro needs energy storage of something like 30 kWh for 40 minutes of flight time if more than one takeoff is made. That requires 18 lb (3 gal @ 0.6 lb/kWh) of gasoline or 330 lb (11lb/kWh) of lithium battery. But the electric gyro won’t make the light weight category and will need even more battery.
By way of comparison, a 4,000 lb automobile needs ~ 15 hp (11 kW) for steady cruise at 60 mph.
[/h]
 
Sorry, but are you sure on that 30kwh at 40 minutes flying time ? It is like 45kw steady power.

Or about 136 kg of thrust

But where are plenty of rotax 447 gyros in pusher configuration. Not a rocket, but it flies and climbs ok with less loaded rotor. With 3-3.5 gal of fuel for one hour.

I think that best comparision to electric, is not far103 class rotax 447 poewered gyrobee like autogyro, but one seater powerd by vw boxer engine.
 
Last edited:

C. Beaty

Gold Supporter
I slightly understated battery size by not allowing for the fact that the efficiency of electric motor and controller is not 100%. Although their efficiency is good, perhaps as high as 90% for each, the overall efficiency is the product of controller and motor efficiencies; say 80% overall. Thus, the battery weight should have been 330/0.8 = 413 lb.

When it comes to electric propulsion, wheels on the ground is one thing; a rotor thrashing the air at nearly the speed of sound is something else.
 

C. Beaty

Gold Supporter
We’ll just have to wait for that technological leap in battery energy density, which as JC says, could be 2 years or 2 centuries. Maybe never.
 
Top