Hi Benry,

There are plenty of possible configurations to meet different needs as a mater of fact.

A pure electric gyro could be Ok for short pattern training as Cameron says .

but flying purely electric is something that works better on small motor/Gliders then on draggy Aircrafts like Gyroplanes
let's say that it takes 35 kw to level fly with our mono, flying one hour would require a 35 kw/h battery mate.

lithium ion batteries provide 180 w/h per kilos ... then it takes a 35.000/180 = 194 kilos battery to fly an hour ..

So mate .... forget about it , add 15 kilos for the electric motor and the controller and you will have an engine/"tank" assembly of 209 kilos ...instead of 85 kilos of Rotax+fuel full fuel tanks ..

it is just impossible mate... it is Ok for a motor glider but not for a gyro..

Sorry for that.

On the other hand let's imagine an hybrid gas/electric engine capable of an output of 35 kw in electric only .. just in order to maintain the gyro in level flight .

the gyro would need 583w/h of battery capacity per minute to fly level

for 5 minutes the gyro would need a 2920W/h battery capacity

a 2920 w/h battery would weight 2920/180 = 16,2 kilos

Imagine then that you are flying level at 3000 feet and that the gas engine stopped .. you would not need the full electric motor thrust to glide to a nice landing point, you would just add a bit of thrust in order to double the gliding ratio, and to properly make a powered landing to shorter your landing distance.

it is just an example, the rate of hybridation can be adjusted to our goals

we could imagine using a 80 hp (60 kw) rotax 4 stokes (ligth engine) and add a 32 kilos battery

the battery could provide the extra 32kw to take off during 2 minutes, and then lets say just 15 extra kw to climb for 10

it would eat 3500 w/h from the battery 6000 W/h battery and the battery could be recharged in 10 minutes using the electric motor regen capability

the back with 6000kw/h we could easily fly level a good 10 minutes, and much longer descending to a landing spot using only a fraction of thrust in order to extend the gliding ration ending up doing a powered spot landing.

when the batteries will get a better energy density those numbers could be more then double ...

then the rate of hybritation could increase up to the point that a fule engine will become use less

I am going to finish my pre-rotator to gain experience in the field , but I don't think it would be so complicated to replicate the hybrid system shown by Cameron

Sounds plausible and doable on a kit build scale.
Now about my maintenance?

The Rotax maintenance manual is totally impossible to follow ...

Removing the cylinder head to check the diameter of the piston and roundness of the cylinders every 50 hours is totally stupid and also dangerous for the engine...

home builders don't have any obligation to follow the rotax requirement in france .. i believe me I don't

of course I change the spark plugs every 30 hours, of course I monitor the gear box oil every 50 hours etc etc .. I do all what rotax recommends as long as I don't have to remove any parts of the engine .. and especially not the cylinder head ....

my engine tell me all ... I don't have any electric started ... when it starts after 2 or 3 strokes it means that it is in good shape

if there are no leaks,

if the liquid levels are ok

if there water temperature, EGT's are ok ... no problem

what I do on the other hand every 100 hours is that I remove the exhausts, and the carbs, I install caps I have machines in order to seal the engine and then I use a mitiva pump with a manometer and check if the engine has not air leaks.

also I replace the Carburator rubber tubes (I don't know how you call it) to make sure that there are no air leaks

air leaks are the enemy of the 2 strokes engines, if there is an air leak, not enough fuel will get in the motor ... hence the mix will become lean and the engine will size ...

the egt's tell you all about the mix .. it the mix get lean the egt's will go up .. then it will be time to land as soos as possible coz anyway the engine will make you land ...

you can do most of those check and maintenance yourself..

and anyway you don't have the choice .

I did not want to do it myself ... but I ended learning this and doing this myself ...

the only hazard for the newbie is to over tight the spark plugs ... always use the dedicated tool to do it ( then same as for motorbikes) and not a tool with a long handle ...

So mate .... forget about it , add 15 kilos for the electric motor and the controller and you will have an engine/"tank" assembly of 209 kilos ...instead of 85 kilos of Rotax+fuel full fuel tanks ..

Hi mate, Batteries have come on a bit. However you are right to be cautious. For one we need to be careful when we are being clear about speculation vs can I buy it now or can I buy it in the near future. the New Tesla 4630 batteries are 275-295w/kg. Can I get these yet, probably no but they actually exist and they are building factories to put them in cars as we speak. So I have high confidence about what can be achieved with them. Which is not much for the reasons you have given. As a ground trainer yes, doing maybe 3 or even 4 short circuits (some airstrip want you fly in the same pattern as fixed wings). I think given the speed differences this is a bad idea. We flew tighter, lower circuits (partly because we could stay out of the way of the fixed wings and also to minimise the time in a speed approach where the fixed wing is coming in very shallow, but also because in our country there were 2 categories of licence one that required you to land back at the same airport you took off from but limited your chance of conflict with other traffic by having a maximum altitude of 500ft and a minimum of 300ft agl. So a circuit like this (and this is usually the first licence a gyro pilot unless already licensed in say fixed wing and ultralights would start with). Latter most would then do the BAK and move to 500ft min 5000max like other ultralights. But if you are at only 500ft doing a super wide circuit is not really sensible, in a light single seater you may be only flying at 30-35mph best LD and thats a lot of time for a fixed wing doing 100mph+ to run up your arse. So when I talk about circuits understand I'm talking about shorter and lower circuits, climbing only to 500ft max and much closer to the airstrip hence a much quicker circuit and thus many more on a small battery pack.

However I don't imagine even with the 4630 batteries being able to do more than 2 or 3 at the outside before needing to stop and recharge. The new solid state batteries comming on line (that is the ones panasonic are right now building factories to build) are 450w/kg ish again they will not be available for a couple of years these will give us more.

But yes Hybrid is a good idea. Considering the weight of the motor if you are using it as top pully as well is a great idea. My thinking is even if only using to do a max climb out so an additional 44kw for 1 minute it would massively increase rate of climb from the 44kw petrol engine. And this won't need a big battery as you say. Again for a training machine (two seater) you might sacrifice half your fuel capacity for even more batteries (if you are going to be doing multiple circuits). Remembering you don't need 2.5 hours of fuel in a training aircraft. 1 hour endurance + some reserve would be enough.

The other thing to remember too is cost. The motor I showed is a cheap 4 stroke areo conversion but basically a throw away engine probably more reliable than a 583 but possibly not by much. Cost of overhaul in this country is massive for a 583 and now required for two seat machines like areochutes and so forth. So the question is how much do you need to spend per hp. So a rotax 914 (similar hp) is bloody expensive and this hybrid motor with a small battery pack would still come in at 1/2 cost or less. As they tend to not keep turbo active anyway other than initial climb out I think for two seat training such a motor would be cheaper and as battery chemistry improves that battery pack will give more and more sharp climbs to say 500ft or 1000ft.

I think we are probably min 8 years before we could have a genuine electric paddock basher (we'd need 800w/kg) gyro but that's speculative based on the current batteries I've read research papers on but like Nuclear fusion (they just exceeded energy put in by 0.5 extra - but as the laser require something like 10 x that power to generate the laser beam we are still a lot of engineering solutions away from viable fusion power) some of these may not be possible. At last the electric transport and storage revolution has now directed billions of dollars towards R&D.

Fortunately for me I'm a very slow builder. Needless to say after I finish this powered gyro - after I finish the gyroglider - then the next building project will be make a super light airframe all chrome molly to be able to fit an electric motor to. But if battery development stalls out then I'll have a super light airframe to add some other motor to.

Have a great Christmas.

Hi mate I agree with what you say, I don't know if we will see all of this, but if I look back instead of looking in the future I can say that when I got my first electric Mike (the Vectrix) I could only go from Cannes city to Nice city 35 km away (by motorway) at 100 km/h and could not get back hone without charging
today I can easily go to work and get back home with 35% energy remaining in my BMW c evolution bike , still at 100km/h on the motorway
let's say I have triple the range in 14 years thanks to the lithium revolution (my fist bike had a NIMH battery)
but lithium iron batteries have have been invented in 1985 .... nearly 40 years ago ...
how long are we gonna wait for next revolution ?
nevertheless with 300w/kg it would already be possible to make a good hybridation ..
let's do the maths again ... if we consider that we need 35.000 w of power to fly level and that wee need a 10 minutes of thrust if the fuel engine stops .. we would need a (35/60)x10 = 6 kw/h battery for this , and this battery would weight 6000/300 = 20 kilos battery
those 10 minutes in a situation where we would face a fuel engine failure at 3000 ft would transform in a longer thrust time because we would use less energy to descend then what we need to level fly ..
all of this would be realistic and would low down the engine failure stress and enhance safety.

Yes I think for the time being we are going to be looking at solutions like this. The real question is how little power can we sustain flight on. And glide ratio is a good metric of this. Apparently Scientific American had an article about a guy who created a formula to work out minimum power use for aircraft based on a couple of variables, such as mass and glide ratio. In theory this should be true of all aircraft. When trying to figure out the numbers the best I can do (currently) is how long at full power. We know that the Nano gyro flies on 38hp. What does it use at best LD though. This is crucial for a pure EV gyro. The helicopter above was hovering for 20 minutes. I have no idea how many batteries they use and if that's 20 minutes to utterly flat (not good for Lithium batteries). but I suspect glide ratio of choppers is even worse than gyros. Trouble is there is a lot of setting up for flying such as pitching your prop for best speed, but best speed that still suits the preferred rev range of say a Rotax. Electric motors have pretty much constant torque.

In terms of development of batteries if you look at the cost and energy/kg curves of batteries since the laptops and phones and now electric cars its been a massive increase in energy density. Lithium batteries were good for say a holiday as they lasted longer but as they were expensive I rarely brought them they really had limited applications until PC laptops then phones demanded ever higher energy densities. So I think we need to look at amounts of resources pumped into R&D. But this isn't a limitless range. So we have now button sized batteries CO2 lithium producing something like 500wh/kg (Id need to look it up again), theoretical limit of 1875wh/kg These have been around for decades but they haven't been able to handle recharge cycles because the carbon gets stuck to the cathode and won't cycle back again from memory its been about a year since I read the abstract of the paper. They claim to have found a way to make this happen and have gotten so far 500 charge cycles (again from memory grain of salt) with maintaining 80% capacity. They are working on pushing this battery up to closer to its theoretical limit (they'll never get there but might get to 800 or 1000), likewise other chemistries like Lithium Sulfur have theoretical limits even higher 2600wh/kg. Again theoretical not necessarily practical. But that does give some scope now that R&D in the billions is being pumped in to make gains and win the battery war so to speak. Some of the Sodium sulfur batteries are already at 500wh/kg and claiming to be heading towards 1000wh/kg. So we'll once we get to around 800wh/kg we will have a viable paddock basher on pure electric, but not a cross country machine unless we want to loose power to weight and accept performance like a direct drive VW. That would suit me just fine the paddock basher. I never really flew much more than 40-45 minutes at a time anyway. Anyway we'll have to wait and see. But yes we are a way off yet and nothing is certain.

Consider cost of fuel though. Here in OZ I just paid almost $2/litre forget oil etc. If I only want a paddock basher at some point the cost to charge which is next to nothing for any electric craft. They will be here eventually. I suspect sooner than people realize but probably not for 8 years. Too much money being poured and and fairly consistently making improvements its a fairly steep curve in terms of energy density once they start approaching practical limits that curve will shallow.its pretty steep still. Loads of companies failing of course for various reasons but enough are making progress to keep that curve steep for the time. So I suspect on that basis good progress will continue for another few years at least.

Just blow out the air filters and walk around the machine, kicking each tire as you go.... Aaaaaand...

Voila... service complete!

Honestly, I keep her in a custom built humidity controlled hangar. I fly once or twice a month for an hour at a time.
I don't break open an engine ever and keep all fluids and rubber checked on by using the squish test before I fly.
Here in the tropics rubber stays rubber for a long time.
At this rate I have just hit 35 hours on my brand new 582 blue head.
Gonna take for ever to hit 300....

Don't stress, this engine is surprise less, and it is one of the best ultralight engines ever made, you have 2 ignitions completely independant

this engine tells you all ... get the gyro out of the hangar, start it , warm it up, then progressively increase rpm, check if at 5600/5700 rpm the egt's are ok (this is the worst rpm because the jet needle are still in the needle jet)

If it is ok, it shows that your engine is sealed and that the right mix is coming in ... most of the people test the egt's full throtle but it is not a good test because at full throttle the needles are out if the needle jet and iand the egt's are generally righ .. so the test is relevant at 5600 rpm not at 6500 rpm .

then stop the engine and look for leaks, because a cold engine never leaks a lot and can start leaking oil , fuel etc after it is on pressure

often change the carburator subber skirts ... I fuckin dont know the name of it ... those are the rubber large and short tube that are securing the carbs on the engine, do it every year (whatever the flight hours), check the clamps are tighten etc

change the carb filter and keep exactly the same then you had before, the fuel/air mix could be modified

change the spark plug often

often balance your carbs to avoid shock on you engine at low rpm

test your ignitions before taking off ..

remove your cylinder head at 250 hours and check the state of the cylinders

Run your engine for 500 hours before hoverhaul 300 hours is stupid ...

you have a really good engine ... the only issue it that it is thristy

Salut Cameron,
We can fly our gyros level and see what is their rpm at best glidding speed, it will tell us how much power is needed to sustain the fligh on
I don't really believe in calculations, at least in my capcity of calculating properly,
of course we must reduce wieght, I manage to make a tanden weighting 235 kilos, certainly a bit less , but I could have gone down to 220 kilos using titanium screws of aluminium screws everywhere there it no efforts, and paying more attention to reduce resin/fibers ratio.
I am convinced that it is possible to get rid of my turbocharge kit (12 kilos in all), then use only my 80hp to fly (it is enough for a tandem, non sportive) and then add a small degree of hybridation to get the extra 50 HP to fly level (I am sur this is enough)and to give a few minutes boost .. it is clear thatr it would bea good challenge and it would give me a good experience

as for the batteries, I hops they will better but I am skeptical because I have been waiting long and they did not evolved as fast as people were saying they would better

cheers

jmi

Gudday, Hope you had a good Christmas.

On batteries, yes you are right to be skeptical. I am optimistic in the long term skeptical in the short. Especially on any one promise but if you look at the graphs over the past 20 years they show a pleasing upward trend and a pretty straight trend line. The straightness of the trend line is what I am paying attention to as it indicates steady upward progress. If we were running up against practical (not theoretical limits) we'd be seeing that trend line start to flatten out thus far it keeps going up in terms of Kwh/kg so I think we will make progress. Consider the original Nissan Leaf when it came out it had 90mile range now for the same weight battery that is 168 miles. So we are making progress but yes not as fast as any of us would like. I finished span wise balancing my rotors today will now have to double check the chordwise balance. I had to add a fair bit of clear coat to one rotor and while I tried to keep it along the chord line as much as possible its likely way out which will mean adjusting and then re-spanwise balancing. still we are slowly getting closer to getting them up in the air again.

hello mate,

on batteries I have to say that what we already have is enough to begin working, My small experience in batteries (2 motorbikes) has proven that it is possible to use them but that we really must take them for what they are and not for what we want them to be.

they are limited in capacity, their capacity going down in times, they are complicated to use (BMS, risk of fire etc) ...

But on the other hand, good and cheap BMS , Good an programmable Controller exists and are available, and batteries are availables.. provided we make an effort to build up proficiency in this field we can make packs, repair packs, program conntroler to protect then batteries, use the brushless easily either as motors or generators all of thins without having to design the tools.

all of this only became possible in the 5 lasts years ...

I think that I will end up with a good pre-rotator and that this experience will open to me the doors of a future parallel engine hybridation ressebling the video you showed us .

it would be a dream to already have the possibility to keep an electric booster

it would make it possible to downsize the fuel engine and also to have a double chance to survive in case of a fuel engine failure

I am more then excited to be honest

as for your rotor I can't wait to see it mate ... I love people how make things happen ..

Hey there,

hope you had a good new years eve.

all sensible stuff on batteries. I agree we are looking at years for a proper battery (solid state) probably 6-8 for an acceptable paddock basher. And yes that hybrid looks awesome the same company is using very innovative approach for their Merlin ultralight also check this out.https://www.youtube.com/watch?v=Gaah_1WBViU&t=124s this is the kind of thinking we need.

On rotors. I got my blades spanwise balanced perfectly yesterday, and I mean perfect I got them to 0.00 degrees on two digital scales so perfect that one tiny 1/4 inch washer shifted it to 0.2 - 0.3 degrees. However because I'm repainting these not building from scratch the normal process would be span balance them then slide on the chord weights. This order works because the chordweights are identical and bolted in the same spot. However as I'm re-painting I had to chord balance them first then try to concentrate the paint around the center chord which I did but it ended up biasing it WAY too far forward so now one blade is massively overbalance chordwise. So it's back to sanding off a great deal of clear coat getting it back into chord balance then trying to get the span balance back again. I can see I'm going to be going backwards and forwards again and again. On the bright side I weighed my wood rotors 18.5 kg all up, most blades out there at the same size are 27kg+ I always knew they were light but didn't expect them to be that light or the metal blades to be that heavy. Also a positive I made a nice 3D rotor balance jig incorporating skate bearings works a treat which is good because it looks like I'll be needing it again and again as I get closer to both proper span balance and chord balance over what I figure will probably be a week of fucking around. Sigh.