# Another aircraft motor



## billfunk29 (Apr 24, 2019)

Is MagniX part of Magnax?
https://www.magnax.com/magnax-blog/a-new-generation-of-axial-flux-ev-motors
Axial flux has potential for much higher specific HP than radial flux. Also has some advantages for dumping heat.


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## brian_ (Feb 7, 2017)

billfunk29 said:


> Is MagniX part of Magnax?
> https://www.magnax.com/magnax-blog/a-new-generation-of-axial-flux-ev-motors


I assume not - it's just obvious to use "mag" in the name of anything involving magnets (electromagnets or otherwise), and to end techie names with "x".

Magnax is in Belgium and actually sells motors; MagniX is an Australian-American startup. There's no overlap in staff and they don't mention each other in their websites. It's just bad (or intentionally confusing?) branding by MagniX.



billfunk29 said:


> Axial flux has potential for much higher specific HP than radial flux. Also has some advantages for dumping heat.


Magnix provides no information about their design, but from the images (which appear to be just renderings, not real photographs) they appear to be using a large-diameter radial flux design. It looks like it probably has a high pole count and perhaps surface-mounted permanent magnets to keep the flux path near the rotor surface and allow for a mostly hollow rotor.


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## PhantomPholly (Aug 20, 2008)

Makes perfect sense for short hops. If they pallatize the batteries, they can "refuel" in minutes (leaving the pallet slow-charging while they make the next round-trip flight).


From a maintenance perspective, electric will make things much simpler. Motor not working? Swap it out in under an hour. With the good torque of electric motors they can stick with fixed pitch props for short hauls, also simpler and cheaper.


It's only going to get better.


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## brian_ (Feb 7, 2017)

PhantomPholly said:


> Makes perfect sense for short hops. If they pallatize the batteries, they can "refuel" in minutes (leaving the pallet slow-charging while they make the next round-trip flight).


I don't know where they intend to put the battery packs in the DHC-2 Beaver (or even if they have thought that far ahead), but obvious locations would be in place of the multiple separate belly-mounted fuel tanks. Making packs in those locations accessible enough for routine swaps seems like a structural challenge.

Battery swapping often sounds like a good idea, but rarely works out when all of the details are considered. For instance, the battery packs will likely have circulating liquid for thermal management, so swapping would involve disconnecting and reconnecting at least two fluid connections per pack. Then of course in this case the aircraft are on floats - not amphibious, and not floats with wheels - so all operation is on the water and a battery swap would have to be done while bobbing in a saltwater harbour.



PhantomPholly said:


> From a maintenance perspective, electric will make things much simpler. Motor not working? Swap it out in under an hour.


In a car, sure. On a commercial aircraft, the inspection and testing process alone will likely take much more than an hour. Fortunately, motor failures are very infrequent.  It's the battery and the electronics which will fail.



PhantomPholly said:


> It's only going to get better.


Yes, but at the moment the target application hasn't even been shown to be workable.


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## PhantomPholly (Aug 20, 2008)

brian_ said:


> I don't know where they intend to put the battery packs in the DHC-2 Beaver (or even if they have thought that far ahead), but obvious locations would be in place of the multiple separate belly-mounted fuel tanks. Making packs in those locations accessible enough for routine swaps seems like a structural challenge.


We had 18-year old crew chiefs swap out belly tanks in minutes 35 years ago. I agree there are challenges, but hardly insurmountable.



> Battery swapping often sounds like a good idea, but rarely works out when all of the details are considered. For instance, the battery packs will likely have circulating liquid for thermal management, so swapping would involve disconnecting and reconnecting at least two fluid connections per pack. Then of course in this case the aircraft are on floats - not amphibious, and not floats with wheels - so all operation is on the water and a battery swap would have to be done while bobbing in a saltwater harbour.


Cooling for batteries is far lower pressure than what happens in your radiator with steam pressures. Quick connect garden hose adapters are quite easy to connect and disconnect, don't leak much to speak of, and a generous overflow tank can assure enough cooling for a 15-20 minute flight even if a sizeable leak occurs.



> In a car, sure. On a commercial aircraft, the inspection and testing process alone will likely take much more than an hour.


Have you ever flown on micro airlines with plains like TwOtters (twin otters)? LOL - this would be such a step up in simplicity and reliability it would seem like magic to them.....



> Fortunately, motor failures are very infrequent.  It's the battery and the electronics which will fail.


Batteries don't generally fail all at once, and you can install a "cross feed" type of system to bypass one of x packs in the event of an actual failure. Again, with 15-20 minute hops that seems like a very small concern. The electronics are another story - however, if your motor is designed as if it were several separate motors in parallel, each can have its own controller so if one fails the others take it up.

A very common scenario in aviation is twin motors driving a common shaft, as in helicopters. If Turbine Aeronautics is successful in delivering their engines to market, I plan to upgrade my baby Lancair to a Velocity and replace the Lycosaurus with a "twin engine single prop" setup where each motor has a sprag clutch in the pulley so that either motor can freewheel while the other pulls full load. The same approach can be used with multiple electric motors. If driving a fixed pitch prop, it would be virtually fail-proof. Edit: Photo is a twin PT-6 turboprop transmission, to give you an idea of how it can work. Same thing can be done with electric motors.










> Yes, but at the moment the target application hasn't even been shown to be workable.


Meh, don't be a buzzkill... Each component has been proven. Plug them all together, and voila'!


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## brian_ (Feb 7, 2017)

PhantomPholly said:


> We had 18-year old crew chiefs swap out belly tanks in minutes 35 years ago.


They did this for every flight, the tanks weighed as much as battery packs, and they did it while standing on the floats of floating aircraft during boarding? Wow, I'm impressed... but the new crews will need to be faster. 



PhantomPholly said:


> Cooling for batteries is far lower pressure than what happens in your radiator with steam pressures. Quick connect garden hose adapters are quite easy to connect and disconnect, don't leak much to speak of, and a generous overflow tank can assure enough cooling for a 15-20 minute flight even if a sizeable leak occurs.


This appears to assume that routine spillage during swaps - directly into the ocean - and substantial routine leakage in operation of glycol coolant is acceptable. It certainly would have been when these aircraft were new, but it isn't now.



PhantomPholly said:


> Batteries don't generally fail all at once, and you can install a "cross feed" type of system to bypass one of x packs in the event of an actual failure. Again, with 15-20 minute hops that seems like a very small concern. The electronics are another story - however, if your motor is designed as if it were several separate motors in parallel, each can have its own controller so if one fails the others take it up.


I wasn't meaning to suggest that battery reliability is a concern, only that ease of changing motors is unimportant because motor reliability is even less of a concern. Complete redundancy in the power path to the motor (the dedicated controllers) should be assumed.



PhantomPholly said:


> A very common scenario in aviation is twin motors driving a common shaft, as in helicopters. If Turbine Aeronautics is successful in delivering their engines to market, I plan to upgrade my baby Lancair to a Velocity and replace the Lycosaurus with a "twin engine single prop" setup where each motor has a sprag clutch in the pulley so that either motor can freewheel while the other pulls full load. The same approach can be used with multiple electric motors.


By "very common" I think you mean "only on multi-engine helicopters". 

While it would work, this seems silly to me for electric motors. Just use a dual stator windings and separate controllers, like the Siemens motor which was discussed earlier. There is no need for the mechanical complication of clutches, or even more than a single shaft. But the "twin engine single prop" Lancair would be interesting.  On the other hand, an aircraft properly designed for the powertrain and service would be better... which means wing-mounted motors and props, just as de Havilland realized in making the Twin Otter from the Otter.

Having observed this obvious solution, I'll note that it isn't mentioned on the MagniX website. It's not clear to me that this aviation-only company knows anything about aviation.


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## PhantomPholly (Aug 20, 2008)

brian_ said:


> They did this for every flight, the tanks weighed as much as battery packs, and they did it while standing on the floats of floating aircraft during boarding? Wow, I'm impressed... but the new crews will need to be faster.


You shouldn't post while you're stoned unless you offer to share. 

I flew F-4E Phantoms, land based. A specialized jack was used to move and hoist the tank, it was a piece of cake.




> This appears to assume that routine spillage during swaps - directly into the ocean - and substantial routine leakage in operation of glycol coolant is acceptable. It certainly would have been when these aircraft were new, but it isn't now.


Glycol is not an ecological hazard. It evaporates and breaks down naturally.




> I wasn't meaning to suggest that battery reliability is a concern, only that ease of changing motors is unimportant because motor reliability is even less of a concern. Complete redundancy in the power path to the motor (the dedicated controllers) should be assumed.


Yep, my only point was that pretty much everything about electric is more reliable, and can in the same space as a Lycosaurus (refit) be made redundant.





> By "very common" I think you mean "only on multi-engine helicopters".


No, not just there but yes, that is very common. Given that these units produce only 17% of the power of a PT6, developing a twin gearbox should not be particularly challenging.




> While it would work, this seems silly to me for electric motors. Just use a dual stator windings and separate controllers, like the Siemens motor which was discussed earlier. There is no need for the mechanical complication of clutches, or even more than a single shaft. But the "twin engine single prop" Lancair would be interesting.  On the other hand, an aircraft properly designed for the powertrain and service would be better... which means wing-mounted motors and props, just as de Havilland realized in making the Twin Otter from the Otter.


Yes, I was primarily talking about refits. Actually, an electric motor COULD suffer bearing failure, which speaks positively to a dedicated power shaft with n motors driving it. Getting into the 0.0000001% range of what iffing here. Sprag clutches are not "complicated," and given that they work just fine on helos it seems like it is tried and true. Ultimately I'd love a pair of 200hp microturbines on a Raptor. You could mount a PT-6, but it would use so much fuel it would literally suck the fun out of the aircraft and be too overpowered.




> Having observed this obvious solution, I'll note that it isn't mentioned on the MagniX website. It's not clear to me that this aviation-only company knows anything about aviation.


Shocker. An engineer, upon learning the power to weight ratio of his creation, immediately assumes it is suitable to an aircraft. Google "Subaru Aircraft Conversion" for a good laugh.


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## brian_ (Feb 7, 2017)

*Updates*

The Harbour Air conversion is progressing, with a test flight scheduled for this month. They expect a ten-minute flight to start, which seems reasonable.
_Seaplane to ePlane: Flight Test Confirmed_


> We are thrilled to announce, following the successful installation and testing of the magniX propulsion system, our incredible maintenance team along with our partners have reached the next level of critical milestones.
> 
> Harbour Air and magniX will unveil the world’s first Beaver seaplane retrofitted with a 750 horsepower all-electric magni500 propulsion system for the inaugural test flight on Wednesday, December 11. The prototype will take flight from our Richmond (YVR South) location. Please see below for a highlight of the work and efforts completed to date as well as next steps to take us to this pivotal moment in aviation history.
> 
> ...


Video from Harbour Air: https://www.youtube.com/watch?v=npHDNXOt7PE
In the video, it looks like they might have placed the battery in the cabin, which is not feasible for commercial service... but it's not clear.

So they are taking this way past a simple PR stunt, although we won't know for years when - or whether - they will get past a single aircraft.

There was discussion earlier of a combining gearbox. Like other aviation motors, this one is direct-drive, so dual motors just means two motors on a common shaft - no gearbox at all. They refer to it as a single MagniX 500 motor, but in the MagniX product page this is clearly two MagniX 250 motors on a common shaft with joined housings. That works  They describe it as "4x3-phase", with four sets of windings (two sets in each of the two motors) which are separately powered for redundancy; this feature was not included in the version of the MagniX product page back in May when I started this thread.

MagniX has apparently been working with various companies attempting to launch electric aircraft, so some MagniX motor somewhere is probably now flying... just not in a production aircraft, or in even a single test unit in commercial operation.

I had mentioned Viking, the type certificate owner. As the OEM they are supporting the existing fleet and providing technical support to operators and those making modifications to aircraft, but in the case of the Harbour Air Beaver this is the extent of their involvement at this point. It should be interesting to see what Viking comes up with themselves in electric power.

Harbour Air expects to spend two years in testing and regulatory approval before making their first commercial flight.


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## brian_ (Feb 7, 2017)

*First flight success*

Harbour Air has completed the conversion to a flyable state, and uneventfully completed a first test/demo flight:
Harbour Air and magniX Announce Successful Flight of World’s First Commercial Electric Airplane

This flight is getting substantial media coverage and social media discussion.

Strangely, some articles quote a Harbour Air (or MagniX?) representative as claiming that the motor is the same weight as the original engine, and the battery is the same weight as a full tank of fuel. Both of these would presumably be very rough approximations for the public, since the 135 kg motor plus four 12 kg controller/inverters cannot possibly weigh as much - even with mounts and supporting equipment - as the 290 kg (dry) engine; my guess is that the total electric powertrain weight (of motor, controllers, etc. and battery) are close to the weight of the total stock powertrain weight (of engine, accessories, oil, etc. and full fuel load). That stock total would be well over 755 kg (just the total of the dry engine, oil, and fuel).


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## kennybobby (Aug 10, 2012)

This is exciting and would love to see it, but the video was marked as private...

What is the typical range of the ICE planes versus what they expect with electric.


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## brian_ (Feb 7, 2017)

kennybobby said:


> This is exciting and would love to see it, but the video was marked as private...


That's strange. I didn't even see a video on the announcement page. The video in Twitter on the live video stream News page works for me, but the quality is really low.

The MagniX news page is full of coverage of this flight, some with videos, presumably from different sources.

One active subject of social media discussion is whether the aircraft is quiet, based on the questionable audio in those videos.


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## brian_ (Feb 7, 2017)

kennybobby said:


> What is the typical range of the ICE planes versus what they expect with electric.


Beavers are used as bush planes, operating into remote and unserviced locations. They can carry more than half a ton of fuel, so if the operator is willing to give up much of the potential passenger and cargo load to carry that fuel, they can have hours of endurance and 732 km (455 miles) of range... maybe less with the floats.

Harbour Air only runs short hops between harbours in the Vancouver area, over on the east side of Vancouver Island, and up the Sunshine Coast, so none of their flights are more than half an hour. The routes covered by the Beavers (they also have some larger turbine-powered aircraft) are the shorter ones, so they say that can cover all of those with a 110 km (70 mile) range... and that's all they expect of the electric Beaver. The number being tossed around is 30 minutes of endurance plus a 30 minute reserve, at cruise power (not the whole 750 horsepower!). Harbour Air still has not published any specs, and it's not certain that they have the full battery capacity installed yet.

The motor manufacturer - magniX - talks about up to 1000 miles of range, but that's entirely dependent on battery and would be impossible in a converted Beaver, which couldn't possibly carry enough battery weight for more than a quarter of that. They are also the motor supplier for Eviation, which is going for that sort of range with their composite-construction all-new design, called the Alice.


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