# Thinking ahead - aircraft motors



## PhantomPholly (Aug 20, 2008)

In the Solitron Jr. thread I was reading that Jr. is good for powering 200hp continuously. What DC motors (if any) out there can produce 200hp continuously? Also, would arcing be a problem for DC motors at high altitude where the air is thinner?


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## piotrsko (Dec 9, 2007)

don't know about the DC motors, but I do remember my magneto's arced like crazy above 15000 (not that I was supposed to be up there). Most of the EV planes I've seen via the EAA don't go that high or use odd motors.


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## PhantomPholly (Aug 20, 2008)

piotrsko said:


> don't know about the DC motors, but I do remember my magneto's arced like crazy above 15000 (not that I was supposed to be up there). Most of the EV planes I've seen via the EAA don't go that high or use odd motors.


Yeah, I think they focus on AC motors so they can run "brushless."

Your magnetos shouldn't be arcing at only 15,000' - in WWII fighter planes using the same technology flew to over 30,000' without difficulty and I routinely fly that high with no trouble (only one mag, replaced the right with electronic ignition). But, I'd be curious to know how you knew they were arcing, or why you would say that you shouldn't be up there (that's usually still VFR airspace)? Is it an ultrlight? Well maybe best you not say since this is a public forum...


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## jehan12413 (Feb 4, 2010)

O2 requirements maybe!


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## RE Farmer (Aug 8, 2009)

PhantomPholly said:


> Yeah, I think they focus on AC motors so they can run "brushless."
> 
> Your magnetos shouldn't be arcing at only 15,000' - in WWII fighter planes using the same technology flew to over 30,000' without difficulty and I routinely fly that high with no trouble (only one mag, replaced the right with electronic ignition). But, I'd be curious to know how you knew they were arcing, or why you would say that you shouldn't be up there (that's usually still VFR airspace)? Is it an ultrlight? Well maybe best you not say since this is a public forum...


High altitude aircraft engines deal with arcing one of two ways - usually they use pressurized magnetos or might also design larger mag's which have increased distances between the (distributor block's) electrodes for the various cylinders combined with small plug gaps (to make it easier for the spark to occur where it's supposed to, i.e. in the combustion chamber).


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## PhantomPholly (Aug 20, 2008)

RE Farmer said:


> High altitude aircraft engines deal with arcing one of two ways - usually they use pressurized magnetos or might also design larger mag's which have increased distances between the (distributor block's) electrodes for the various cylinders combined with small plug gaps (to make it easier for the spark to occur where it's supposed to, i.e. in the combustion chamber).


That may be true - but in general anything below 25,000' isn't considered "high altitude." I routinely fly up to 17,500' without any evidence that my mag is arcing.


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## RE Farmer (Aug 8, 2009)

PhantomPholly said:


> That may be true - but in general anything below 25,000' isn't considered "high altitude." I routinely fly up to 17,500' without any evidence that my mag is arcing.


Not sure if magnetos are OT, but there are many variables that go into whether arcing will occur. Yes, altitudes <18,000' may not be considered to be high alt., but neither are they necessarily low altitude. I think many if not most aircraft engines designed for use above 12,000' (i.e. turbocharged) have pressurized mags. I'm not sure but that might be the difference. Non-turbo engines would have low cylinder (manifold) pressure and may not experience arcing for that reason - whereas a turbo'd engine could if the mag wasn't pressurized also. Since you have one mag and one electronic ignition, I might assume you're flying an amateur(home)-built craft in which case it would depend on the components you selected for your engine.

More On-topic: I'm considering installing electric drive to my homebuilt rather than the ICE in the original plans. However, I'm not planing to use it over 10,000' so I don't think I'll need to worry about arcing. Are others here thinking about installing electric drives in their aircraft?


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## piotrsko (Dec 9, 2007)

well: no o2, service ceiling was 12000 (1930 technology), and the engine misfired something fierce, found burned stuff inside the mag when I got down and tore it apart. BTW way above 15000 in a thermal.

i'm thinking something with advanced brushes or interpoles probably should be OK, but not a 36v forklift motor running on 300v.

I also only used max throttle at takeoff, usually only 65% during normal flight so perhaps 50 hp would be enough if over amped for takeoff?


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## Sunking (Aug 10, 2009)

There is just something not right about an electric airplane. I wouldn't step 1 foot in one.


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## RE Farmer (Aug 8, 2009)

Sunking said:


> There is just something not right about an electric airplane. I wouldn't step 1 foot in one.


Why is that?

As an Ev'er, you know about the MUCH greater reliability of an electric motor over ICE. The lower noise and vibration are less fatiguing on both the people and the airframe. Then there's the lower cost of operation (fuel, oil & maintenance).

And a farfetched reason - electric aircarft can't be used as a flying bomb , therefore would be better for national security.


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## PhantomPholly (Aug 20, 2008)

RE Farmer said:


> Not sure if magnetos are OT, but there are many variables that go into whether arcing will occur. Yes, altitudes <18,000' may not be considered to be high alt., but neither are they necessarily low altitude. I think many if not most aircraft engines designed for use above 12,000' (i.e. turbocharged) have pressurized mags. I'm not sure but that might be the difference. Non-turbo engines would have low cylinder (manifold) pressure and may not experience arcing for that reason - whereas a turbo'd engine could if the mag wasn't pressurized also. Since you have one mag and one electronic ignition, I might assume you're flying an amateur(home)-built craft in which case it would depend on the components you selected for your engine.


That sounds right, I've heard of pressurized mags but also know many aircraft without turbos flew in WWII. I have one of these (sample photo, not mine), and one day would love to strip the ICE and go electric. So, in seeing Solitron Jr. advertised as 200hp continuous I started thinking...  That, BTW, would be 40hp more than I currently have at Sea Level on a "standard day" (which almost never happens in Atlanta). I suspect I'd see over 2,000'/min climb with 200hp constant power...



> More On-topic: I'm considering installing electric drive to my homebuilt rather than the ICE in the original plans. However, I'm not planing to use it over 10,000' so I don't think I'll need to worry about arcing. Are others here thinking about installing electric drives in their aircraft?


See above - yes very much so but not until the range issues are solved. I would settle for a bit more weight (not much) to retain my 1,000 mile range. Electric would have another advantage in that I could completely close out the cowling (or, simply have very small "blast tubes" for cooling). That means that I would have less drag at the same airspeed, which would make up some for the extra battery weight.

But, it will have to wait until some of the infrastructure starts getting built out to accommodate electric. "Around the lake" planes are no problem, but for a cross-country plane you need to know you can charge up at your destination...


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## PhantomPholly (Aug 20, 2008)

RE Farmer said:


> Why is that?
> 
> As an Ev'er, you know about the MUCH greater reliability of an electric motor over ICE. The lower noise and vibration are less fatiguing on both the people and the airframe. Then there's the lower cost of operation (fuel, oil & maintenance).
> 
> And a farfetched reason - electric aircarft can't be used as a flying bomb , therefore would be better for national security.


Anything can be used as a weapon.

But, you are more right about reliability than you know. Many failures BESIDES the engine are caused by ICE engine vibration - gets expensive when a $10,000 radio takes a nap because of too much shaking... 

Electric will be a HUGE improvement. Since electric creates full hp over a wide range of RPM, it virtually eliminates the need for a variable pitch propeller. Simply pitch the prop so that during climb you only turn 1/2 of max rpm - you will still be making nearly full hp. At cruise, just let the rpms climb. As they increase, the prop provides more resistance until it balances drag against torque.


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## piotrsko (Dec 9, 2007)

OK, now to the hard questions: How much KWH can you put in there, and about how much energy do you need for 1000 mi with reserves?? a BTU derived from gallons burned conversion is in order. batteries in the wings?

Never saw an airfield that couldn't run 110 out to the plane, 220 meant you have to find a mechanic/hangar.

I'm guessing a Lanc 235 or the next one up in the line? opening up the wings will be a real joy.


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## Sunking (Aug 10, 2009)

RE Farmer said:


> Why is that?
> 
> As an Ev'er, you know about the MUCH greater reliability of an electric motor over ICE. The lower noise and vibration are less fatiguing on both the people and the airframe.


Not speaking so much as reliability, but useful fuel load, range, and reserves to be practical. Battery energy densities just are no where close to being practical for electric aircraft in my opinion. 

EV motors at cruise speed are a lot like their ICE counterparts in that they only require 10 to 20% of their full power rating. However aircraft engines and motors need to run at 70 to 90% full power at cruise and thus use substantially more power for a given weight.


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## RE Farmer (Aug 8, 2009)

PhantomPholly said:


> That sounds right, I've heard of pressurized mags but also know many aircraft without turbos flew in WWII. ... I suspect I'd see over 2,000'/min climb with 200hp constant power...
> 
> ... Electric would have another advantage in that I could completely close out the cowling (or, simply have very small "blast tubes" for cooling). That means that I would have less drag at the same airspeed, which would make up some for the extra battery weight.
> 
> But, it will have to wait until some of the infrastructure starts getting built out to accommodate electric. "Around the lake" planes are no problem, but for a cross-country plane you need to know you can charge up at your destination...


RE: WWII engines - most combat aircraft were supercharged in some form (turbo or gear driven) to perform at altitude or just make more hp for given size engine. However, reliability was low - Mustang's Merlin had 500hr TBO.
An electric aircraft (EA) motor would benefit you in two ways - first, you've already noted is significantly reduced cooling drag and its associated other heat problems. Second, hp is maintained with altitude - effectively acting like a "turbocharged" aircraft. 

RE: infrastructure - springing for the cost of hangaring for the night would gain you access to power for charging, quite possibly 220V as most shops have large air compressors or welders that require it. Many FBOs have let me plug in my RV when at their field. (but then I was buying 100's of gallons of avgas for my WWII aircraft, an SNJ/AT6.)


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## RE Farmer (Aug 8, 2009)

piotrsko said:


> OK, now to the hard questions: How much KWH can you put in there, and about how much energy do you need for 1000 mi with reserves?? a BTU derived from gallons burned conversion is in order. batteries in the wings?
> 
> Never saw an airfield that couldn't run 110 out to the plane, 220 meant you have to find a mechanic/hangar.
> 
> I'm guessing a Lanc 235 or the next one up in the line? opening up the wings will be a real joy.


You're right, Piotrsko, stored KWH is an issue just yet but won't be for long. However, I expect significant improvement soon. I just a few years I've effectively doubled or even quadrupled my expected range for my MG. More than 20miles was unrealistic using Pb in it. Now, with LiPO4, I can easily expect 60mi. or more if I'm willing to give back the trunk space I gained by changing battery type. Better chemistries are on the way now that it's of commercial interest to auto and renewable energy companies. I can't say for sure but Moore's Law may apply to energy storage as well as transistors for processing power.

Putting storage lockers in the wing is definitely possible provided structural integrity is maintained. And for efficient craft like Phantom's Lancair, and hour to two endurance can get you 200-500 miles "down the road". While not exactly transcontinental, I would call that cross country range. Besides, these days my bladder doesn't last any longer than a few hours.


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## Sunking (Aug 10, 2009)

RE Farmer said:


> You're right, Piotrsko, stored KWH is an issue just yet but won't be for long. However, I expect significant improvement soon. I just a few years I've effectively doubled or even quadrupled my expected range for my MG.


That is still not enough IMO. Right now LFP is what? At best case 0.72 MJ/Kg compared to gasoline/diesel of 46 MJ/Kg. I hope to live long enough to see it, but I am not holding my breath nor would I wager my grand children would see it.


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## aeroscott (Jan 5, 2008)

what is it going to take to cruse at the low cruse 50% power level . Most of the aircraft engines don't make advertised power(engines tested without exhaust systems ) , who knows what the real power is at 1/2 power . how much thrust is developed ? thrust moves the airplane not hp . Hopefully ev power will need to be somewhat less then gas numbers would indicate .


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## RE Farmer (Aug 8, 2009)

Sunking said:


> That is still not enough IMO. Right now LFP is what? At best case 0.72 MJ/Kg compared to gasoline/diesel of 46 MJ/Kg. I hope to live long enough to see it, but I am not holding my breath nor would I wager my grand children would see it.


That's the energy content of the fuel. In terms of fuel doing actual work it's more like 10MJ/Kg (3 KWH/Kg) for a perfectly tuned test stand engine. That's 30X large prismatic LiPO4 cells (~100 WH/Kg). If Moore's Law were to hold for electric energy storage, we will have effective parity between liquid fuels and electric storage in 10 years. I think that's within OUR lifetime and certainly with our children's.

OTOH, the motor would be ~100Kg less the ICE. Typical small aircraft has 200 Kg Ice plus 150 Kg (~50gal) fuel load; that's ~82KWH assuming 100Kg for motor/controller, etc. for current off the shelf components. Ignoring performance improvements available from electric power as discussed previously.

Further, electric power has the advantage of high torque at low RPM; the most efficient thrust comes from slow turning, large diameter props/fans. That's why modern jet engines (747, 777) have the size/shape they do vs. small diameter pods of the 1960's (727, DC9).

So Phantom, better start thinking about conversion for your Lancair. The EPA & FAA want to get rid of 100LL fuel soon anyway.  

Edit: I'm planning on skipping the ICE for my current airplane build project (Avid Amphibian) and going straight to electric - but first I need to get the MG done for my wife. She want to show it off to her friends.


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## RE Farmer (Aug 8, 2009)

Here are some reference sites for those wanting more info on electric aircraft:

http://cafefoundation.org/v2/ea_eas_2010_main.php

http://lindberghprize.org/about-csa/

http://www.electraflyer.com/

http://www.kitplanes.com/magazine/engines/176-1.phtml

Electric Cessna 172: http://www.byeenergy.com/pages/

http://www.sonexaircraft.com/research/e-flight/


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## PhantomPholly (Aug 20, 2008)

piotrsko said:


> OK, now to the hard questions: How much KWH can you put in there, and about how much energy do you need for 1000 mi with reserves?? a BTU derived from gallons burned conversion is in order. batteries in the wings?
> 
> Never saw an airfield that couldn't run 110 out to the plane, 220 meant you have to find a mechanic/hangar.
> 
> I'm guessing a Lanc 235 or the next one up in the line? opening up the wings will be a real joy.


Lancair 320 - the last one was a 235. Very similar.

Opening the wings won't be hard - the wings come off and I can cut out the inboard end of the tank. Tanks are roughly rectangular, so should be able to simply shove batteries up there. Volume per wing is equivalent to 16 gallons of gas. More weight would be less problem there since it will be centered along the axis of lift. There is also a header tank behind the instrument panel that holds 10 gallons.

Range is another issue. At 180mph in its current configuration, I get roughly 27mpg. Some people do a bit better, and I think that with closed / smaller inlets on the cowl it should be possible to get at least the equivalent of 30mpg at that speed. That is probably running about 80hp today. So, the batteries still have quite a ways to go. However, if the motor is smaller / lighter, it may be possible to re-gain some range by including an extra pack in the nose. But at the end of the day weight is still your enemy...


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## PhantomPholly (Aug 20, 2008)

aeroscott said:


> what is it going to take to cruse at the low cruse 50% power level . Most of the aircraft engines don't make advertised power(engines tested without exhaust systems ) , who knows what the real power is at 1/2 power . how much thrust is developed ? thrust moves the airplane not hp . Hopefully ev power will need to be somewhat less then gas numbers would indicate .


Klaus Savier, owner of LightSpeed electronic ignitions (aftermarket for experimental planes) has a VariEze with a 100hp motor and gets about 100mpg. More can be done with aerodynamic cleanup and a willingness to accept slower top end than with horsepower.

Figure "reasonable" economy fuel burn of ~6gph in my Lancair is nearly 30mpg. Best economy is probably at about 150mph, 5gph. I'm sure I could improve that with some aerodynamic cleanup (gap seals, other tricks).


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## Sunking (Aug 10, 2009)

PhantomPholly said:


> Lancair 320 - the last one was a 235. Very similar.


It has been 28 years since I was last current, but if I remember correctly the 320 was a hot little kit plane with a cruise speed of 200 Knots? That is better than the Mooney which I believe is the fastest manufactured single engine civilian plane? Is the 320 cabin pressurized?


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## PhantomPholly (Aug 20, 2008)

Sunking said:


> It has been 28 years since I was last current, but if I remember correctly the 320 was a hot little kit plane with a cruise speed of 200 Knots? That is better than the Mooney which I believe is the fastest manufactured single engine civilian plane? Is the 320 cabin pressurized?


No cabin pressure. I do use O2 for higher altitudes (portable system, pulse-demand regulator and just cannulas not full mask). I can get close to 200kias down very low, but get beat up down there so generally accept a slightly slower cruise for greatly improved mileage up high. Usual cruise is right at 200mph, which is LOP (Lean of Peak - best efficiency for a given power setting for non-aviators on the board) between 9,000' - 14,000', slowing a bit at the higher altitude unless I'm willing to use more power.

Some of the high-compression 360's see over 200ktas. I suspect mine is a bit heavier than optimal (I didn't build it) and maybe not as clean as some - something to work on over the coming years.

Edit - you should look into the new sport class category. All you need is a valid drivers license and a biennial review to become current again. A bit slower, but still fun.


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## Sunking (Aug 10, 2009)

PhantomPholly said:


> Edit - you should look into the new sport class category. All you need is a valid drivers license and a biennial review to become current again. A bit slower, but still fun.


Can you expand on that please?

Shows how long I have been out of it. I really loved flying even though it was just a C 172. I took up flying right out of college. Then I did something stupid. I got married, had kids, starting saving money and investing, and got serious about my career path. So the flying had to go, couldn't afford it any more. I will never make that mistake again. 

On the serious side since all the kids are grown and gone, I have considered picking it back up again. But as I talk to friends who fly, it sounds like it has really gotten expensive and most have their planes for sale. 

Is AV gas really $7/gal? 
Can you still use regular unleaded? When I last flew the FAA had a certification that would allow you to burn regular unleaded fuel from any gas pump. Has that gone away? The boys tell me there is only 1 refiner of AV gas and with lower demands and even fewer supplies they can pretty much charge whatever they want. That would sure drive me to consider a a C 172TD


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## RE Farmer (Aug 8, 2009)

Sunking said:


> Can you expand on that please?
> 
> ...
> Is AV gas really $7/gal?
> Can you still use regular unleaded? When I last flew the FAA had a certification that would allow you to burn regular unleaded fuel from any gas pump. Has that gone away? The boys tell me there is only 1 refiner of AV gas and with lower demands and even fewer supplies they can pretty much charge whatever they want. That would sure drive me to consider a a C 172TD


OT: Avgas in my region is ~$5. Mogas can be used for older 80 octane (low compression) engines. STC paper work available through various outlets including EAA-Oshkosh.

I've thought of converting my Warrior to TD, but they are REAL expensive ~$30,000 plus TBOs and reliability of the companies and their engines are still suspect.

Do go to AOPA or EAA websites and check out sport pilot certificate; might work well for you. Or if you just want some fun flying, try gliders or ultralights/airchairs (google it). I started decades ago in gliders - for $20-30 tow fee you can fly for hours once you gain some moderate skill. Besides, it's even more quiet and vibration free than EV'ing.


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## Sunking (Aug 10, 2009)

RE Farmer said:


> go to AOPA or EAA websites and check out sport pilot certificate;


I did after Philly mentioned it as I could not wait for a reply. Looks like there has been a lot of changes most notable minimum age requirements. Use not to be any as over the years you would here of a 12 to 14 year old pilot pop up once in a while. 

With that said the Sports Class sounds like the old Recreational Class? Am I wrong but are they they same thing just re-marketed with a different name?

Personally I wouldn't have as much as a problem with a TD as with Electric. I mean heck all commercial jets use diesel, well diesel #1 classified as Jet A1 anyway.

I guess what bothers me is the chance of fire. I am not what you would call a true EV'er. Just an EE that likes to modify golf carts and NEV's as I have two of them. The biggest problem is loose hot connections metling wires and failure while out on the road or course with the occasional fire. Carts and NEV's are extremely easy to inspect by just lifting the seat and checking connections. Batteries in wings and other concealed spaces just sounds problematic too me. I just can't get past it. I mean a fire in a EV is one thing as you can stop and get out, but in a plane...


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## Plamenator (Mar 6, 2009)

Maybe it is not totally relevant, but I have heard of electric glider planes in Europe. This is the type with no motor that uses a second plane to lift it up in the sky and then glides down on its own.
In this way you only need a motor+battery that need to last 3-4min so you can gain altitude on your own.
Motor and battery pack can be quite small so no need to put cells in the wings. A possible configuration can be 96V A123 prismatic+Soliton JR+Agni brushless/Kostov 9". Or maybe a dual Agni - not sure what kind of power one would need.


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## PhantomPholly (Aug 20, 2008)

Plamenator said:


> Maybe it is not totally relevant, but I have heard of electric glider planes in Europe. This is the type with no motor that uses a second plane to lift it up in the sky and then glides down on its own.
> In this way you only need a motor+battery that need to last 3-4min so you can gain altitude on your own.
> Motor and battery pack can be quite small so no need to put cells in the wings. A possible configuration can be 96V A123 prismatic+Soliton JR+Agni brushless/Kostov 9". Or maybe a dual Agni - not sure what kind of power one would need.


Yes, there are several out now I believe. Too, a glider doesn't need much in the way of hp - just has to get airborne.

Even 30 min of power is do-able, but of course the more weight you add the less time you glide.


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## piotrsko (Dec 9, 2007)

PhantomPholly said:


> Even 30 min of power is do-able, but of course the more weight you add the less time you glide.



Eh, to a point: Major (general?) Payne has a 2 place something that was water ballasted a couple of hundred pounds when he broke the speed records a couple of years ago. you may come down faster, but you go waaaaay faster/farther. It has been my experience that weight in general aviation has more to do with spar loads and structure, or climb ability than other concerns, based on fairly clean aircraft. My 50 pacer could haul it's own weight, but it was draggy as all getout.


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## PhantomPholly (Aug 20, 2008)

Interesting - I would not have thought ballast would be a "good thing" for a glider.

If that's true, then electric has yet another advantage. Unlike gasoline which is burned to produce power (lowering weight), battery weight remains essentially unchanged due to charge. This is good in aircraft because you need not consider changing center of gravity / "Weight and Balance" due to fuel consumption.


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## Automcdonough (Sep 1, 2010)

Why so concerned with arcing? It's hard to imagine that anyone would use DC for this application.


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## PhantomPholly (Aug 20, 2008)

Automcdonough said:


> Why so concerned with arcing? It's hard to imagine that anyone would use DC for this application.


Simple - DC Motors:


Are cheaper
Are lighter (? - not sure about this)
Work well with less expensive controllers
In an emergency, could be configured to run directly from the batteries (bypass the controller) for On / Off power for redundancy
 Too, I would have concerns about an inverter causing excessive electrical noise (although I don't know if they are inherently less or more "noisy" than DC controllers). This is important when you don't want stray electrons interfering with navigation; communications; and sensitive equipment like Autopilots.

For cars, it's a different matter. The "best" answer might be the largest motor you can afford to stuff under the hood. However, when turning a propeller I would prefer to have, say, two 9" motors than one 15" motor driving the propeller shaft. That way, if something fails in one power train you still have lots of redundancy.

BUT - if severe arcing is a problem at high altitude then this would be a poor choice.


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## Automcdonough (Sep 1, 2010)

if any motor was prone to being more lightweight it certainly would not be DC, i'd think ac induction or PMDC. Also DC series is not the most efficient option.
Given the nature of redundancy, no matter which motor is chosen there would be a backup inverter.
The AC inverters are more expensive, but when it comes to size/weight not much difference.


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## Sunking (Aug 10, 2009)

PhantomPholly said:


> Too, I would have concerns about an inverter causing excessive electrical noise (although I don't know if they are inherently less or more "noisy" than DC controllers). This is important when you don't want stray electrons interfering with navigation; communications; and sensitive equipment like Autopilots.


That really comes down to the design quality. Sure a MSW type inverter, PWM, or VFD can be problematic but easily dealt with in the design. The real challenge with electric is weight, energy density and range. The controller is easy.


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## piotrsko (Dec 9, 2007)

Not sure about series DC, wouldn't be able to hear the tower, or at least when i'm test running my Kostov in the garage , the 760 comm is noisy as heck. Yup they are cheap and easy but that may not work here.

Have you had a chance to "play" with your bird to see what you can do with what? Hp tables are common as dirt for 0-320's, might even use one of the forums spreadsheets if you know the C/D.


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## PhantomPholly (Aug 20, 2008)

piotrsko said:


> Not sure about series DC, wouldn't be able to hear the tower, or at least when i'm test running my Kostov in the garage , the 760 comm is noisy as heck. Yup they are cheap and easy but that may not work here.


Well I think that answers my question - it will probably require a specially tested motor to prevent serious eletronic disruption.



> Have you had a chance to "play" with your bird to see what you can do with what? Hp tables are common as dirt for 0-320's, might even use one of the forums spreadsheets if you know the C/D.


This thread was merely "testing the waters" to see where we stand today. I absolutely know for my mission I'm not willing to give up my 1,000 mile range, and even then I'd want to know I can plug into a typical FBO 220v outlet and recharge overnight.

My IO-320 purportedly will generate 170hp @ 2700 rpm (it has high compression pistons) @ sea level on a "standard day." I don't think Atlanta ever sees those conditions. My ideal motor would generate 200 hp from around 2000rpm (at the prop, it could use gearing or belt drive) to no more than 2700rpm, allowing me to use a fixed-pitch propellor (which is lighter and cheaper) across my entire regime of flight and almost always have full power on tap.

It looks like Sikorsky has about the same idea - came across this on the MIT review site yesterday:

Sikorsky developing 180hp Helicopter electric motor


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## Sunking (Aug 10, 2009)

PhantomPholly said:


> This thread was merely "testing the waters" to see where we stand today. I absolutely know for my mission I'm not willing to give up my 1,000 mile range,


I take it from this quote you use the plane for commuting?


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## PhantomPholly (Aug 20, 2008)

Sunking said:


> I take it from this quote you use the plane for commuting?


No, I use the plane for weekend trips. Sometimes family, sometimes fun, but the one thing you cannot buy in life is time and that's what the plane does for us.

Example - we can fly to my wife's family's property in upstate NY from Atlanta in a single hop, and hours quicker than we could if traveling commercially. Using the airlines, we would travel all day - pointless for a weekend.


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## Duncan (Dec 8, 2008)

Hi Phantom

I think we are a long way from meeting your needs,
If you can get to 100mpg by improved air flow - 10 gallons = 1000 miles
avgas 6lbs/gallon - 60lbs 

Your aircraft engines peak at about 0.5 lbs/hp hour - 120 hp hours = 90 kwhours

TS cells are about 10Kg/Kwhr = 900 Kg - TOOOO MUCH!,
CALB are about the same as are Headway,
As far as I can see the best could be 5Kg/Kwhr = 450Kg
compared to the 60lbs for the avgas


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## RE Farmer (Aug 8, 2009)

Duncan said:


> Hi Phantom
> 
> I think we are a long way from meeting your needs,
> If you can get to 100mpg by improved air flow - 10 gallons = 1000 miles
> ...


As I talked about in my post #16 - the number of miles/charge is going to increase significantly due to advances in storage technology. It's already happening - check this out - 300Wh/Kg:

http://green.autoblog.com/2010/10/2...laims-new-electric-vehicle-distance-record-3/

http://www.youtube.com/watch?v=i4IXOxSxB7U

Moore's Law as it may apply to electric storage. Doubling capacity every two years means parity to petrol by 2020!


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## Automcdonough (Sep 1, 2010)

piotrsko said:


> Not sure about series DC, wouldn't be able to hear the tower, or at least when i'm test running my Kostov in the garage , the 760 comm is noisy as heck. Yup they are cheap and easy but that may not work here.


I hadn't even thought of this.. but that is huge. At this point I don't understand how you could justify a DC motor at all.


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## RE Farmer (Aug 8, 2009)

For those interested in electric flight the Aviation EAA (Experimental Aircraft Assn) is holding a contest this summer at their convention in Oshkosh, Jul 25-31. For more info:

http://www.eaa.org/news/2011/2011-02-17_efp.asp


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## karlos (Jun 30, 2008)

It may not scale up well but check this amazing flying machine!

MK-HexaKopter


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## aeroscott (Jan 5, 2008)

Automcdonough said:


> I hadn't even thought of this.. but that is huge. At this point I don't understand how you could justify a DC motor at all.


 I tend to like brushless motors for a lot of reasons too . Almost all if not all jets flew into the 70's with brushed generators (shielding and caps) . In fact the RR Dart engine(1800hp turbine) has a brushed starter that spins all the time mid 50'S built into mid 80's .


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## aeroscott (Jan 5, 2008)

karlos said:


> It may not scale up well but check this amazing flying machine!
> 
> MK-HexaKopter


 wow ! I want one big for me .


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## bga (May 25, 2009)

aeroscott said:


> wow ! I want one big for me .


Search for "Headcopter" on YouTube.

Not quite the same, but a similar feeling.


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## aeroscott (Jan 5, 2008)

I wonder how controllable it is and how much hp it takes to fly.


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