Electric IMAC Plane poll?

[Bam Bam]

	Quote: Originally Posted by sideways
	Well i have already ordered a 2m electric pattern plane, so i can see it happening in the near future for me. My Imac Plane will soon be the only combustion powered plane i own. (Anyone want to buy a YS160 powered Cyclone, ha ha) There's a few people flying electric in pattern now. It's alot easier to justify electric over glow, in fact i'm certain glow will fade over the next couple of years in everything up to 2m. The big cost, like always, is setup. Once you're setup the price difference on a 2m size plane and under isn' t that much difference really. And electric is alot better on equipment and airframes. Besides if it was all about saving money i'd sell my planes and take up jogging. Gas is obviously a little harder to justify being cheaper to run, but battery prices are getting better and better. Hobby City have some Zippy-H batteries that alot of people are getting good results from. The only issue is that you need a generator to charge the batteries at most places........so you still have noise.....and you still burn gas. It will happen......It's just when Apparently the hardest thing to get use to is the lack of noise......try flying with ear-muffs on.

I'm used to it.... i am hearing imaired. you have to get used to things like landing without being able to hear the engine, somtimes depending on wind and such, it can be tricky judging weather your carring to much speed or not. it was had with my comp arf, as idle was really slow on take off, then come landing time idle is too hi. some people said to me "cant ya hear the engine... it's coming in real hot bro!" and i'm like "uh, nuh-uh"

[Neil4]

I think it would be cool to have an electric IMAC airplane but as people already said the li-pos kill the cost. Especially is you are flying in competition, you would need multiple batteries because you won't have enough time in between rounds to fully chrage your batteries.

I think in the near future it will be a more cost effective option but for now with gas only $1.60 and many gas engines out there that are fairly cheap and that run good, you will not see electric on the competition circuit for bit.

Neil

[RustyTumbles]

A high capacity A123 (LiFe) battery setup would be the go, as the cells can deliver the current and you can fast charge them as well.

[ou7475]

Except you have 3.3 vs 4.2 or under load i.e how many amps you are drawing you have around 3.5 vs 2.6 so you have to add cells in A123 do get the same voltage. In GS you would have to run about 16 A123 vs 12 Lipo to get around same voltage. So now you are adding quite a bit of weight but a 85-100 cc plane might handle it . The other thing about say a 5000mah pac Lipo is you have to land with around 80% left to matain a good working lipo so 4000mah with A123 you can use 2300 2p so 4600 and use all of it 4600. I flew a EF 50cc 300 Electric in Imac last year did well in my region. I had to land and change batteries in between.

Hacker A60 16L
CC hv 110
Apc 24*12 E
FP 4500 30 c 6s2p

Todd

[sun.flyer]

	Quote: Originally Posted by RustyTumbles
	A high capacity A123 (LiFe) battery setup would be the go, as the cells can deliver the current and you can fast charge them as well.

To heavy!! I ran a 14s2p 4600mah setup in one of my 50cc airplane last year and it flew like a hog and flight times were very low.

Tim

[rmarsden]

At our field, Silent electric Flyers San Diego, we fly only electric planes. For the third year now, we have monthly EMAC contests, flying the normal dual sequence IMAC pattern in Basic, Sportsman, and Intermediate classes. Most of the planes have no problem flying the sequence twice - we have planes up to 35% scale flying in the EMACs. Since it takes only 1.5 hours to fully recharge a battery pack, if you have two chargers, there is no problem using the same batteries twice during the day. Most of us have multiple sets of packs anyway for practice days. I have four sets of 10S packs and often run through them all and recharge them in a single day of flying. Rather than use a generator, I have a 200 A-Hr deep cycle battery that I charge at home using a normal battery charger before coming to the field. This keeps me flying all day long. If I share the monster battery with other guys needing a charge, I recharge it at the field using jumper cables to the main battery in the car - so never a need for a generator at our field. Note the 200 A-Hr batt weighs 120 lbs so it is a near permanent fixture in the back of my SUV.

The future of GS electrics depends on the energy density (energy/weight) of the batteries. This number has been climbing rapidly over the last few years - even the F5B planes are running LiPos now. A123 looked promising but the energy density shows no signs of improving in the near term. LiPos up to 2200 mAHr with 5C charge rates are now appearing so soon the rapid charge advantage of A123 will be gone and it will all come down to energy density increase to reduce overall battery weight while also reducing the internal resistance of the batteries to reduce self-heating and improve efficiency.

Fortunately motor/prop/esc systems are already at 95% efficiency when a good geared brushless motor is matched with a prop of the appropriate pitch and diameter. A couple of the 30-35% planes at our field run 30x20 props since the high pitch gives a much better match to the motor's properties. These high pitch props have a nice distinctive 'growl' and are easily heard anywhere in the IMAC pattern. So the complaint about not being able to hear the plane is gone - these big electrics are not much more quiet than a 100cc gas engine on cans.

At the cuurent rate of LiPo development, in about 3 years, there will be 40% electric powered IMAC planes with the same or better performance as a 150-170cc gas powered planes. The entry cost will be higher but the long term cost will be similar when reduced wear and tear is included.

I fly both electric and gas: electric up to 2 meters and gas for 35 and 40% planes. I won't miss flipping that 32 inch prop when I can replace the 150 with a nice electric power system that gives me the same power.

[Royster]

rmarsden - Thanks for the info on your club and how electrics have impactedoyur flying

Would love to hear more and if you could post up some pics of the EMAC planes as well

[gdryer]

As I previously mentioned, I am planning on flying in the Basic Category this year using my Hangar-9 Sukhoi. I run 4 6s-4000 mah Zippy battteries (12Sx2P). The plane weighs 24 lbs 6 oz with the batteries installed. In IMAC practice I am using only about 2000 mah of the 4000 mah available. These batteries are only $75.00 US each so I bought three sets (12).

I charge using A Hyperion 1210 and and 610 Duo charger connected to two deep cycle RV batteries. I charge all 4 batteries simultaneously. It usually takes about 40 minutes to replace the 2000 mah.

My limiting factor is that I can only get about 6 charges out of my deep cycle batteries. This is fine for a single day but I really need a small generator.

[sweetpea]

And then you need gas/oil to run the generator. So you are back to square one.

[lazyboyflyer]

	Quote: Originally Posted by sweetpea
	And then you need gas/oil to run the generator. So you are back to square one.

You miss the point, Major Pee

[sweetpea]

Depends.......the point of electric is for a few things

1. quick response
2. no gas mess
3. lower sound footprint
4. better for enviornment (if you are into that Al Gore line of thinking)

So.....
1. I've got nothing, electric response is faster and you can run the prop backward or slow for better braking on downlines (but in IMAC I think this should be against the rules as full scale cannot do it).

2. Yep no mess, but a gas generator requires gas and oil so there is some mess there, though probably less

3. Lower sound until there are 15+ generators running. And not everyone can afford the small , powerful quiet ones. Generators run 100% of the time so they have a constant footprint all day long.

4. better for environment I disagree with. First you have to dispose of the batts at some time. Next to charge them requires electricity. How is electricity made? Usually through Nuke, coal, dams or in the case I was stating a gas powered generator that runs all day with its exhaust spewing into the sky. And like its been said, using your car battery isn't a good idea as you'll be asking for a jump later in the day most likely.

I got no problem with folks that run electric and hopefully the price continues to drop. I just prefer gasoline powered planes.

[lazyboyflyer]

You have NO clue, 1) prop backward? 2) you don't need a generator 3) a complete exaggeration, gees! 4) environmental disaster, your laying it on thick. You don't know what your talking about.

[1bwana1]

Recent developments have the potential to change electric flight in the next few years. If the new Lithium Nano-Silicon technology works out we will get 10 times the flight time for the same weight, or 5 times for half the weight. This could mean that electrics will be lighter, fly longer, with more power than gas. No idea on cost or time frame yet, but use in cars should bring the costs down. Maybe some of Obama's billions will go into this research.

Some interesting reading.

http://gas2.org/2008/11/25/silicon-c...more-capacity/

http://gm-volt.com/2007/12/21/gm-vol...-breakthrough/

[fish2keel]

Im flying imac this year with an electric. Although its not that big its a 89" slick from 3dhs.

Next year ill be flying probably a carden or maybe something else. if I can afford it I may go electric because I love giant electrics but im not sure. A nice comp arf with a big neu I believe is in need or a big reaper in a carden I tihnk thatll do just fine.

I voted yes

[rmarsden]

	Quote: Originally Posted by Royster
	rmarsden - Thanks for the info on your club and how electrics have impactedoyur flying Would love to hear more and if you could post up some pics of the EMAC planes as well

For a quick look at a few of the planes look at our club January newletter

http://sefsd.org/newsletters/2009/0901.pdf

The planes held by Bruce Brown, Randy Marsden, and Steve Dente are all EMAC planes (Columbo Anderson Epsilon, Extreme Flight 74 in. Yak-54, CA Passport, respectively). Also second from the right is Josh Young (aka BoneDoc) who is visiting San Diego for a few months and brought along an 89 inch 3D Hobby Shop Slick 540 that we hope he will fly in EMAC while he is in town. All of these planes are powered by geared Neu motors . We have our next EMAC on Feb. 28 so I'll grab some pictures and post them here. FG covered the EMAC the first year, 2007, and posted quite a few pics of that if you look back in the archives and search under EMAC. Also, EMAC results are often posted her eon FG. For example look at

http://www.flyinggiants.com/forums/f...2-23-08-a.html

This was the first contest of the 2008 season. There are some pics of various planes, etc. If you've been to TAS, you may recognize several pilots who also EMAC.