Electric Power for a 20cc Profile

[Bartman]

In another thread we're building a 20cc profile ARF from RedwingRC.com;
http://www.giantscalenews.com/threads/group-build-20cc-profile-arf-whos-in.3466/

The planes we're building were designed around the DLE 20cc with the beam mounting case. A fueled engine requires the following

• engine w/ muffler
• fuel tank
• fuel lines
• ignition system
• ignition battery (and flight battery)
• optical kill switch (for an electronic ignition engine like the DLE 20)
• throttle servo

When you start talking about electric power you can eliminate the engine, fuel tank and lines, ignition system, batteries, kill switch, and throttle servo......ALL OF IT!

But what do you need then to go flying with batteries instead of fuel?

• brushless motor
• wiring harness
• ESC (Electronic Speed Control)
• Battery (a big battery!)

The ESC will very likely have a BEC (Battery Eliminator Circuit) circuit in it which will allow it to power your receiver and servos from the big motor battery eliminating the need for what is usually called the flight pack.

I'll add everything up and post an estimate of what one system weighs vs. the other but for people that choose to go electric it's not usually to save weight. It's usually because they've had some bad experiences with fueled engines and have given up or their flying field has decided to go all electric or at least impose onerous noise restrictions. Some people just like the convenience of being able to plug in a battery and start flying immediately without the hassles of starting and tuning fueled engines.

In my case, I'm building my 20cc profile ARF with electric because I want to fly it closer to home where the field is not as noise friendly.

Regardless, let's see what everyone's doing to get their giant scale planes in the air using electric power instead of fueled power.

 

[BalsaDust]

Excited to see what your cost and up at and what kind of power you get out of it.

 

[Bartman]

well, the motor is a Turnigy L5055B-600kv
http://www.hobbyking.com/hobbyking/store/__19617__Turnigy_L5055B_600_Brushless_Outrunner_600kv.html

and the ESC is a Hobbyking 80A with BEC
http://www.hobbyking.com/hobbyking/store/__16893__Hobby_King_80A_ESC_4A_SBEC.html

and I've got at least a dozen of these batteries, they're probably a bit too big but we'll see
http://www.hobbyking.com/hobbyking/store/uh_viewItem.asp?idProduct=57378

the motor is max 1500W at 55A (you recommended about 1200W) for a 20cc slab so it should be interesting to see how it does. i was just looking at the fuselage to see about mounting everything and I think it is going to be very straightforward so no problems anticipated!

 

[BalsaDust]

More power is always better. Flew a buddies profile a while back was a 35" wingspan plane. All up weight was 16oz with the battery and he had a hacker A2020 on the nose. Same motor I have on the chubcub profile I designed that weighs 30 oz and it's not hurting at all for power so just imagine the little 16 oz plane.
Those parts all look good to me that you have picked out.

 

[Bunky.F.Knuckle]

the motor is max 1500W at 55A (you recommended about 1200W) for a 20cc slab so it should be interesting to see how it does.

My EF Laser was 1900W on 6S 4000's. It was 6# RTF. Had just less than 3:1 power to weight.

 

[49dimes]

Being the electric bug has bitten again........Have any of you tried the HK SK3 series of motors??? A bit more pricy than the NTM, Motor match and Turnigy regular series motors but they are built just like the Hackers. Don't know if the quality will be the same but looking at them looks promising. I have had to literally completely disassemble, clean, balance and lube both NTM motors I just purchased. The G32( motor match series) had no problems but like their alter ego (E-Flight power series) it lacked in power. The NTM's are very powerful and seem to have great windings and great machining but seem to lack attention to detail from assembly. I'm hoping the SK3 series will be a nice complement to a EF 64" MXS and 74" EDGE. Both EXP series planes.

 

[Alky6]

Being the electric bug has bitten again........Have any of you tried the HK SK3 series of motors??? A bit more pricy than the NTM, Motor match and Turnigy regular series motors but they are built just like the Hackers. Don't know if the quality will be the same but looking at them looks promising. I have had to literally completely disassemble, clean, balance and lube both NTM motors I just purchased. The G32( motor match series) had no problems but like their alter ego (E-Flight power series) it lacked in power. The NTM's are very powerful and seem to have great windings and great machining but seem to lack attention to detail from assembly. I'm hoping the SK3 series will be a nice complement to a EF 64" MXS and 74" EDGE. Both EXP series planes.

believe i have the .10 size sk3 motor series - will have to double check. Seems to be well built and runs well. I'll have to prove it to you later lol.

 

[pawnshopmike]

Being the electric bug has bitten again........Have any of you tried the HK SK3 series of motors??? A bit more pricy than the NTM, Motor match and Turnigy regular series motors but they are built just like the Hackers. Don't know if the quality will be the same but looking at them looks promising. I have had to literally completely disassemble, clean, balance and lube both NTM motors I just purchased. The G32( motor match series) had no problems but like their alter ego (E-Flight power series) it lacked in power. The NTM's are very powerful and seem to have great windings and great machining but seem to lack attention to detail from assembly. I'm hoping the SK3 series will be a nice complement to a EF 64" MXS and 74" EDGE. Both EXP series planes.

I bought the SK equivalent of the Hacker A40. The windings on the armature look like a baitcast fishing reel with a severe case of backlash. When I was mounting it I pulled the threads out of one of the mounting holes. Didn't even have enough force on the screw to mash the lock washer. Had to tap it out to a larger size.

As far as performance, I only have two short flights on it so far so can't really tell yet. It's strapped onto the Wild Tiger Profile that @cbarnes0061 built for me.

I won't be buying any more SK motors.

I'll stick with Hacker and Axi. Yes they cost more. And yes they are worth it! Some of my Axi motors are 10 years old and still truckin. No telling how many flights are on them because they were used when I bought them. I have a couple small Axi and Hackers I bought new in 2010 that I know have at least 300 flights on them. They have outlasted dozens of airframes.
Money well spent.

 

[Bartman]

Money well spent.

i have to agree, i bought one of those gold top/bottom crap motors for a slab foamie and it made good power for about ten flights and then was more of a battery discharge tool than an actual motor. with all of the chinese stuff, it's a crap shoot, sometimes you do ok and other times it's money down the drain. usually i look for good used motors that haven't been beat to crap before going the HK route. but if it's no flying or flying with less expensive equipment i'd always say get flying and do what you can when you can with the equipment.

 

[BalsaDust]

I have the same sk motor to go on a 40 size slab that I have a kit for. It's wound for a 6S lipo where as Mikey's is wound for 4S. The buddy I got the motor from said it makes really good power and he has another on one of his planes but I know this one had two broken bolts on the prop adapter. We will see whenever I get around to building the plane. I do know I have a little small hacker A20-20 and it is a badass little motor.