View Single Post
Old 05-29-2012, 07:21 AM
  #310  
ramboman
Member
 
Join Date: Mar 2006
Location: Waterloo, Belgium
Posts: 121
Default

Originally Posted by kyleservicetech View Post
What's the wingspan, wing area, and weight without motor/ESC/battery?

One of those programs such as www.motocalc.com will be of considerable assistance in your power selection.

Running about 8 pounds, a good performing model will work well at 150 watts per pound of airplane, so that would be around 1200 watts or so. A very large number of electric motors of that power range are available. Some good, some bad, some just crap. (The Scorpion motors have a good record)

IMHO, when power levels of 1000 watts or higher are involved, it's wise to use quality name brand motors and ESC's. I'm known for liking the Hacker motors, and a Hacker A50-16S motor with a 6S LiPo of around 4000-5000 Mah will work well. The Castle Creations ICE series of ESC's are also good, they also have the switching power supply uBEC's (Battery Elimination Circuit) The ICE ESC's also have the ability to record voltage/current/watts/RPM/temperature and a few other things during flight. You need the CC programmer to download this information.

I've got three A50 motors. One is the A50-16S motor which is installed in a Showtime 50, with a 7S2P A123 battery pack, and a 16X12 APC-E prop. That combination hauls the 8 pound model straight up, out of sight. (The 7S2P A123 pack is similar in power performance to a 6S 4200 Mah LiPo battery)

Other options would be a Hacker A50-12S motor running on a 5000 Mah 5 cell LiPo. This A50-12S setup will turn a 14X10 APC-E prop at about 8000 RPM, pulling 65 Amps and 1100 Watts out of a good quality 5 cell LiPo battery. (I've got two of these A50-12S motors. Flawless over 5 years of flying with them.)

Take a look:
Thread on 70 size glow engine conversion to electric
http://www.wattflyer.com/forums/showthread.php?t=45222

Hacker 6S2P A123 powered Models
http://www.wattflyer.com/forums/showthread.php?t=44686

The bottom line, a good quality electric power system, properly matched to the propeller size, and LiPo battery can easily match the model performance using a similar size glow engine. The glow engine can fly longer on a tank though. A good electric setup will fly about 6 minutes on a battery charge, with a few minutes reserve power.

Different simulators, including motocalc, give very different results...
I have very good experience with Castle in various configurations:
* Torque 4014 with 6s2p a123 and 15*8 for .60
* Scorpion 5525/225 with 12s2p a123 and 18*12 for .160
* Hacker A60-6XS with 7s2p a123 and 19*10 for .110
I needed a smaller pack fo my TaylorCraft 20cc...
ramboman is offline  
 
Page generated in 0.04927 seconds with 8 queries