I am currently experimenting with a low cost E setup for 1/2A aerobatic use for mt 12 year old son to fly at the partk when we can't get to a big circle. The plane I'm experimenting with is a Li'l Hacker II, a 1/2A combat wing from CoreHouse. The plane is built pretty much stock, I added a 1" spacer behind the motor to get it further forward to get the CG more right. I also cut the tips off the wings to get it down to ~180 sq. inches after the first flight. I did a bit of research and bought the following to items to start with. Overall cost flying is about $35. With additional cost if you buy more batteries, charger, etc...
1400 Kv Outrunner Motor, $9:
http://www.hobbyking.com/hobbyking/store/uh_viewItem.asp?idProduct=420410A Esc, $9:
http://www.hobbyking.com/hobbyking/store/uh_viewItem.asp?idProduct=514322-Cell, 360 Mah Battery, $5:
http://www.hobbyking.com/hobbyking/store/uh_viewItem.asp?idProduct=73013 Cell, 360 Mah Battery, $7:
http://www.hobbyking.com/hobbyking/store/uh_viewItem.asp?idProduct=7302Timer is the E-Flite one for $10
Flew for the first time yesterday with a GWS 8x4.3 slow-flyer prop ($0.50).
With the 2 cell battery, perfromance was lacking, just barely enough speed to stay out on the lines and zero aerobatic potential. The AUW with this battery is 7 oz. The Li'l Hacker wingtips were cutoff to give the wing area about 180 sq. in and it perfromed a little better than stock with 220+ sq. in., but still not viable for aerobatics.
With the 3 cell battery it weighs 7.2 oz and it could loop on the downwind side, but was still pretty anemic.
The amps for the 2-cell were about 5 amps and the 3-cell was around 6 amps. I used about 60Mah per minute on the 2-cell, meaning I could fly as much as 3 minute on the 360 packs. On the 3-cell, I used about 110Mah, meaning a two minute flight is about as much as I could get.
This tells me I have a little more power available in both the motor/ESC/Battery combos if I can find the righgt prop. I am going to try a APC 6x5.5e prop next and see if it gets the pitch speed up a bit, since the 8x4.3 prop had plenty of thrust, but did not cary enough speed/energy to stay out on the lines like it should.
The general goal of my setup was to be a light as a 1/2 glow setup (6-7 oz) and have moderatley aerobatic performance. If I concede a bit of weight and go to 9 or 10 oz, then it opens up a much wider range of motor/battery combinations that will give much better performance. Using a bigger battery 450 to 800 mah, allows pulling 10+ amps from the batteries, and allows the use of a more powerful motor. You end up in the $50 to $60 range...
An Alternate Motor with similar characteristics that seems better (lighter/more power) than the one I bought is:
http://www.hobbyking.com/hobbyking/store/uh_viewItem.asp?idProduct=6547I'll try to post back with some more results when I have them...I plan to build the second plane from the double kit with few mods to lighten it up abit.
Regards,
Richard Lewis