Problem with brushless power system for ES

[detach8]

Hi guys

Hope somebody can help me here

I bought a 3550kV motor from Jet along with an 18A ESC (sadly I burnt the ESC today on its first flight, but that's a different story...)

http://www.jethobby.com.sg/cgi-bin/ezsite/prod/manager.cgi?action=show&pid=936&cid=52&idx=1

Then I used the stock 12T GWS pinion (2.3mm bore) and the stock gearing. I run 2S lipo, 1200mAh.

My ES flew like crap today. It was lacking power and flew very slow... so slow I can't even do loops with a 1047 prop. Some experts suggested it was gearing, some also suggested a change of prop.

I would like to hear some opinions and if there's anybody using the same brushless setup, and what I should change or upgrade to get my ES to fly.

Actually all I was trying to achieve is to go 2S brushless for longer flight time and slightly more power, but it all seemed to fail.

Thanks!

[Suf]

Think you change to a smaller prop cuz you lack the juice to max it out. I've been using gws brushless 15T with gws 15A esc and 2s800mah. Flying the ES on a 8040 prop for the past 2 mths practising simple loops, hammers and short inverted flights. Average flight time of 10-15 min. Dunno why many are shocked that 8040 can produce enough trhust for ES but it works fine for me. Furthermore with my power config, the 15T motor only accepts up to 8043 if not 100% will burn.

[skyblueblue]

ur 15T is how many KV ?

[detach8]

Think you change to a smaller prop cuz you lack the juice to max it out. I've been using gws brushless 15T with gws 15A esc and 2s800mah. Flying the ES on a 8040 prop for the past 2 mths practising simple loops, hammers and short inverted flights. Average flight time of 10-15 min. Dunno why many are shocked that 8040 can produce enough trhust for ES but it works fine for me. Furthermore with my power config, the 15T motor only accepts up to 8043 if not 100% will burn.

well first looking at the 15T pinion, it wont fit.. quite some mods have to be done
then also, the motor's not hot at all, means actually my big prop is still too gentle on my motor
argh

[Suf]

ur 15T is how many KV ?

arnd 2160kv

[Suf]

well first looking at the 15T pinion, it wont fit.. quite some mods have to be done
then also, the motor's not hot at all, means actually my big prop is still too gentle on my motor
argh

In that case, change to a bigger size prop preferably with a higher pitch, I'm looking at prolly as big as a 1147. Bigger size prop usually means more thrust
and thus airspeed size it screws the plane forward thru air a longer distance as opposed to a smaller sized/pitched prop. Of cuz, drawback of using a bigger prop is higher amp draw. It's better if you check ur motor specs. I swear by gws brushless cuz all the specs are clearly stated in black n white so usually one will get an appropriate esc/lipo/motor/prop size config. The only thng you need to trial and error is how much thrust your plane needs in order to fly. To me, motor thrust is akin to a jet plane's "max take-off weight" or MTOW. Hope this helps and good luck.

[detach8]

yea but weird stuff is the brushed motor actually performs better which makes me really wonder what is wrong!

[Suf]

Sorry i don't get you when you said the brushed motor performs better? How so?

[detach8]

my es couldn't even do a loop.. it just stalls when i pull back on the elevator... the airspeed is so slow.. and i fly at 100% throttle all the way... and all i could do was turns.. even then my turns lost altitiude.. if i pull back on elevator too much, my turns will stall

so i attempted a roll, and flew inverted. with max up elevator the plane just couldnt hold and i crashed my es into a puddle of water, i burnt my ESC so i put back the orig brushed motor...

and wtf i was flying like mad.. loops, rolls, inverted... it was just much more powerful

[skyblueblue]

arnd 2160kv

hmmm.... maybe a lower KV is the way to go.

[Suf]

my es couldn't even do a loop.. it just stalls when i pull back on the elevator... the airspeed is so slow.. and i fly at 100% throttle all the way... and all i could do was turns.. even then my turns lost altitiude.. if i pull back on elevator too much, my turns will stall

so i attempted a roll, and flew inverted. with max up elevator the plane just couldnt hold and i crashed my es into a puddle of water, i burnt my ESC so i put back the orig brushed motor...

and wtf i was flying like mad.. loops, rolls, inverted... it was just much more powerful

Did you set your EPA to max? Just make sure ur servo throws are to the max.
My EPA is always at 140% (full) but only for elevators.

[detach8]

there's nothing wrong with my control surfaces.. the power system was too slow.. my dual rates are already at 120.

[Suf]

hmmm.... maybe a lower KV is the way to go.

Yup true. Lower kv motors accepts bigger props cuz they provide more power as the manual suggests. Dats y they r typically more ex. My 15T is the cheapest of the series but with the highest kv. I always analogise that high kv motor is like a 2 wheel drive whereas lower kv is like a 4 wheel drive. Higher rpm but less powerful and hence accepts smaller load (high kv), lower rpm but more powerful and hence accepts bigger load (low kv). I'm def sticking to my 15T cuz it provides enough thrust for my ES to perform simple aerobatics and also cuz it's comparatively cheap at 27 bucks.

[Raven]

Hey D,

At 3550kV you may wanna try a 7x 6 or a 8x4.7.
Your setup no torque lah.
10x4.7 on a 3550kV is a lucky you nv burn your motor.
My setup only 9x4.7 on a 1280kv.


Cheers
Tak

[detach8]

huh but mine is geard with the stock 350 motor gearing...