Anybody actually fly with two 450 sized batteries?

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I built my first 425 a while back and tried to fly it on two 2200mAh 3S in series and it was hell on the batteries. At the time, I attributed it to the quality of the batteries I was using (E-Flite 20C I got with my Blade 400). I quit flying it as a 425 and stretched it to 500 on larger 6S batteries.

I recently picked up another 425 and gave it a flight on my Turnigy 2200mAh 40C batteries and after just a short dial in flight, the 40C batteries were unacceptably warm.

This prompts the question... Does anybody actually fly the 425 on 450 sized packs? What power system are you running? What head speed do you run? What kind of flight times are you getting?

The power system on the first 425 was Align 500L 1600kv motor and 75A ESC. The new 425 is TonicX Z15 1620kv motor. Both times gearing was 13T pinion, 50T front main, 19T one way, 61T rear main. I don't think I am running head speed all that high. The 425 manual calls for a head speed of at least 2600 RPMs for the standard tail blades. The head speed calculator suggests my head speed would be 2733. I know I run my Trex 500 higher than that.

[KRYPTO316]

I tried the 2200 bats on the stock set up with the gaui 1400kv motor and would only get about 3.5min fights. So i bought a hyperion 6s 2600 pack and i am getting 5min now sport flying a few flips,rolls and some inverted hovering up high.

[jczankl]

Hello Ivan,

I still run my 425 on 2 3s packs getting 3-3.5min Turning about 2900 on the RotorHead

GAUI 1400KV Motor (Scorpion)
14T Pinion
19T One Way
50T Front Drive Gear
61T Main Gear

Works great.

Regards
JC

[jason mc]

Yes I fly 2-2200ma 3s packs in my 425 (blue lipo 25c) No I dont really care for them either. There good for my 450. but in the 425 I feel they get a little too warm for my liking and only get a 3:30 flight time ( which is to be expected on 2200ma packs) I also use 2-2200ma 3s sky lipo packs 40c and Im happy with those so far...they stay cooler than the 25c and have a ton of power on tap. same flight time as the blues. I just ordered 2-3300 3s 40c sky lipo to try out, I am wanting to see if I can get a little longer flight time...

[mightymouse]

Yep I fly with the 2200's X2 turnigys im gettin 4 and 5 mins putting 1800 mahs back in on recharge- flew two sets today and with the X5 canopy my lipos feel alittle colder I have alittle more air moving around them.--my 425 is my hotrod and my 550 hurricane is my caddie!!

[sp00fman]

Does the headspeed of 425mm blades affect the flight time/amp-draw a lot?
I geared it down to 2350 rpm, but if 2500+rpm wont pop my 20C 450size lipo's open i will like it better.

total; weight without lipo's is 1580gram. Is that on par with others?

[Jerrymac]

IMO, head speed does affect flight times quite a bit. My 425 runs a head speed of around 2900 to 3000. I get 4:00 flights with 6s 2650 30c batteries and put back in 80%. My medium-boomed HeadHunter framed Hurri with 500mm blades runs a head speed of around 2300 to 2400 and with the same 6s 2650's I get 5:00 flights and only put back 60% to 70% of charge in the batteries.

Total weight of my newest 425 build is 1630g without battery. That is with full size cyclic and tail servos, large JR servo wheels, spartan DS760 gyro, Align 75A esc, HobbyWing 5A ubec, 430mm blades, CNC swash plate guide, and Gaui FG canopy.

My other 425 is likely a little bit heavier as it also has a full Gaui CNC head assembly.