Trex 450 on 4s, more power, cooler running.

[Dean in Milwaukee]

A few years ago I recieved on of the T-rex 450x's for my birthday, and proceeded to build it and fly it with a futaba 401 and a Justgofly.com th450 with 12t pinion and the cheapy 3s2000's I had back then. While the heli flew well, flight times weren't good as the batteries struggled with the load and the motor got hotter than I expected. Trying a 11t pinion helped the flight times and heat issues, but power was down. The solution was dropping to a 10t pinion and going up to 4 cells. I now have a solid 2400 rpm bog resistant headspeed and the motor comes down nearly cool. The big bonus is flight time. I'm getting 12 minutes of sport flying on 4s2000's. That means an average flight current of only 10 amps. I painted it neon green to help see it better and that did help. Here's some pics: Green 4s Trex.

Dean in Milwaukee

[solentlife]

I know this is an old thread .... but cannot resist getting it up again.

Do you not find a CoG problem with a 4S pack up there ? I have various 3S packs all for 450 and they all have different weights and alter CoG. I notice that if I use my Turnigy standard blue 3S 2100's ... they make my 450 move forward because they are heavier than my GE power 2280 3S packs ...

[Dean in Milwaukee]

Originally Posted by solentlife

I know this is an old thread .... but cannot resist getting it up again.

Do you not find a CoG problem with a 4S pack up there ? I have various 3S packs all for 450 and they all have different weights and alter CoG. I notice that if I use my Turnigy standard blue 3S 2100's ... they make my 450 move forward because they are heavier than my GE power 2280 3S packs ...

Yes i noticed a difference, but it was small and easly trimmed out with just a click or two if I recall correctly. I am not a hardcore 3d flyer, and have noticed that for sport flying being a tiny bit nose heavy seems to make the heli fly smoother and more predictably. The gains in flight time and bog resistance make this mod very nice for us sport flyers.

For 3d pilots, you could just use a smaller 4 cell pack of the same weight as your 3s pack, a 4s 1600 pack being about the same weight as a 3s2100 pack. Flight time and bog resistance would both be better than what your used to. The key here though is the smaller pinion. Without it 4s is not a good option.

Dean in Milwaukee