What to do with my 3rd IRCHA 425 kit??

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I had been wanting to pick up another IRCHA 425 kit for some time. I had stretched my original 425 to 500 and had the motor / blades from it just sitting around. Well, I found a good deal on a PNP 425 which had a second unbuilt kit with it. So the question now is... should I stretch it to 550 seeing as I have a 425 and 500? I guess my main issue would be motor / battery and CG. I can't seem to get a good motor for my 500. The 500 is an odd size and the Gaui gearing favors a lower KV motor. I am also having a hard time finding an appropriate sized battery that will both fit and CG well. I fly a 3000mAh 6S on my Trex 500 (425 mm blades) but it seems like my Gaui 500 would fit / CG best with a 2650mAh 6S.

So.... what would you suggest for motor / battery for a 550 stretch? How is your CG? What kind of head speed do you run? How long are your flights?

[Jerrymac]

Ivan, I have one built with each size boom and blades.

On my 550 I use the stock Gaui 850kv motor and 2x3s 3300mah batteries in series. The problem was that it was nose heavy so I also use a 2s 2500 for the rx and have it mounted at the very back of the frame. I am thinking newer lighter batteries, or something around 3000mah would work out right. I can get 8 min flights with my set up.

With the many gearing options, you can use a motor from 850kv to around 1100kv for the 550. I run a head speed of somewhere around 1900.

The biggest problem with running 6s batts is that the frame was designed for 2x3s in series. Some people have run 6s on them, but not sure what size will fit under the canopy. I modded the front of the frame on my 425 to use 6s and it works fine.