When I solder, I'm usually pretty liberal about using flux. Not crazy with it, but not too sparing either. I've had joints that were not shiny and were not cold joints. I think that this is caused by not using enough flux, as when you happen to have to re-solder something. Flux serves to help the solder flow and it removes the impurities from the solder joint. I also typically use silver solder intended for electronics. It adds very little resistance and is VERY strong.

Well, I got my Feigao 7XL in today. It's a pretty hefty piece of motor weighing in at just over 13oz. There were a couple of things that really reflected the motor's price point. The first was that the kv rating of the motor was written on a label in marker. Other than the kv rating and the size of the motor, there's really no way to tell what it is. I hope I got what I ordered. The second was the lack of a flat machined into the shaft to accomodate the set screw of the pinion. Is this normal or did I get the wrong motor?

As for the Neu debate, I'm going with the 1515 1Y. It's just plain more efficient and the kv rating will put me in the range of 33,000 rpms. To tell the truth, if they had a 1515 with a 2400kv rating, I'd probably go with that, but I think the next jump is to the 2700kv motor and the current draw @ 10v (I think that's what the number meant) almost doubles from the 2200kv motor.

I just hope that Castle doesn't sit on the firmware revision too long. Aside from the fact that extreme cogging can be a PITA, it could also be very embarassing.