ORIGINAL: bruce88123
Solder can actually generate a vibration fracture point. This is due to the wire becoming stiff where the solder is. A crimped connection does not have this problem. This is one of the reasons they mostly crimp on full scale planes except on circuit boards and the like where the connections are supported. A little bit of heat shrink helps IF you can get it into the right place.
Interesting...
Though I would assume that the original poster is working with smaller electric planes where vibration is not going to be an issue anyway.