Guys this is my first post here so I don't know whether this site will fit to answer my question or if it do either it us right place or not so please ignore or help in either conditions

So my question is that:

I am was going to make a quad copter so I thought I'll buy a RC copter from store and then solder 3 another motors to same point where the motor that comes with rc copter is solded and add another battery to supply more power

So I was wondering that will this idea work if not any other suggestions will be appreciated