Putting a planetary gearbox on an RC plane?
 

From what I've seen just one layer of a planetary gearbox can give more than 5 times the speed of a motor, I'm thinking of using the 3D designs of a planetary gearbox and making them out of materials that can withstand heat, but are also durable. What do you think about using a lightweight planetary gearbox on a motor to give it more extra speed? Would it increase performance? Will it make weaker, more efficient motors get more performance? Will there be problems with starting?