Can I use different sized props?

[archie12345]

When I bought my props from a local RC shop for my hexacopter i got 4 x 1555 carbon fiber and 2 x 1455 carbon fiber props because the 1555 has only 4 left my motor's recommended props were 15 inches diameter, the guy told me that this would work. I am a beginner so I want to confirm if this would really work

 

[XNS]

When I bought my props from a local RC shop for my hexacopter i got 4 x 1555 carbon fiber and 2 x 1455 carbon fiber props because the 1555 has only 4 left my motor's recommended props were 15 inches diameter, the guy told me that this would work. I am a beginner so I want to confirm if this would really work

Hey Archie12345,
I would go to the motor manufactures website and look up the specs on the motors. At least for the motors I use, they always give exact info for what is recommended for their motors. This includes prop size and pitch and power requirements. I always start there for my builds (then maybe, maybe experiment later).

Regarding using two different sizes, I personally wouldn't try that on a craft I plan on keeping intact. But that is my opinion.