Motor Thurst

[AzViper]

New to the forums but not new to R/C.

I am gathering info. to build a quad. Watched many videos and have a good understanding of the gear needed with the exception of motors. It's my understanding the quad should have at least twice the total thrust to the weight of the quad. How does one arrive at the total thrust when many of the motor's I have seen do not list it in the spec's? Also the pitch and size of prop would have to factor into arriving at the total thrust output.

Also does a larger prop help to combat the noise?

 

[Mike]

Hobby King and other suppliers will show you a lot of prop test data for motors that shows you the thrust they saw based on a combination of things - motor/props/battery. Not all of their motors (or other sites' motors) are advertised this data though. That's why it's sometimes best to look at other successful builds to see what others are doing. Then there is ecalc, but it's tough to use confidently.

http://www.ecalc.ch/xcoptercalc.php?ecalc&lang=en

Larger props are theoretically going to give you a quieter copter, but in my experience, it's not enough to make it matter. Plus you'll have trade offs, like less responsiveness.... but if you're going for a more stable flight, larger props, lower kv motors, more cells in your battery is the way to go. When choosing prop size, other characteristics you're looking for in your flight would normally matter way more than noise - again, because the difference in noise is not so much so that it's worth changing your entire flight just to drop a few decibels.