RE: Brushless motor suggestion for 5 lbs weapon on battlebot
Your not going to like the results, but I could have told you that right away. If you want to spin up your weapon that fast you need a huge motor. 8600 watts huge. I don't think you'll find an 11.5 horsepower out runner anywhere, let alone stay in your weight class with the batteries it will need or afford it.
I made a spreadsheet so that you could mess around with dimensions, rpm, time to get up to speed, etc. You can download it [link=http://cid-4a947c0fd105ba34.skydrive.live.com/self.aspx/Public/Spinner%20Motor.xls]here.[/link] I left out the inertia of the motor, shaft, and drivetrain as the shaft and motor are negligible and I assumed you are going to use a lightweight belt drive. I'm 99% sure my math is correct but if someone could check it that would be fantastic. I haven't done off center moment of inertia calculations in awhile.
Whats the weight class? Right now you have enough theoretical power to send a 200 pound bot flying 55 feet in the air.