Useful Formulas Spreadsheet

[Greatscott]

I'm am putting together a spreadsheet of RC formulas and I was wondering what formulas you guys routinely use and why. Currently I have a RPM-per-volt calculator for brushed motors, a calculator that figures out the final drive ratio of an Axial, and I have mashed these two together to give me the wheel RPM for an Axial running a brushed motor (motor turns vs voltage vs pinion/spur).

I am upgrading to a 45T from a 65T. Running at 7.2, a 65T motor geared @ 14/87 produces a wheel RPM of 126; a 45T motor gears the same way produces 182 RPM. (a 35T would be 235 RPM)

Anyone have RPM per volt info for brushless motors? Any other RC formulas you can throw at me?

Have a spreadsheet already running? Lets get them together!

Thanks.

[Harley]

Originally Posted by Greatscott

Anyone have RPM per volt info for brushless motors? Any other RC formulas you can throw at me?

Have a spreadsheet already running? Lets get them together!

Thanks.

I believe a pretty good estimation for brushless motors is 1 rpm/kv/volt

So a 1000kv brushless motor will be spinning 7200rpm at 7.2volts.