RC-Monster Forums - View Single Post - Torque and RPM Graph for Castle Creation products ?

VintageMA · 10.27.2008, 12:22 PM

I know this is an odd follow-up to this graph, and I understand the multiplication of the torque at the motor through the gearing to the wheels, but I have a follow-up as to how we can apply this to real setups?

Is there a way to calculate how much torque an application will need for a certain amount of acceleration or top speed? Obviously you would want to pick a motor where the torque your application needs doesn't fall off the top of the efficiency scale where it starts to drop back down from max eff%.

Also - I am confused with the oz/in ratings when comparing to servos. Picking a servo for an application we see ratings in the 125oz/in all the way up to 400oz/in. I know this already takes into account the reduction gearing in the servo and there is also much the throw of the servo compared with a spinning motor. But, when I look at that graph and see ratings for 25-30oz/in of torque for these huge motors is just seems very small in relation to a servo putting out 5-20 times more torque.

Does where I am going make sense? Can anyone help explain the relation a bit more?

	(#23)
VintageMA RC-Monster Aluminum Offline Posts: 660 Join Date: Sep 2006 Location: CT	10.27.2008, 12:22 PM I know this is an odd follow-up to this graph, and I understand the multiplication of the torque at the motor through the gearing to the wheels, but I have a follow-up as to how we can apply this to real setups? Is there a way to calculate how much torque an application will need for a certain amount of acceleration or top speed? Obviously you would want to pick a motor where the torque your application needs doesn't fall off the top of the efficiency scale where it starts to drop back down from max eff%. Also - I am confused with the oz/in ratings when comparing to servos. Picking a servo for an application we see ratings in the 125oz/in all the way up to 400oz/in. I know this already takes into account the reduction gearing in the servo and there is also much the throw of the servo compared with a spinning motor. But, when I look at that graph and see ratings for 25-30oz/in of torque for these huge motors is just seems very small in relation to a servo putting out 5-20 times more torque. Does where I am going make sense? Can anyone help explain the relation a bit more? “Everyone has a right to be stupid; some people just abuse the privilege.”