Ok, I am confusing myself on motor selection for a small bot. Hopefully someone can set me straight.
Here are the values I'm entering into the RMF calculator
Desired Velocity: 3ft/s
Desired Acceleration: 1.5f/s2
Expected Efficiency: 65%
Incline Angle: 0
Wheel Diameter: .06m
# of Powered Wheels: 2
It tells me my RMF is 1.65, and my Rotation is 291rpm. Maybe I am using the calculator wrong, but in the Motor Characteristics section I enter 300 for RPM and play with the Torque value until I get close to my required RMF, which comes out to about .35lb-ft (67.2ozf-in according to this
). I take this to mean how much torque I need to achieve my desired acceleration.
Now here is where I get confused (or maybe I was already confused above). I go to http://www.robotshop.com/dc-motor-selection.html
and enter the same values. It tells me my torque is 2.0329ozf-in. I take this to mean how much torque I need to achieve my desired acceleration.
2.0329ozf-in is way less than 67.2ozf-in. Where am I going wrong?