Novice Question

[Ken Leung]

Originally posted by dmellich
Being somewhat of a novice with motors/gears/transmissions I have a question. When doing the calculations to determine the correct reduction ratios to achieve a given speed, which rpm number do you start with - no load, normal load, @ max efficiency, or @ max power?

Also, is the "drill motor" everyone keeps talking about needing specs for the one that is in a small box with Bosch on it? Thanks in advance for any help.

When calculating the reduction, you should calculate the speed at free speed, because that's how fast your robot would go when driving around the field with no obstacle. Plan on losing 20% or so of free speed of your motors just because of friction inside the system.

Another way to approach the gearing is figure out how much torque you need to do certain tasks, such as going up the ramp. I mean, you can always gear however fast you want, but its useless if you don't have enough torque to go up the ramp. So, figure out the minimum torque that will get you up the ramp, and that will limit how fast you can go already. Try to gear it such that the amount of torque needed to go up the ramp is about half your stall torque.