[gdb]

What is more important Inerta or Torque when trying to size stepper motors.

Glen

[Al_The_Man]

They both should factor in.
See this previous post.
http://cnczone.com/forums/showthread...=inertia+ratio
Al.

[gdb]

Thank you, you have been a big help.

Glen

[NC Cams]

Inertia is defined as the abilty of a body at rest or in motion to stay in that state until some external force acts upon it.

Inertia is a function of BOTH the mass of the body and the location of where the mass is centered.

Take two flywheels that weigh exactly the same weigh, but one is small in diameter and long in lenth axially (sort of like a servo motor armature) versus one that is short in length but large in diameter (pancake motor armature). In this example, the pancake would PROBABLY have more inertia than the servo shaped flywheel.

Hence, for EXACT same input torque (twisting force) applied to a given flywheel, the theoretical "pancake" flywheel will accelerate or decelerate slower than the "servo" flywheel due to the lower inertia assumption.

This is a quick and dirty explanation but it should give a reasonable understanging about what's going on.