Re: [CAD_CAM_EDM_DRO] Re: Adding inertia to an axis

mariss92705 wrote:

> Peter,
>
> Do not add inertia! Step motors already have a miserable torque to
> inertia ratio, adding more will simply degrade your aceleration and
> perhaps make the motor unable to move at low speeds without error if
> it is being driven with a full or half step drive.
>
> It serves no purpose.

Actually, there are special cases where it can help, but in the normal
case, you are absolutely right. The special case is where mechanical
springiness in some part of the machine (stretchable belts, bendable
gantries, torsion spring of long leadscrews, etc.) causes a strong
resonance, generally regardless of the step rate. In some narrow
cases, adding mass at the motor may reduce the resonance in some
band of interest. But, in general, it will make the system MORE
resonant. An energy absorbing damper is what is really needed.

Jon