Re: [CAD_CAM_EDM_DRO] A Basic Servo Question....WELL ....may be not !!!

Babar wrote:

>Hi All,
>
>Last week I came across a AC Vector Drive Inverter
>with which I operate a 5HP AC Induction motor, this
>inverter takes +/-10V signal and the Torque I got from
>the motor was excellent.
>Due to this an idea came into my mind that Why cannot
>be this Vector Drive+ Normal AC motor can be used in
>CNC machines instead of Servo Motors +Drives?
>

They can. Some larger commercial CNC machines are using motors of
this type. First, you may need fan cooling of the motor, as it may be
required
to deliver torque while the rotor is not turning fast enough for the
internal fan
to move much air. Second, a brushless permanent magnet motor will have less
inertia in the rotor, and will usually be smaller overall. You need to
add an
encoder somewhere in the system. Finally, this system may not have the
bandwidth
that is expected of a machine tool servo. It may still be fine for many
applications,
however.

> Are
>there any other issues which should be considered in
>this regard?If it can be done then it would be a very
>cheap solution.
>
>
>

Only if you have access to surplus vector drives is this going to be
a "cheap solution".

Jon