CAD CAM EDM DRO - Yahoo Group Archive

Re: [CAD_CAM_EDM_DRO] linear scales as encoders?

Posted by Jon Elson
on 2000-07-07 23:31:24 UTC
fogassa@... wrote:

> Question:I'm getting exited about servo drivers(99 bucks sounds
> good)What if one uses a linear scale as a encoder? instead of having
> the encoder right at the motor shaft?I think it would give a better
> positioning of the table itself instead of the error associated with
> lead accuracy,backlash,elastic deformation, or belt drive error.

Well, I can tell you that MY servo amps could be made stable with such a
setup.
I don't know about the $99 jobs, though. With that much stuff between
the
motor and the encoder, you would need some serious loop compensation on
the velocity control loop to assure stability.

Now, my servo amps are full analog servos, so they need a DC tach and a
DAC in the computer to send a +- 10 V velocity command to the amp.
I'm working on a way to have cheaper DACs and encoder counters for
EMC than the Servo-to-Go card.

Jon

Discussion Thread

Jon Elson 2000-07-07 23:31:24 UTC Re: [CAD_CAM_EDM_DRO] linear scales as encoders?