Re: [CAD_CAM_EDM_DRO] Re: Digitizers, Renishaw

Roman Black wrote:

>
> Ok, are you saying the Renishaw device uses simple
> make/break electrical contacts??

I wasn't the guy that took one apart, but that is clearly
what he described.

> Second, .0002" is big by opto standards.
> The simple laser unit in any cheap CD player
> focuses MANY TIMES smaller than that, and
> has a tiny chip attached to it that gives
> amplification and a dc voltage output which
> even has a little trimpot to adjust. I have
> to fix these mongrels sometimes! ;o)
>
> One of these would detect your 0.0002 easily,
> even after the reduction from leverage
> from pointer length to mount width.

How would you make such an optical sensor? Or, are
you suggesting that the sensor assembly from a CD
player can be directly installed in an optical probe?
The CD sensors, I believe, rely on the continuous motion
of the little holes past the sensing head to develop the
correct tracking signals.

> But once you start getting the "mines smaller
> than yours" thing happening isn't it going
> to false trigger and stuff due to machine
> vibration??

The spindle of a machine tool should not have much vibration
when it is not running. The movement of the table should not
be able to give much vibration to the spindle.

Jon