re:re: lighted edge finder and lasers
Posted by
Elliot Burke
on 2000-10-13 09:12:31 UTC
The idea of using a CD player head for detection of this or that has been
raised in metrology circles over the years. A CD read head is a confocal
scanning microscope, with servo control in focus and one orthogonal (pitch)
axis). Detection and control of the head position is better than 1 micron.
That being said, if you're not looking at a CD, the pitch control probably
won't do much, perhaps it could detect an edge. The focus control might
work on a diffuse surface rather than the usual specular CD surface. Their
output from machined metal surfaces might be hard to predict.
Signals are usually taken from a quadrant type detector. These might be
possible to intercept somewhere, the head is usually cabled to the rest of
the electronics.
I've never played with CD reader electronics, so don't know how hard this
would be to do.
As an edge finder, I like the kind that touches the object below an edge.
Edges are frequently bunged up, and might not represent where the edge of
the part is.
Elliot Burke
raised in metrology circles over the years. A CD read head is a confocal
scanning microscope, with servo control in focus and one orthogonal (pitch)
axis). Detection and control of the head position is better than 1 micron.
That being said, if you're not looking at a CD, the pitch control probably
won't do much, perhaps it could detect an edge. The focus control might
work on a diffuse surface rather than the usual specular CD surface. Their
output from machined metal surfaces might be hard to predict.
Signals are usually taken from a quadrant type detector. These might be
possible to intercept somewhere, the head is usually cabled to the rest of
the electronics.
I've never played with CD reader electronics, so don't know how hard this
would be to do.
As an edge finder, I like the kind that touches the object below an edge.
Edges are frequently bunged up, and might not represent where the edge of
the part is.
Elliot Burke
>Subject: Re: Lighted edge finder
>At the risk of ressurecting on old thread, just a thought; would there be
>any way of adapting the laser (and associated optics) for a cd player to
>sense edges and/or center punche/scribe lines? As I say, just a thought.
>Hugh
>At 09:18 AM 10/6/00 -0500, Joe Vicars wrote:
> I was thinking about making a LED edge finder. A peice of Drill
>Rod, a battery and an LED. The rod touches the part and the machine
>completes the circuit to light the light. Is there something I am
>missing in the construction of this item? It seems really simple.
>
>
>Welcome to CAD_CAM_EDM_DRO@...,an unmoderated list for the
>discussion of shop built systems, for CAD, CAM, EDM, and DRO.
>
>Addresses:
>Post message: CAD_CAM_EDM_DRO@egroups.com
>Subscribe: CAD_CAM_EDM_DRO-subscribe@egroups.com
>Unsubscribe: CAD_CAM_EDM_DRO-unsubscribe@egroups.com
>List owner: CAD_CAM_EDM_DRO-owner@egroups.com, wanliker@...
>Moderator: jmelson@... [Moderator]
>URL to this page: http://www.egroups.com/group/CAD_CAM_EDM_DRO
>FAQ: http://www.ktmarketing.com/faq.html
>bill,
>List Manager