Re: [CAD_CAM_EDM_DRO] Re: Creating long straight edges

Those levels are about the best deal around....10 arc second vial
and hand scraped base for less than $100.

If I felt the need to do an optical system I would prob put together
an autocollimator from high quality surplus lenses- like those
reconissance aircraft camera lenses so many surplus houses sell.
It takes some pretty fair lenses to do better than 10 arc seconds
though. The one advantage autocollimators have is the ability
to do integrated straightness in multiple axes at once... that
is convenient for things like v-ways.

Les

Leslie Watts
L M Watts Furniture
Tiger, Georgia USA
http://www.rabun.net/~leswatts/wattsfurniturewp.html
engineering page:
http://www.rabun.net/~leswatts/shop.html

----- Original Message -----
From: "turbulatordude" <davemucha@...>
To: <CAD_CAM_EDM_DRO@yahoogroups.com>
Sent: Sunday, July 07, 2002 8:47 AM
Subject: [CAD_CAM_EDM_DRO] Re: Creating long straight edges


> I had offered the idea of a laser in answer to just aligning the
> rails. But that was some time ago. I think it was Jon who offered
> that the laser not only diffuses over distance, but if you are using
> a pocket pointer, the beam is not parellel to the axis of the housing.
> Some even recomended rotating to remove the error.
>
> And one can use a couple photo receptors or similar (LED's even) to
> read the intensity, and with a cheap op-amp or comparator, design a
> circuit to pick up the edge of the light.
>
> That said, if you chose to try a laser you still have to move it
> along and manually raise and lower some device like a micrometer.
>
> And although it seems more fun than a level, it seems to me that it
> adds more time and complexity and does not offer a higher accuracy
> than the level.