Re: [CAD_CAM_EDM_DRO] Re: Casting clearance

Ron Ginger wrote:

> This talk of casting picking up small imperfections reminds me of a
> demo
> at EASTEC. There is a company that sells an epoxy resin for the
> purpose
> of picking up detail- for example if you need to measure an internal
> thread you cast in a lump of this stuff, when it cures you unscrew it
> and measure the casting.
>
> To prove the level of detail they could pickup they had a nice crisp
> new
> One Dollar bill from which they had pulled a casting that showed the
> ink
> thickness- you could clearly see the entire printing of the dollar.

This really isn't the ink thickness. US currency is printed by the
Intaglio method, and
it leaves a 'crimp' in the vellum (the notes aren't 'paper', either).
The ink is truly
'inside' the vellum, not on the surface. But, the impression left by
the intaglio
plates can be picked up. That is a fine casting material to pick that
up, it is not
much of an impression for most of the printing on the notes.

Jon