Re: [CAD_CAM_EDM_DRO] PIC DRO stupid question #3

I suspect that the most difficult thing here would be finding a suitable
film which wouldn't 'tear' and so give ragged edges to the lines. Perhaps
silver plating like on a mirror? In producing fine scales on steel, this
technique is used to scratch the lines through a wax resist prior to acid
etching. Obviously in this case, the wax is a soft pliable material which
will give a clean edge but it would be no use to us for a practical scale.
The other likely problem I can forsee is the difficulty of maintaining the
correct width of line for the whole scale if it is of sufficient length as,
if we are scratching at a hrd substance, there will be tool end wear which,
if the tool isn't exactly parallel sided, will change its width gradually.

Ian

--
Ian W. Wright
Sheffield UK

----- Original Message -----
From: <ptengin@...>
To: <CAD_CAM_EDM_DRO@egroups.com>
Sent: 08 April 2000 00:19
> Let me ask this risking flames and all. If somebody has access to an
> accurate mill, could we not "engrave" a glass scale by dragging a stylus
> through a preapplied film? Many industrial machine are accurate to 50
> millionths. If we could scribe a scale to 1000 lpi, then you could get
4000
> ppi? The stylus would need to be about .0005 to .0008 inches wide. A
common
> needle?
>