Re: Glass cutting

On the topic of home shop CNC cutting of glass, I used to cut glass
by first using a wheel to scribe it, then chasing the crack around
with a bit of red hot nichrome wire. It only took a bit of current
to heat the wire, the heat would cause the crack to open if applied
immediately after the scribe.
It is easy to imagine using this technique with CNC. Either a head
could be made containing both the scriber and the hot wire, or after
scribing the head could be changed to a hot wire.
Tapping is used manually to enlarge the scribed line to a crack,
maybe a buzzer could be adapted for this purpose?

If you had a CO2 laser, that would be ideal for the purpose of
enlarging the crack. The 10.6 µm light is absorbed very efficiently
by common glass.

regards-
Elliot

--- In CAD_CAM_EDM_DRO@yahoogroups.com, "Tony Smith" <ajsmith@...>
wrote:

>
> > On Oct 22, 2006, at 6:38 PM, Jack Coats wrote:
> >
> > I know it is not the same thing, but has anyone tried
> > 'milling' glass, to 'mechanical etching'?
> >
> >
> >
> > It is done all the time and has been done longer than what
> > you might call "machining.". but it is called "grinding " see
> > lapidary. it does need to be cooled . Heating the glass

will

> > make things worse.
> >
> > The cnc glass cutting technique is done on VERY thin stock --

it

> > won't extrapolate to even normal thin window glass. it

isn't

> > hard to orient the cutter wheel but you need more than just a
> > scratch to break thru. Search glass breaking pliers and also
> > glass cutting. The burglar technique isn't how it is really

works .

> >
> > Silicon chips from wafers are sawed not cut by breaking

although

> > the machine described cuts glass near wafer thickness. There

is

> > an interesting technique shown where the carbide wheel axle
> > hole is cut with a spline or like an internal planetary gear
> > to put enough vibration in to run the break.
>
>
> That site was claiming to cut 6mm (1/4") glass on that machine.

Neat trick

> if it true. Or I read it wrong :)
>
> Tony
>