Cutting glass

[john_hartman]

Is it even possible to cut glass on a bot?

I have 8) .125" x 7.5" x 12.5" glass rectangles which need to be cut into an "L". So I need to cut out a 3" x 6" piece from the size listed above.

If possible what type of bit, feed rates, plunge rate, depth per pass, rpm etc. work best?

If it is not possible what is the best way to cut manually? I typically cut straight and arched curves with a simple scoring wheel cutter. I figured I may be able to nibble away at it this way, but it doesn't guarantee not breaking the glass. Any thoughts would be greatly appreciated.

[mzettl]

John,

I've never cut glass with the Bot, so I really can't comment on that aspect of the question, but the basic plan of cutting glass and leaving an inside corner seems misguided to me. Even if it can be done, there would be a huge stress riser at that corner, and the chance of the glass breaking at that point would be very high. Rounding the inside corner lessens the stress riser, but does not eliminate it. I believe this is the reason that one never sees stained glass panels, etc. that have pieces with inside corners.

Would it be possible to substitute clear polycarbonate or acrylic? These would be far easier to machine without the breakage issue.

Maybe I'm misinformed, and someone with a lot more experience cutting glass can chime in.

Matt

[upsman]

John, I ask ShopBot this question about 6 months ago, They told me no, they had try it in the lab with no success. I would go with Matt, try clear polycarbonate or acrylic.

[john_hartman]

Thanks guys. I kind of determined the same thing. I just took the glass rectangles back the glass shop and had them cut it.

They drill a hole at the intersection then use a glass cutting blade to cut/remove a blades width of glass to be able to break the two sections cleanly.

[2talltary]

Polycarbonate is the better of the two. Acrylic tends to be brittle and not machine well. I usually make windows with polycarbonate and they come out great. It is also a very strong and durable material. Great place I get my polycarbonate from is http://hightechplastics.com/