Cutting glass

[magic]

Does anyone know how to cut 1/8 thick glass?

I want to cut a trapezoid or a square - then snap the excess material away manually, so I am left with a simple shape that has either an obtuse, square or acute angle (as opposed to an oval, French curve or other difficult shape to work with).

Is there an attachment I can buy, or make for my Alpha?

[scottcox]

This thread talks about a spring loaded diamond drag tip. Think that may work?


http://www.talkshopbot.com/forum/messages/312/30430.html

[magic]

I saw that a while back, but while reading the directions for the hand held cutters they say it's important to have the wheel turn smoothly and to not run the wheel in the same place twice because the rough edges will ruin the edge.... so I'm assuming that a diamond tip does not act the same way as a small wheel does

But I admit that I don't know anything and that's why I'm asking. I saw an episode on PBS where a CNC machine cut the glass then it was automatically lifted and set aside but they didn't show the cutter. I'll call the manufacturer of the above device.

[jamesgilliam]

Magic, Having done stained glass years ago I can tell you the best way is with the cutting tool that is made for it. Most hardware stores should carry them. With it you can also do curved pieces, just be sure to dip the wheel into a little light oil before scoring the glass, it makes for a better cut. James

[magic]

Right.
I know about the oil. I know about cleaning the glass so dirt does not get in the way. I've cut glass by hand before but want to use the BOT in this case because I have 50 pieces to cut and want them all perfect.

James, looked at your site. Your shop looks clean - I tried to click the red "Click Here For Some Signs We Have Made" and it didn't open a link but I could look at a few other projects, nice.

[knight_toolworks]

I tired it with the diamond drag tip and it does not seem to cut the glass. I could not get it to snap.

[knight_toolworks]

oops my sample was tempered glass so that may not count.

[magic]

Right.
I understand there is tempered safety, general and some with a backing. I have mirror with a backing. but I appreciate that you tried.

I bought a new wheel to see if that would work, The old wheel was rusty... but I'd still like to do it on the BOT.

Auto windshield manufactures use a CNC and i don't believe they are using water or plasma, it looks like they are cutting theirs.

[knight_toolworks]

there are cnc glass cutters. but they have indexed cutting heads. thats the key use a wheel thats indexed. so it turns as needed. a fellow showed me one for about 1200.00 but the company was not shipping.

[magic]

I believe you.

, I guess i'll just do it manually but at least I can offset a pattern and double stick it to the glass.

[Gary Campbell]

magic..
Anyone with the time or money can tool up to do special purpose cutting. There are Bots out there that cut leather, vinyl and I assume many other materials that use a drag knife or wheel.

Along with specialty tool holders that apply the proper pressure to the tool, you will also need to do some programming to allow the tool to lift and rotate at the corners to not induce fractures. You might be able to manually set a spring loaded cutter to cut multiples with one single axis cut after another, changing cutter direction between axis changes.
Gary

[jamesgilliam]

Magic, Check and see if there are any stained glass shops or suppliers in your area. They also make a cutter that is self oiling that "may" be able to swivel if you don't mind making a holder for it. They also make glass saws that use replacable abrasive rods. I can't promise anything, but if you could get a couple, cut them shorter so they would not flex with movement, and be able to hold them in a collet they could prove to be a solution. The reason the shop looks clean is we had not been in it long. With the move of the shop, and living in the framed in area, it is almost like working in a storage room now. Another few months and the excess will be at home in the house, and I can finish the shop. James

[ernie_balch]

We have glass scoring machines at GE. The wheel is held in a spring loaded mount. The wheel moves across the gantry doing parallel cuts then the glass is rotated 90 degrees and the rest of the cuts are made.
In the case of curved cuts the wheel is motorized and is steered along the curve. For 1.1 mm glass the scribe depth is about 6 microns.
It is critical to keep the glass and vacuum chuck very clean, small particles will stress the glass and cause problems. Oil is not used.
When we laser scribe glass we cut about 200 um deep.
ernie

[magic]

Thank you