Scratching glass

[curtiss]

A bit of a snow day today. I tried "scratching some glass" with some double sided tape and a few mouse pads.

Turned out pretty well actually, and did not break anything. The pads absorb the pressure from the bit and there is not much lateral pressure of course.

I zeroed to the glass as normal and started with a .02 cutting depth. This eventually became .06 to generate enough pressure for the desired result.

The actual cut of course is nowhere near .06.....

Z Decimal point location very important on this item:)

[Brady Watson]

Yep...In the shop scratching your glass again :D

Looks good! Did you run a diamond drag or ??? Router spinning?

A few years ago I mounted a TurboCarver to the Bot and while slow-going, it would engrave just about anything you put on there.

-B

[curtiss]

I first tried a "from China diamond bit" that did not last very long and then switched to a steel engraving bit.

Router was running about 16,000 rpm, 1.5 ips

So are you saying the "diamond drag bits" are not spinning when engraving ???

[Brady Watson]

So are you saying the "diamond drag bits" are not spinning when engraving ???

Yeppers...A diamond drag engraver does just that - it drags across the surface using it's hardness (hardness = resistance to scratching) and isn't spun in the tool holder or spindle.

Check it : Youtube Vid Example (http://www.youtube.com/watch?v=h-kqaP7nX6I)

-B

[dan_nelson]

is there any disadvantage for using an engraving bit spinning compaired to a DD bit dragging for etching glass we are just trying this for the first time any advise ?

[curtiss]

is there any disadvantage for using an engraving bit spinning compaired to a DD bit dragging for etching glass we are just trying this for the first time any advise ?


I had a rather poor quality diamond bit... but I would guess a proper one would do much better.

The steel engraving bit did fine about about 16,000 rpm. Wear safety glasses... next time I would spray a bit of water on the surface.

[dan_nelson]

How did it work for say an area clearance and what stepover or did you just do a straight/ curved line work on your design and lettering

[wberminio]

Have you tried Widgetworksunlimited Diamond Drag Bit?
http://www.widgetworksunlimited.com/CNC_Specialty_Bits_s/33.htm

Simple and it works!

[knight_toolworks]

heat kills diamonds so spinning is not the best idea. a spring loaded drag bit is great for such work. gives you control over pressure.

[dlcw]

I've used Widgetworks diamond drag for etching some brass and it worked very well for that too.

My next adventure is to try some glass etching.

[dan_nelson]

we ran a sample piece ,lessons learned were, you can run an hss engraving bit at 16k and water cool it . table doesnt have to be exactly flat if you have the glass padded we used a tool box foam liner. the vectors you use should be of the single line type (too close together caused some chipping )and the bigger the better for clarity. Thanks for all the info as always Bridget and Dan Nelson

[knight_toolworks]

I forgot also with the drag bit you use the engrave toolpath and it has filling options. I have a sharpened carbide point on mine I want to try on glass. Mr widgeworks did not invent his in time and I had to buy the 300.00 one that one can be spun. but I get cleaner lines without any spin.