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[JamesB]

Now that I have your attention ...

The above piece of engraved glassware is a one-off item I created back in September of last year from the Semper Legens tattoo/t-shirt design that Jeph posted on the comic site.

Amongst my toys at home, I have a serious LASER engraver/cutter (definitely not a cheap Chinese model like they sell on eBay) that I use for some of my craft work. The Semper Legens "double old fashioned" glass took a number of test runs on a few sacrificial glasses to fine tune the image (I go through a lot of glasses when I'm developing a complicated piece), but the end result came out rather well. The test run glasses were all smashed after I got a result I was happy with. If I ever get a shipping address for Jeph, I'll send it to him. I had planned to give it to him at the lecture he did at the library in Halifax back in January, but it's a 3 hour each way trip to Halifax, and the weather on that date was not the best for a long highway drive at night.

I have some art skills (can do acceptible pencil, pen and ink, and air brush work), but I'm more a technical draftsman/designer and fabricator than an artist.

Most of the work I sell is custom engraved glassware, but my machine can also do amazing things with wood.



This shade over 6 inch tall TARDIS model was designed in CorelDRAW and constructed out of 3mm Masonite that was finished and then painted. I've been working on this design for over 5 years, and the one in the photo was commissioned in late 2014 as a presentation box for an engagement ring. Click the images for high resolution versions.

Here's a photo showing details to give you an idea of how it looks without paint or any finishing. The model in the this photo is just the raw, freshly cut and engraved wood.



Except for the cage around the light at the top which has been glued together, everything else is unglued and just fitted together. I originally designed the model as a puzzle that required no tools or glue for assembly, so the parts fit together quite tightly. Any minor variation in the Masonite stock I buy can cause all sorts of assembly problems, so I often use a micrometer to measure the thickness of masonite sheets in the hardware store.

Once the paint goes on, the details spring to life.



The LASER engraver/cutter is a great toy tool, and to the computer it acts like a big printer with a printer driver that's got a few more options than most standard printers. The tricky bit is getting the LASER power and cutting speed just right for the design and the material you are working with.

[Akima]

Fascinating... Does the laser "head" move in straight line? In other words, did you have to project the logo onto a flat plane to develop what you wanted to "print" onto the curved glass?

[JamesB]

The engraving on the curved surface of the glass is done using a "rotary adapter". Basically it's a stepper motor driven chuck system (like a very simple lathe) that slowly rotates the glassware while the laser head scans back and forth.

This YouTube Video shows how it works.  (You may want to turn your audio down as the cooling and extraction fans are loud)

The laser head moves in the X axis only while the glass is rotated by the adapter. The need to keep the 2" focal length lens in the moving head within about 2mm of perfect focus restricts how much of the curved Pilsner glass that can be engraved. The infrared laser beam enters the head at the top left.

When you're engraving a flat object, then the laser head moves in both X and Y axis. This YouTube Video shows that process.  (Again, you may want to turn your audio down as the cooling and extraction fans are loud)

This particular engraving uses 3 separate engraving modes. A back and forth Raster Scan to mark large areas (rather slow process), then a Vector Marking mode which moves along the path being engraved and produces a fine line without cutting through the wood. Finally there's a Vector Cut mode which does the same thing as the Vector Marking but with more power and/or less speed to cut right through the material.