I’m delighted at how well the lunar clock is going! While waiting for stepper motors to arrive, I’ve been using Inkscape to create the laser-cutting pattern for the wheel that will contain images of the various phases of the moon. After a few hours of stumbling around (I’d never used Inkscape), I was drawing circles, arcs, and lines with abandon.
The idea of the clock is that this wheel will be behind a picture of a sky, that has a moon-sized hole near the top. The wheel will rotate to show the lunar image that most closely resembles the current phase of the moon.
I had hoped to put12 lunar images in the wheel, but that made the wheel too large and the lunar images too small. 8 images makes everything just the right size.
I’ve never done laser cutting before, so I signed up for Ponoko, a popular laser cutting service in New Zealand and the United States. It’s been a breeze ordering my first Lunar Wheel, to be cut from a 15-inch-square, 1/8″ thick piece of MDF. I simply downloaded the template into Inkscape, followed the design rules, and voila!
One cautionary blog called Scale Fail recommended that you prototype for laser cutting in 3 stages:
- Test the size. Print your design full-scale on your paper printer and see if it looks right. This is the stage pictured above: I’m checking that the screw hub holes are properly placed and are the right size, and I’m checking that the slot is the right size to make the photo-interrupter work well.
- Then laser cut in cheap cardboard. You’re likely going to make some mistakes (even small ones), so it’s good to get through them using cheap materials.
- Now print the real thing.
Since Ponoko offered a $20 discount on my first order, I decided to skip cardboard and go straight to MDF. It will be a good test piece regardless of whether it works out. Without the discount, the pattern above, in the MDF I described, shipped to me with a little speed, would have cost about $30. Not bad considering that to make another I just push a button rather than spending a weekend with the scrollsaw.
Now I can’t wait for my Lunar Wheel to arrive!