Well, things have not been moving as quickly as I'd like. I want to have a working prototype by Oct 7, so I can take one to the conference at NYLS. But time and money have proven to be big constraints.
At the moment, I have a bunch of ideas that I need to iterate through rapidly. I know some of these ideas are just not going to shake out in my Maya model of the portable scanner, and I need to make them out of real stuff to figure out how to place things and see how they work.
Real stuff is a problem. 5mm baltic birch plywood is cheap, but not so cheap that you can waste it. And you can only cut it at 15% speed, which means that even this little box can take over 20 minutes to cut. If you make a mistake, that's another 20 minutes just to keep moving, and you'll probably chuck the part anyhow.
But with less-dense materials, much higher speeds are possible. So much of my book scanner time this week was spent looking for materials with identical thickness, but with much better cutting properties. One of the contributors over at Sawmill Creek Engraver's Forum pointed me to foam-core
. I tried it tonight.
It turns out Wal*Mart was the cheapest source of foam-core that I could find. I hate Wal*Mart but I have to stretch my money as far as possible. I bought six sheets of 20"x30" foam core, which is just slightly thinner than my baltic birch, for $3 a sheet.
When I got back to my workshop, I remembered that I had another kind of foam-core somewhere. I think it is the more sturdy material mentioned in the thread above. It has a thicker, stiffer "paper" covering around the styrene center.
I cut my test box from both materials. On the left is the baltic birch ply. In the middle is the stiffer mystery foam core. On the right is the Wal*Core. Laser settings: 100% speed, 90% power, 1khz. The styrene core of this material is kind of interesting. You can see that the heat from the laser causes it to go concave. It also produces a lot of noxious-looking smoke which gives the impression that it's much heavier than air, because of the way it lingers in the laser.
Conclusions: Mystery-core is great, but probably more expensive than ply. Wal*Core is junk, but probably good enough to try out some ideas. Tomorrow night is reserved for trying a proto of my folding lighting arms.
Behold, the new DIY Book Scanner HQ. Basically, it's a workbench I made from 2x12's in a moldy basement. The great thing about this setup is that I will be able to put the laser down here in the winter. It would definitely not survive the harsh winter in my workshop. The first cold snap would mean the end of any laser work. I've lived in this flat, featureless, artless state most of my life, and winters here are absolutely brutal. But for me, the brutality is not the extreme cold or the mountains of snow, it's the total end of workshop activities. I may have left my preferred dwelling, but being closer to my machines and projects should keep me going through another Fargo freeze.