--- In
Homebrew_PCBs@yahoogroups.com, "cunningfellow"
> I had never even considered the posibilty
> of trying to line up 8 lasers at 0.025mm
> spacing.
>
> I cant even fathom how it would be done
> at home.
Well, I actually built the laser pattern component. What I did was get a roll of communication optical fiber. I stripped one end of 8 fibers and carefully scraped off the protective plastic cladding, just leaving the bare glass fiber. I machined a round part that split down the middle, and then made a groove in one side that was 125 um deep and 1 mm wide, and laid the 8 125 um OD fibers side by side in the groove, smeared a little epoxy on it and then clamped the other piece over it. When the epoxy cured, I cleaved the fibers and polished the whole thing. I proved I could rig up a laser and sphere lens to light the fiber. I have no idea how much of the light actually made it into the fiber, or how efficiently the fiber radiated the light out the other end. So, the plotter worked well enough that I put it into use and never completed the 8-beam modification.
Yes, you'd have to deal with rotation of the fiber array, PLUS getting the magnification just right so the 8 beams all fell in the right raster lines. I can imagine test patterns that would help in making the adjustments.
Jon