I've been looking at similar setups off of ebay as well. After some more digging, I found the ILDA specifications here (PDF link). The "show card" basically looks to be a card with various preprogrammed displays, as well as having breakouts for TTL laser control and interfaces to the galvanometer amplifiers.
The ILDA spec shows that four pins, +X, +Y, -X, and -Y could be used to get direct XY control over the galvos. They take a +/- 10v analog signal, and that's spit into the amplifiers on the galvos and translate to mirror movement. I guess where I'm lost is how to go from the standard reprap method of "send N pulses at frequency F to go distance A on the X axis at S speed" to "send analog voltage V with a ramp rate R from the previous voltage to go distance A on the X axis at S speed". I know I gotta go through a DAC, but that's where I get lost.
I'm also starting to maybe lean towards a super lightweight delta bot, since I have the experience and the equipment to make most, if not all the moving parts out of carbon fiber and CNC'd aluminum. It still would be slower, but it would be way less work, and arguably less expensive, than fiddling with moving optics and writing custom firmware.
The ILDA spec shows that four pins, +X, +Y, -X, and -Y could be used to get direct XY control over the galvos. They take a +/- 10v analog signal, and that's spit into the amplifiers on the galvos and translate to mirror movement. I guess where I'm lost is how to go from the standard reprap method of "send N pulses at frequency F to go distance A on the X axis at S speed" to "send analog voltage V with a ramp rate R from the previous voltage to go distance A on the X axis at S speed". I know I gotta go through a DAC, but that's where I get lost.
I'm also starting to maybe lean towards a super lightweight delta bot, since I have the experience and the equipment to make most, if not all the moving parts out of carbon fiber and CNC'd aluminum. It still would be slower, but it would be way less work, and arguably less expensive, than fiddling with moving optics and writing custom firmware.