Re: GB: Low Cost 15K Scanner Galvo Set with DMX & ILDA Complete - $75
If you are all getting these, you will all need a DAC or else a DMX controller. You could read up on the differences, but a DMX controller will only allow preset patterns determined by your scanner. A DAC is much more flexible, but may take some time to put together, or else is pretty expensive to buy. In order to build a sound card DAC, which many hobbyists here do, you will need to purchase:
http://hacylon.case.edu/ebay/laser_diode/LaserBoy_Correction_Amp.php
and should have an oscilloscope in order to tweak everything to the right settings... I'm not sure how others may have done it without an oscilloscope. You will need a $15-$20 usb sound card as well. You will also need a laser with TTL or Analog modulation. TTL is on-off, analog is adjustable power. Analog is more expensive, but allows for more colors when combining with other lasers using dichros. It will also be hard to combine these beams without adjustable/kinematic mounts.
*By the way, if you decide to use a laser without TTL or Analog modulation, then the graphics will appear as a continuous curve. The difference can be referred to as blanking. It's pretty much a necessity.
Good luck to everyone tackling this project. I started it years ago, but never got around to finishing it. I plan on making a complete system this summer. Of course, I'm giving you guys just the basic information. I would read up on photonlexicon for more info about these sort of systems, since this forum is designed to cover Laser Pointers, whereas that forum is designed to cover Laser Projectors.
As for speed, 15kpps means 15 thousand points per second... these are not often used for graphics, though they can be, but are more used for beam shows. Generally people start with 20kpps for graphics. Of course, you can obtain different speeds depending on your scanning angle (how wide you turn your galvos). These are considered a step upgrade from stepper-motor systems (which are solely used for beam shows).
Edit: If anyone feels that anything I mentioned was false, I'd be glad to correct something.