Quote Originally Posted by nerdthingy View Post
Okay, so I had an idea for a "galvonometer." It's basically the laser is on a spring loaded hinge with a pick/needle. A spinning gear is catching on the pick, which rapidly vibrates the laser. the faster the gear goes the faster the laser goes. would this work? Or does this already exist?
The question "would this work" is perhaps not the right question; the question should be "what will this do?" And, the answer is, you will have something that produces a relatively short line by scanning a laser in a roughly sinusoidal pattern with frequency based on the spring constant of the spring you choose and the impulse provided by the gear/pick interface. If you put two of them in an X-Y arrangement, which is going to be difficult due to the geometry of the motors, gears, picks, and mirrors, you will get a lissajous pattern adjustable over a small range. At the end of the day, you'll either be really excited that you did something and it worked out the way you planned it, or disappointed that what you built didn't meet your expectations. The experience will be valuable to you either way, but personally I like to do a little more picturing of what's going to happen and a little more drawing of how things are going to go together before spending time and money putting it together so I have a better chance of ending up with the former outcome vs. the latter.

If you try this, maybe post some pictures as you go so we can see how you're doing and answer your questions.

Good luck!!