DIY Christmas Laser Light Show

erco

I saw that $40 "Star Shower" laser christmas light display in the store, but it's static, no motion. Some research showed that moving laser lights are $100 or more, so I did what any good DIYer would do, I made my own from parts I had laying around. My balloon-popping laser (IIRC ~$12 Ebay) came with a rotating diffraction grating safety cap. I slapped a gear & motor on it and clipped it to my car's window. Everything's powered by a 6V SLA battery, which should last for my 4-hour Christmas party.

erco

Yay, the laser, mechanism & battery all lasted beyond my 4-hour party requirement. As a bonus, I wasn't arrested for downing any aircraft on final approach to LAX. My official photographer caught this interesting starburst effect through his lens, which is not the way it looks to the eye. Very cool though. The laser is behind the camera, projecting through a diffraction grating.

hazlett

Four hours is not bad anymore for Christmas party. On the other hand, I wonder if 12V SLA can be also use for that?

erco

It was actually more like 5-1/2 hours before everyone left and I powered everything down. I needed 6V, so I ultimately used 2x 6V 3AH SLAs in parallel. IIRC the draw was ~330 mA. One good new battery would have sufficed, but these particular BB batteries were from 2004 so I doubled up for insurance. Still going strong, I've had newer batteries fail.