Home made RGB laser

http://c4r0.skrzynka.org/_hv/?page=lasers/RGB

Category:

Science & Technology

Tags:

• RGB
• laser
• projector
• lasershow
• 405nm
• 650nm
• 532nm
• green
• red
• blue
• violet
• bluray
• yt:quality=high

[dasimpsonsrule]

Wow, thats probably the only use of an HD DVD player now :D

[tdneVmo]

RESPECT! OMG i would like to make one of those!

[c4r0hv]

@umloginqualquer

Man, I'm glad I can help. You can check my website at c4r0 . skrzynka . org but the server has been randomly up and down for the last several days - right now it doesn't work. I'm working on taking care of that but it may take some time. If you have any more questions, shoot. Good luck with your project!

[umloginqualquer]

@c4r0hv I'll never be able to thank you enough. You're awesome, dude! Thanks for all your will to share your expertise and knowledge with other fellow enthusiasts. =D Greetings from Brazil.

[c4r0hv]

@umloginqualquer It's different than servos cause it's faster, but the idea is similar. Check the ELM ChaN projector, you have everything explained there. That one uses capacitive position sensors, but commonly available galvos use optical sensors. All my laser projectors (check the newest one at w w w elektroda pl / rtvforum / topic1676990-0. html ) use LPT port based controllers called POPELSCAN. This is an amateur design which has been used by amateurs many times.

[umloginqualquer]

@c4r0hv Closed-loop systems, like servos? Very interesting. Now that I know the right search terms, I'll spend a eternity on google. And, if that's not some kind of secret: what kind of hardware and controlling software (assuming a computer-controlled system) did you use? Did you use off-the-shelf products, did you build something accordingly to a existing project, or did you design your own?

[c4r0hv]

@umloginqualquer There's three things: 1. low inertia (low mass of moving parts) 2. high driving force (strong magnets and coils) and 3. good, well tuned PID controller. You ABSOLUTELY need closed-loop control, i.e. position sensor and PID driver. Speaker mechanism can be used for that but IMO it will be very slow and hard to make it work correctly. You can actually build real galvos by yourself - google for "elm chan laser projector".

[umloginqualquer]

@c4r0hv Btw I just found out how Galvos (aka galvanometers or scanners) work. They also use electromagnetic methods, somewhat like the speaker idea I was considering. Probably the key to get greater scanning speed (more points per second) really lies in reducing axis+mirror inertia. See laserfx. com/Works/Works3S.html

[umloginqualquer]

@c4r0hv Hmmm. I was considering a more DIY approach, using two perpendicular speakers attached to the tip of the laser pointer to control the inclination of the laser in X and Y axis. Maybe they would have less inertia (and greater speed) if they control the inclination of tiny mirrors. I wonder what else I could use for this purpose, besides speakers. This guy used a HDD head: hackedgadgets. com/2006/12/02/ten-dollar-xy-l­aser-scanner/ and I like this video description: watch?v=APO74lvh78o

[c4r0hv]

@umloginqualquer

It's always mirrors. The idea and principle of operation is always the same. The more complex stuff you wanna draw the higher scanning speed is needed. This is measured in points per second (pps). My galvos are 12kpps if I remember correctly. You can get as much as 50kpps, maybe even more, but the higher speed the more money it costs obviously.

[c4r0hv]

@chucaswatjfan

I guess it's just the camera.

[umloginqualquer]

I'm interested in making a laser show too, but I'm undecided about how to get them to draw complex stuff. Do you know if people usually use mirrors for this purpose, or do they use another method? It would be awesome if you could provide a link explaining how to do complex drawings with mirrors or discussing other methods to draw. Thanks!