Need Help - Simple Galvo Setup

I'm looking for a starting point for a simple setup to draw an image with a single laser. I help out with a Haunted House every Halloween as a benefit for a local organization. We've got a 50,000 square foot warehouse that we own for the event so we're trying to get a jump on changes for this year. One of the rooms we're adding is going to be a twisted "Alice in Wonderland" type room. So where does the laser come in, you ask? Simple. The Cheshire Cat.

The "room" is a wide hallway area about 20 feet long by 10 feet wide. My plan is to paint up the room in largely fluorescent colors on a black base. For the "Cheshire Cat" effect I want to use a Blu-Ray laser and Galvo system to project the "Grin" and various facial features at different points in the room.

The downside is that I'm on a pretty tight budget, so my question to everyone here is what is the simplest and easiest way to go about sett up my "Cheshire Cat Projector"? Would a scanner setup like this one work or am I going to need something more expensive? And what else will I need (besides the laser of course)? For the laser, I am planning on using one of the etimeshop specials.

Any help will be greatly appreciated.

Well for a litle bit more you might be able to pick up some used galvos between 15-20k for under 100$.
You will a correction amp (You can build one for cheaper, I tried and failed, but who knows you might have better luck than me.)
http://hacylon.case.edu/ebay/laser_diode/LaserBoy_Correction_Amp.php
laser driver ttl
http://hacylon.case.edu/ebay/laser_diode/FlexMod01.php (You can build one very simple.)
Software, laser boy or LFI both are free.
The galvos you buy should come with there own amp and psu so that is all your going to need.
And for a blue laser. i would go for the more expensive one it will last longer and is better but you have a budget.
405nm PHR-803T Blu Ray Diode in Aixiz Laser Module Housing [PHR-803T in Aixiz module] - $19.83 : High Tech DealZ, Simplifying the LASER Hobby!
405nm GGW-H20L 6x Blu Ray Diode in Aixiz Module +650nm LCC diode [GGW-H20L] - $56.82 : High Tech DealZ, Simplifying the LASER Hobby!
Then some sort of project box a large size at radio shack.
But other than that you should be fine.
So
galvos 100$
Correction amp 40$
Laser 20$
Laser Driver 30$

To build a projector for drawing images you'll need a set of real galvos, 20kpps or higher, a laser module that can be modulated, and a computer and DAC interface to control it. If you were only planning on projecting simple beam effects then you could get away with less, but images and graphics are the most demanding effects you can do, even if it's just a cheshire cat face. Your absolute cheapest option is to buy a cheap Chinese RGV projector and an ishow DAC, but such a system will not be legal for public use in the US..

Personally I'd recommend using an LCD projector instead due to the cost and complexity of buying or building a laser system to do the job..

The links kiyoukan posted are very good and informative. Building a laser projector is extremely educational and a great deal of fun, but if all you want is a cheshire cat for this one event, it's not very cost or time effective.

EF,
I got a pair of 15k galvos doing around 18k and they draw very good.
The ilda pattern come out great, along with any words 8 chars or under.
You can pick a set of old 15k galvos cheap. new 20ks go for with shipping 139.99$
So a used 15k go for some where around 45-70$ As they are used and outdated.

Very simple no need for 20ks, but i will agree they are a better investment and will be more usefull in future effects.

If you can get a set of slower, used, galvo's, they would probably suffice for what you want to do. Otherwise, you need a set of galvo's in any case, and you could do with the spacelas 20k scanner set (at about $130 shipped).

Bear in mind that this is no easy project you will get to work in a spare hour though. If you have no experience with laser scanners whatsoever, it might take a day or two to get something functional.

Its feasible as a DIY project, but by no means an easy one to get running properly. Some experience in electronics will help things, but even then it requires some tinkering.

Thinking about it now, For the simple image he wants which is a crescent moon with some lines, this is a shape a stepper motor could do with a pre programmed controller. The laser would not even need to be modulated. There is no need for blanking so a cheapo driver will work.
This would save some money, the motors you would need 2 would be around 30 total and the custom made and programed controller could be made for between 40-75$
Now the ones you posted are very interesting. they "could work", There is no way to tell till you get them and see what they can do.
You need to be able to program them, i am unsure what they even are i see only 2 wires for each of them so i would think they are able to use sound so you could use a pc interface.
I hate to say this but if you buy those you will be flying blind but i would be very interested in what they can do.

Stepper motors wont really work, since between their steps, they will distort the image, so it won't look much like the image.

For something like that, even the cheapest set of galvo's will work.

You mention you want to draw various parts around the room> For that, you will need blanking. You also mention wanting to do it in blu-ray, this could be a problem as blu-ray is very dull to the human eye, compared to another colour like green. You are going to need a lot of 405nm laser to produce a good effect, when maybe 50mW of 532nm green would do much better.

I figured he was painting the room with fluorescent color, so it would work very well with a bluray laser. The laser beams wouldn't be very visible, but the projection would stand out very well, might in fact be a very interesting effect!

Benm said:

I figured he was painting the room with fluorescent color, so it would work very well with a bluray laser. The laser beams wouldn't be very visible, but the projection would stand out very well, might in fact be a very interesting effect!

Click to expand...

This was my goal. Have the beam be mostly invisible, but by changing where the face is projected the color of the face will change (based on the background paint)

As for the stepper motor thing, I'm actually looking for more than just the "grin" part. I would like to be able to project a full face, parts of a face, have them fade in/out etc.

I'm reasonably good with electronics, robotics and software, as well as fabrication and mechanics so the general construction shouldn't be an issue for me. I was mainly looking for advice on parts lists, etc.

If I build this unit, it will definitely be more than a "one time use" unit. It'll go into our inventory of props. I might be able to swing it this year because out organization has received a government grant that covers the majority of our day to day operating expenses so our budget for the Haunted House benefit can go up a bit.

If I can build a laser scanner cheap enough I may build a second one because I've always wanted to be able to do something like the "Red Queen" from Resident Evil. That little girl hologram is sooooo creepy when she says "You're all going to die here." in her matter of fact British accent.

Well then the list of parts you will want as followed:
Galvos, PT-20K from PT-20K PHENIX TECHNOLOGY 130$ With shipping
LaserBoy Correction Amp, http://hacylon.case.edu/ebay/laser_diode/LaserBoy_Correction_Amp.php 40$
analog laser driver http://hacylon.case.edu/ebay/laser_diode/FlexMod01.php 30$
External USB 6 Channel 5.1 Sound Card External USB 6 Channel 5.1 Sound Card PCI for PC Laptop - eBay (item 360260132129 end time May-11-10 19:41:58 PDT) 22$
Laser, 405nm GGW-H20L 6x Blu Ray Diode in Aixiz Module +650nm LCC diode [GGW-H20L] - $56.82 : High Tech DealZ, Simplifying the LASER Hobby!
60$
So a total cost will be around 282$
A tutorial to put together the Computer controlled part.
Sound Card DAC Tutorial
Now there are many more options you can add to your scanner at this moment this scanner is only controlling 1 laser but the laser can fade in and out or on and off, Analog modulation.
You could buy 2 more drivers and 1 green laser and 1 red laser plus some optics and make a full color rgv scanner.
once you start adding in more lasers it will get a lot more complicated. a cheaper alternative and maybe faster is make the laser and their drivers removable so you could put a red or green laser in.
The laser you bought come with a red laser. you can save this for when you want to add in another color you will just need a housing for it.
This would save you the optical beam alignment problems.
I might suggest you go into the bst section and buy a used scanner also post here for one to Photonlexicon.com.
Building one of these is no easy task i have been building mine for over 3 months and am almost done.and have spent a good amount of money on it.

That sound about right. If you're good with electronics, you can build the correction amp yourself for a lot less, and that may apply to the driver too.

As for the laser itself: you might be able to get what you need from a cheaper (lower power) PHR803 diode. On their own they arent all that bright, but when used on a fluorescing surface, things can get pretty bright (comparable to 50-100 mW of green).

You'll also need a power supply for the laser - you can rig one yourself, should be expensive.

Most of the cost will be in the scanner set in any case, but that's really worth it if you want to make something flexible.

The reason i put that laser is just because it will last a long time even being ran for long periods of time. a phr pushing 100mw is not going to last as long as a ggw at around 175-180, Also if he plans to add in green and red this will give him a good ratio for other colors.
But This needs to be decided ahead of time how far you want this laser scanner to go.
like i said before you could have it one color at a time just pull one out and put another in, no optics needed.
Trust me if your going full color you will be fighting a up hill battle.
We will try to help you with questions or diagrams as much as possible but the hardest part imo is fabrication. Having access to a machine shop is not needed but can save you lots of time.

i don't know anything about scanners i am still learning but olike sells 405nm modules with ttl for pretty cheap. I hope this is useful

Not to hurt olike but i heard their drivers were crap but i could be wrong.

their main drivers are crap. but i havent seen a review of their ttl one on the violet. and even if it is crap. its ok because it is only getting used once a year.


michael

He mentions wanting to fade in/out, you can't do that with a TTL laser, well, at least not without LivePRO.