Help with clock project

Hi,
I'm brand new to this forum and any sort of laser science. I'm trying to educate myself as I work on a project that I'd like to use lasers in if I can. I want to make a laser clock. Pretty straight forward, I figure the minute hand is one color laser and the hour another color. However, with my (very) rudimentary knowledge of lasers, different colors means different visibility in air. I'd like visible lines from the center point to a specific distance away from the center (to make the hands). I plan to use either mirrors or a prism to end the beam unless theres a way to make a laser taper off the end. I've seen projection clocks, but I'd like to make an installation where the lasers are situated on a center piece that (with other circuitry and mechanics) turns to the time, separate project. Would this mean I need another medium for the laser to travel through to make the beam visible? if so what sort of medium, I would need this to be mostly or semi transparent to see mounted artwork behind it in the day or when the laser is off. So to get to my question: what color laser is most visible, are there such color (and power) lasers that are either prefabricated in a square or flat/rectangular shape which can be modified to be controlled with a separate IR controller, and if theyre not prefabricated whats my best bet in terms of power, color, components, etc?

Thanks for the help

Before you zap yourself, try building the mechanical part of the clock before you attempt to rig a blinding laser to it.

well well, my friend gave me this idea yesterday. Hope to see a laser clock soon

To answer some of your questions:

The most visible wavelength is green.
The beam will be most visible through a dense medium like liquid or clear acrylic.
The beam cannot "taper off" at the end, it travels until it is absorbed or otherwise attenuated.

Your idea here sounds cool, but also expensive and the work may be very tedious. Also, this clock will want a lot of power to run continuously. Take that into consideration.
I'm not sure how you plan on "stopping" the beams individually where you want to.
I also am unsure how you plan on mounting the lasers to the rotating motor so that they can turn freely without wires getting twisted up.

Why not use a UV LED backlight and fluorescent or glow-in-the-dark hour, minute, and second hands?
It could be a cool effect and cost much less. And construction won't be as problematic.
Just an idea.

Why not use the ceiling as a beamstop / projection surface?

I have an alarm clock that projects time onto the ceiling with just a LED and LCD, and the end result in very usable.

I've been building different sorts of clocks for a while now. So I'm not worried about those mechanics. I'd seen a lairge projection laser clock installation, which inspired me to want to make one lol. I don't know if anyone here has heard of a program called the rasterbator (yes... name is funny... haha). It basically takes any image and converts the pixels or groups of uniform pixels into dots of different sizes (for lightness, darkness) and color. This way you can mount these images (printed on normal size 8.5x11 or similar consumer paper size) on a wall and have an incredibly large image from something that didnt necessarily have the required resolution to be that big. I've had some experience putting these in and a friend recently asked me to put one in her apartment. Shes a rave girl (awesome, I know) and has a lot of odd lights and ambient (I don't know if thats what you call them) lasers in her rooms. basically she doesnt run any normal lights and only has things like black lights, christmas lights that flash, and lasers... I dont know how she cleans but her apartment is always nice looking otherwise (not to say lasers arent cool, but I sorta expected the dimly lit rooms of raves to go hand in hand with the oddly sticky floors and always empty beer cans lining the room) anyway, she wants a laser clock. So I set out to find out how to make one. I'm not shy about soldering or reading schematics.

After that long winded background story, to answer a few of your questions to help you answer mine:

I will probably end up mounting the rasterized image on the wall with two pieces of acrylic (or a few seperate pieces but two layers) with the image sandwiched in between. I figure if the outermost layer is thicker (say 1/2 in) I can shine a laser through this, parallel, so the beam is visible within the material. My question about "tapering" I think was worded wrong. If I was to have the beams on a slight angle from the acrylic (if y is 1/2 in and I want a 3 foot beam I could have a 9 degree angle relative to the acrylic). My question therefore is more about the defraction/refraction of the lasers. Well I spose, because I have forgotten just about all my physics of light, my question is will this get the desired result? that is "end" the visible beam of light as it exits the material?

Second, I could also simply "end" the beams with a non reflective surface around the edge of the acrylic, or would that create too much noise or extra light inside the installation?

In order to keep the wire from becoming a clusterfkk I'm planning on using a few donut gears and a larger piece in the middle which I will fix two spinning chambers in the center to keep the wire where they should be going. If that doesnt work, or I run into more complications as I plan this to more detail, what sort of mirrors/prisms could I use to create coherent beams as they rotate in a circle? I know if I rotate a square prism with a static laser pointed at it I only get kind of a half circle, which would make it rather hard to read the clock during certain points in time... though, if I calibrate it right this may be ok since the installation wouldnt need to be on during the day (she has a lot of windows, and I am jealous of her place...).

Third, I'm planning on putting a second hand at the end of one of the lasers. I figure I can have a prism rotate around the center of the clock (more gear work than anything) following the path of the minute hand. this prism would then either tick (oscillating motion) or spin to show seconds. any thoughts, concerns about this?

Thanks for all your help! Hope to hear from you all soon

Are you planning to project the clock hands within the acrylic material? I'm not sure i understand your description, but it sounds like you would have a hole in the middle of the plate, in which a laser rotates (or hits a rotating mirror or something), resulting in a clock hand motion... right?

Yes thats exactly it, if I was just installing a clock I think there would be easier ways to do this, but since I'm wall mounting art behind it, the acrylic would be used for that anyway. So in the center of the whatever material I end up using I'll cut a hole in the center to put the laser components in (probably housed in wood) that is at the same level as the material to project through it.

Wpecka said:

I want to make a laser clock.

Click to expand...

I think he saw this video but this setup as a rough 2500 dollar clock

Thats freaking awesome! I haven't seen that video but now I do want one ^_^. Again, I'm not trying to make a projection clock, I want to make a clock with laser hands, where the laser component is housed inside the clock, that is, there is no projection from a far wall. My friend's budget for this project is around 1800 after the image install.

well you need a HUGE clock housing it's not going to be small

Look, I'm not fully aware of cost, time, size of these things, if I did I wouldn't be asking on a forum. Please stop trying to turn me away from this idea. I asked a few very specific questions, if what I am asking is impossible to do (and with my limited knowledge I'm pretty sure its not) then tell me. If it isn't then please let me know how to do it.

How big of an enclosure am I looking at? and what will make it so large?

well i am not sure how you think as in a clock work ? 8" x 8" x 4 " ?? or can it be BIG HUGE you need aircoolers for the DPSS TEC cooled laser modules it will be the size of a medium PC case not a little make up box ( to give you a view of things ) + you need even a pc or laptop to control the laser mirrors ( if i think that is the 1 way ot make a clock work with laser beams )

I finished building a laptop wall mount a few weeks ago, basically just ripped all the components out of an old laptop, added power interface, lights and then rigged it into a square wooden box. changed a couple of the startup options, runs windows 2000, stripped down interface. boots into a media interface and ive been playing all my data from a nas drive attached to a projector. I could build another one of these to control the device. I was hoping thered be a way to keep the device around 12"x12"x3". the entire installment will probably be around 8'x8'