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Projecting light on a surface for marking.

  1. Mar 2, 2008 #1
    I was wondering if anyone knows if such a device exists that would (ideally) project a ruler onto a surface. I assume that this projector would have to be laser based since it would need to work within a range of about 5 to 20 feet away from the target without any divergence. So imagine the operation would be:
    Turn the device on, a ruler is projected onto the target which may or may not be a curved/irregular surface, but always approximately a verticle surface. The projected laser beam would need to always be horizontal. I plan to mount the device on a turntable to rotate the beam to a different part of the object, but the whole ruler would stay at the same level no matter how you rotate the projector.
    Devices similar to this exist for surveying and grading. I've used one, there's nothing too special about them. The difference here is that I want multiple marks, not just one dot.
    As previously stated, ideally the device should be a ruler marked off in inches like a cheap desk drawer ruler that is 1 to 2 feet long with resolution down to about 1/8 inch. However, I'm flexible. I might settle for something less. For instance, the inches would not even need to be marked in numbers. Just dots spaced an inch apart. The half inch marks could be shifted slightly to one side and quarter and eighth inch marks shifted the other way.
    Does anything like this sound familiar? I can envision lots of ways to build such a device, but not in small quantities cost effectively.
  2. jcsd
  3. Mar 3, 2008 #2


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    Hum. That's a tough one. I can't say I have come across anything like that. Even so, even if a laser is used, the beam will still have a spread over long distances. There's not a whole lot you can do about that. It's the nature of the beast. You might want to check with Banner: http://www.bannerengineering.com/
  4. Mar 3, 2008 #3


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    I think it sounds like a great idea, the laser pivots at a point that would be center, so it seems to me that any object that receives a spot of light will have to be calculated, based on how far it is from the center, this will change the value of measurement for any portion of a degree along a flat wall.
    With computer adjusting software, i would think something could be worked out.
  5. Mar 3, 2008 #4
    It's not meant to be a real precision operation. Naturally any light including laser will diverge, but the distances involved with my project should not cause a problem. Thanks for the link Fred, I don't have the time to check it right now but I'll get on it later today. More opinions are welcome. :)
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