Advice for daylight line laser

[Wooly]

I’m coming to this forum as a noob for some advice. I’ve tried using the search, but to no avail.
I want to attach a laser to a tool in order to align it correctly. It needs to project a line of up to 20” in length from a distance of up to 24” away from where the laser is mounted. I believe I will need something that projects a 45 degree fan. The line needs to be visible in outdoor light conditions including bright sunlight.

The unit needs to be as compact as possible. It will work intermittently, say on for 5 seconds, off for 30 seconds or more. It will be battery powered (3V). Of course, it needs to be as cost effective as possible.

So my question is, what do I need? Green laser? red laser? Diode? What output? etc. I’m looking for suggestions as to what will give me the visibility in daylight conditions. I’m not a techie, so please keep it simple.

Thanks to all in advance.
Wooly

 

[Fenzir]

I'm not so sure about your entire mirror setup, but are we talking bright day, no cloud, noon bright? Because that would need a pretty lot of power then. Also, how bright does it need to be? Do you need to blatantly see the line or have it so it's just visible? I guess green would be your best bet seeing as it's more visible to the human eye than red but I don't know too much about this :/ I'm sure somebody knows though, we got a bunch of people around here that are technology wizards.

 

[DakotaDaNative]

green sounds like your best bet and perhaps 50mw? but id be worried about reflection if you were using this on something like table saw or mill. and what your looking for is a line generating module and i haven't read it anywhere but im pretty sure its the lens in the module that creates the line. and just like Fenzir said it all depends on your lighting conditions.

 

[aryntha]

I'm going to go out on a limb here and say depending on the distance and focus of the fan, 10-20mW may even be sufficient in daylight.

Why? He says it only has to be 24'' from the target and 20'' length. Personally, I can see my 1mW green (spot of course, not line or fan) from a good 20 feet away in daylight. I think people underestimate this.

So really, I think just a 10-20mW 532 green module (you will want green) through a normal line grating. Should be very easy and cheap to construct.

 

[Wooly]

To clarify a bit:

The line needs to be visible in sunlight on a grey surface. That would be the worst case scenario. It is important that it be bright enough so the operator can distinguish where the ends of the line are.

I know a <5mW red laser is visible as a dot in these conditions, but when I put a lens in front to create a line, the visibility diminishes and the line becomes difficult or impossible to see. I understand this is due to two factors: the color is harder to see to begin with, and the power of the laser is being diffused into a wider (fainter) beam.
So a green laser would be more visible, but how much power do I really need?

Remember, cost is important, as is battery life and power draw. It makes sense to me that I may need a more powerful, but cheaper, red laser or a less powerful, but more costly green. The tradeoff with the cheaper red may be reduced battery life-if it will work at all.
I'm just hoping someone has experience and can give me some insight as to where the boundaries of visibility are for these.
I know its a tough question to answer without having actually tried it out. I'm hoping to avoid having to buy a whole lot of "test" products that are not even close to what I need. I need to narrow it down.

Wooly

 

[InfinitusEquitas]

I have yet to find a laser that produces a visible beam (Line?) in bright sun light. \

If you by line you mean a beam, there is just no good way to do it. Even if you could, the use of a laser with sufficient power would mean having to use goggles, which kind of negates what you're trying to do in the first place.

As far as the dot is concerned, a 5mW green laser should more than suffice for most conditions.

 

[Ash]

You will need a 50mW 532nm laser and a line-generating lens.
Laser:
Green laser module 50mW For custom build or lab [OLGLM50] - $26.99 : Welcome to O-Like.com, Your source for laser products
Lens:
line and cross line generator lens [OL-L-8mm] - $3.00 : Welcome to O-Like.com, Your source for laser products
If you plan on running it for longer than ~10seconds at a time, you will also need a heatsink:
Lab style heatsink for 12mm laser modules [M0020] - $20.99 : Modwerx Shop
You can power it with a +300mA 3v AC adapter:
GE AV23636 Universal AC Adapters (500 mAh), Black, 6 Detachable Plugs, Converts 110V AC to 3V DC, 4.5V DC, 6V DC, 7.5V DC, 9V DC or 12V DC, Input Voltage 110V AC, 220V AC, Frequency 50Hz, 60Hz, Output Voltage Range 3V DC to 12V DC, UL Listed, UPC Cod

 

[chipdouglas]

i don't think he means a line beam in the day. i read it as a line on the object. which is totally doable.

michael.

 

[Wooly]

i don't think he means a line beam in the day. i read it as a line on the object. which is totally doable.

michael.

Yes, this is what I mean. I want the line to appear on the object at which the laser is pointed. I want a line to appear, not a dot.


Wooly

 

[InfinitusEquitas]

^^^Line ON an object, absolutely, I read it as a beam... Insomnia catching up to me:tired:

 

[chipdouglas]

OP, use what ash posted in post 7 then.


michael