So a friend wants a laser....

[GBD]

Ive been showing a friend of mine some of my builds, and now he wants a 445nm. From what he told me, he would be very interested in mostly burning power, so I suppose the high powered nature of 445nm will provide the visability and burn needed. Since he was impressed with just 500mw smoking some stuff, I think that this power level will suffice. (Don't really matter to me on the power, I can set it to whatever I choose).

Now, I really didn't start this thread just to hear the usuall safety logorrhea regarding high powered lasers, "newbs" and saftey goggles. I have thoroughly warned him of the power and the concenquences.

Now what I wonder, seeing 445nm is the cheapest for me to build and achive decent burning power, is kinda to what output power to set it at.. Im personally thinking to the 200mw-500mw range, for two reasons.

1st. 500mw is plenty to burn once focused.
2nd. Lower power, longer duty cycle. This guy doesn't have the greatest knowledge on electronics, so I would like for this build to be at 100% use till the battery died. As not risk overheat failiure and other things.

So my two questions are, what is a good power level to set it at for this situation? 200mw? 500mw?
And for the low power, Im thinking to just stick to alkaline based batteries rather then our lithiums, seems safer to me to do so as high power isn't really needed and lithiums do present a hazard while charging unattended if recieved a bad or defective battery.

Thoughts?

 

[InfinitusEquitas]

I think if you doubt your friends ability to handle lithium batteries... you shouldn't give him a laser:undecided:

In terms of power, I find ~350mW to be more or less perfect for 445nm.

Duty cycle depends on heatsink more than anything... what kind of a host were you thinking about?

 

[bennett326]

one thing i would at least use nimh rechargeable batteries so he doesn't spend a fortune on primarys

 

[GBD]

EDIT: posted before last responce... I like the Nimh idea.

Well, its not so much that I doubt his ability to use lithiums... its I myself don't want to take the risk to give some defective battery unknownigly and have it go kaboom while charging at his place. That already happened once to me to what I thought was a perfectly good battery and charger.

Host wise.. I didn't really deside yet, I half was leaning to machine something along the lines of 7" X 1.5" or so. So plenty of battery room and heatsinking.

 

[bennett326]

i think 3 sub-c sized nimh would work great for a boost driver and your so luck you can machine whatever you want.

good luck wit your project

 

[InfinitusEquitas]

^^^But that's like saying, I want to give this friend of mine a gun, but I'm afraid to give him real bullets.

For the power you're looking at, and since host size is not an issue, I guess it's not really a problem, but definitely go with rechargeables.

Personally imho 300-400mW is perfect for what you want. Also with that power level, you can force him to buy cheaper goggles and more or less get away with it. I have 3 goggles I really would not trust for 1W+ but for 400mW they do fine.

 

[GBD]

Sounds good to me, I think that is the path that I will take.

I rarely use safety goggles unless im aligning or focusing something where its hard to work with a big blind of light... so I can spare a few cheap goggles. They work fine for this power too.

With his budget anyways, im not too concerned about additional expenses for safety gear.
I suppose Ill sleep on it to see if I actually want to build him one..not sure about it still. as concerning as that might sound towards your gun analogy infinitus

 

[bennett326]

Sounds good to me, I think that is the path that I will take.

I rarely use safety goggles unless im aligning or focusing something where its hard to work with a big blind of light... so I can spare a few cheap goggles. They work fine for this power too.

With his budget anyways, im not too concerned about additional expenses for safety gear.
I suppose Ill sleep on it to see if I actually want to build him one..not sure about it still. as concerning as that might sound towards your gun analogy infinitus

please post pics when your done i want to see how your custom host turns out

 

[InfinitusEquitas]

Sounds good to me, I think that is the path that I will take.

I rarely use safety goggles unless im aligning or focusing something where its hard to work with a big blind of light... so I can spare a few cheap goggles. They work fine for this power too.

With his budget anyways, im not too concerned about additional expenses for safety gear.
I suppose Ill sleep on it to see if I actually want to build him one..not sure about it still. as concerning as that might sound towards your gun analogy infinitus

I think 99% of the time I'm actually using goggles it to LPM the lasers, or to set them focused to infinity. Other times I'm just very mindful of the beam/dot. The other 1% is when some bug annoys me:eg:

Sleep on it. I mean I know I have some friends, I would NOT allow to handle a laser... even though they are mostly same age or older than me (I'm 26).

 

[GBD]

please post pics when your done i want to see how your custom host turns out

Assuming I deside to do this, I will most likely make it not too far off this one:
offcoarse, running 350mw rather then 700mw.

http://laserpointerforums.com/f65/my-pocket-custom-700mw-62570.html

Likewise here with the age infinitus (well, except that im 18 now, not 26).. But age is irrelevant I suppose. its mostly personal responsibility that concerns me.

 

[bennett326]

Assuming I deside to do this, I will most likely make it not too far off this one:
offcoarse, running 350mw rather then 700mw.

http://laserpointerforums.com/f65/my-pocket-custom-700mw-62570.html

Likewise here with the age infinitus (well, except that im 18 now, not 26).. But age is irrelevant I suppose. its mostly personal responsibility that concerns me.

nice job i had never seen that before (i joined in may) :drool:

 

[GBD]

Cheers.

Well, thanks guys, I will sleep on it and if I do it, I will go with the Nimh and 350mw approach.
I woulda just gave him that one... if the battery tube could hold any known Nimhs for that voltage and current requirements and I didn't epoxy the thing shut with a 700mw module.

 

[Isoleucine]

Like other people said in the replies. Stick with under 400 or maybe even 300mW. Provides a decent amount of safety. Speculative reflections are not safe... especially with blue light.