Laser type/size

Just trying to determine the feasibility of creating small holes, < 1mm (.o4 inch), in very thin material using a readily available laser.

The ideal material would be household quality aluminium foil (or the thicker heavy duty variety) but the reflectivity of this material would probably be a problem for the laser (could it be coated black by something?), but anything that was completely opaque to light and would give a smooth finish around the hole would do.

Being able to accurately position the hole would also be essential.

Round holes would do, but square holes (i.e. the laser would need to burn very fine lines) would be even better.

Anyone have any experience/ideas in this area?

I am curious to the need / use of this project. I am sure there are more simple ways to perforate tin foil.

SN

SuperNova said:

I am curious to the need / use of this project.  I am sure there are more simple ways to perforate tin foil.

SN

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I'm investigating the use of lasers for making high quality Nipkow disks. There are, as you say, other ways of doing that but none of them are particularly accurate. The most common ways are drill bits or punches. Drill bits aren't too bad but are a problem to obtain in very small sizes < .3mm and they can only make round holes (ok, but not optimum) and I haven't seen anyone able to drill them accurately positioned (a CNC machine helps here but the bits still tend to wander). Punches can be made any shape but are difficult to manufacture (at least accurately) and they tend to leave jagged edges at the rear of the hole unless you make a die for the punch and I would not even know where to start doing that.

The best disks are made by professional laser cutting but that is a very expensive option.

Being able to accurately perforate thin material oneself opens up many avenues for experimentation.

Given the underwhelming response to this question I guess I can say that it probably isn't feasible to do this, however I thought I would just try once more so the post doesn't get lost altogether, can anyone say that this is definitely NOT feasible? At least that would save me from doing any further research/experimentation in this area...

well im no laser expert but i can say it can be done. you can cut steel with high power lasers so you can cut aluminum with the right laser. i dont know what kinda power you would need but i can guess its going to cost alot.

Another way to do this (including arbitrarily shaped holes) is microEDM or micro electrical discharge machining. You can also do it with a laser, you have to image the shape you want onto the material and hit it with a pulse, it is not really super easy without a pulsed laser that allows you to either control the energy or it is low energy and you use many pulses (1000s or more). Qswitched YAG lasers are used for this a lot, it is really easy to just shoot it a bunch of times until you remove the material you need to, I dont know if it is possible to do what you are talking about without using a pulsed laser, CW lasers just melt things, they arent very useful for high precision things.


Also I just found this link you might find useful. page over to get to the interesting stuff.

http://www.mrl.columbia.edu/ntm/pg2.html

Ethator said:

well im no laser expert but i can say it can be done. you can cut steel with high power lasers so you can  cut aluminum with the right laser. i dont know what kinda power you would need but i can guess its going to cost alot.

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Ah, indeed. I should have made it clear that by feasible I meant economically as well as technically. It would need to cost less than sending out to a laser cutting firm.

The basic concept is that I want to make very small holes in very thin material and thus am hoping that a low power (and hence cheap!) laser can cut it - so to speak.

The issues would be:

Can the low power laser be readily focused (if necessary) to a sub-millimeter size? - obviously the smaller the better.
Given that it can does this concentrate the power enough to burn the material effectively?
Can the beam be accurately positioned? (I'm actually prepared to say that I could organise that given the other two criteria but there may be issues others have come across that I am not aware of).

likewhat said:

Another way to do this (including arbitrarily shaped holes) is microEDM or micro electrical discharge machining. You can also do it with a laser, you have to image the shape you want onto the material and hit it with a pulse, it is not really super easy without a pulsed laser that allows you to either control the energy or it is low energy and you use many pulses (1000s or more). Qswitched YAG lasers are used for this a lot, it is really easy to just shoot it a bunch of times until you remove the material you need to, I dont know if it is possible to do what you are talking about without using a pulsed laser, CW lasers just melt things, they arent very useful for high precision things.


Also I just found this link you might find useful. page over  to get to the interesting stuff.

<link>

Click to expand...

Great info and link, thanks.