is there any metal my laser can cut?

[Devon Jones]

has anyone been able to cut any metal at all? if so what kind and how thick was it?

[Tim Bateson]

Tin/aluminum foil - does that count as a metal? :cool: Note: Dull side up.

[Devon Jones]

i figured that i could cut that tim. well there is this thing that my friend buys for weddings that he dj's and it runs him 100 a piece and if i could cut it i could make money and sell them cheaper then everyone out here. it is a super thin piece of mettal that has the bride and grooms name on it that you put into a light and it projects it onto a wall. it would take little to no time to make. the reason why it is metal is it has to be able to withstand the heat from the light for hours. any ideas would be great............

[Richard Rumancik]

You are talking about making gobos - they are usually stainless steel or brass and usually range in thickness from about .010" to .020". I don't think you can cut anything like this with the laser even with 120 watts.

Making gobos is something that I have looked at quite a bit and experimented with, but with a different approach. The idea is to use a resist of some sort and laser away the resist. Then use chemical etching techniques to etch the metal away to form the cutout. It may take a bit of R&D to perfect a technique. Rodne has written a few things about using ferric chloride to etch metal. There are other options.

If you are making a lot of the same thing, the laser may not be optimum tool as it may be cheaper to make a film positive/negative and use photoresist methods. But for one copy of a gobo, the laser could save a lot of steps and work well.

One of the challenges is finding a suitable resist that the laser will ablate away leaving a clean surface. Rodne implies that it doesn't exist. At the minimum, you need a surface that you can "clean up" to make it reactive to the chemical. If there is any residue, you will get uneven etching. I have tried many paints, lacquers, enamels, etc etc. for resists but have yet to find one that I could recommend.

It won't be quite so easy as dropping material in the laser and cutting the shape, but it may be possible to still make money if you can develop a good technique.

[Dan Hintz]

For more simple designs, I would suggest a vinyl cutter and some heavy-duty vinyl. Chemical etch as suggested previously.

[Rodne Gold]

Our local big laser guys have a min charge of $20...I use em a lot for metal cutting..they cut and supply the metal .. from what Ive had done , I recon a run of 100 Gobos would cost less than $2-3 to me.
At that price I wouldnt futz with a laser.
I did use paint on brass and then cleaned the ablated areas with handy andy and it worked a charm for shallow etching.
For your type etching , that is fall thru ,, on stainless , I would use nitric as the mordant.

Here's a good home based setup
http://www.prototrains.com/etch1/etch1.html

I used the vinyl cutter for less intricate stuff, as Dan suggested

[Richard Rumancik]

Well, the "going rate" is say $100 for a custom gobo; if Devon can do it for $80 or $90 he has the job. The customer only needs one, not 100. So Devon creates the artwork, and does it all in-house (somehow) and collects $80. Or he subcontracts the lasering for $20 and has $60 left. I suppose both work.

But I doubt if I could find someone to do the lasering for $20. Probably more like $50+ min. for a lot of shops. At that price, it doesn't work to subcontract anymore.

A lot of the laser shops are geared to making heavy sheet metal parts; they just don't have the skills or equipment to do fine laser work. (And if they can, they are probably in the gobo business themselves.) There are lots of laser shops around here, but I'd be hard pressed to find one that could cut a gobo. If you don't have excellent edge quality, the projected image will be poor.

Devon, the artwork can take a bit of time as you need to make "bridges" so shapes don't fall apart. So keep this in mind when estimating labor time. If doing text, the centers of some letters (A,B, D etc) will fall out so you need to add bridges to them. Takes a bit of artistic skill so it looks good. Also, if doing shapes, you can't have large areas unconnected, even if they don't actually fall out. The reason is that they will warp from the heat so you want to tie the shape together.

I still think it might be worth going after, if you have some time to do some R&D.

A lot of commercial etching like this would be done from both sides, as it is faster and gives a better edge. You might be able to do it from one side if the material is on the thinner side (.008-.010 perhaps.) Two sided etching would be more challenging to do, as you need accurate pattern registration from side to side.