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Cutting flexible stencil material for etching

I just receive my kit Monday and assembled it last night. I seem to have it up and running with the test pattern and some random screwing around. Now I want to cut flexible material that I can use for blast etching onto metal, or chemical etching onto glass. I'm wondering if anyone else has done so already and what material people would recommend.

Comments

  • Ok, so I experimented a bit tonight. I am running the default power levels and currently have the G2 lens installed not the other one.

    I am trying to cut light grey silicone rubber mat, 1/32 thick. I started at 5mm/sec, 100% power, 2 passes, cutting a 20mm radius circle. I started adding passes, and at 5 it didn't seem like it did any more than 4, so I started lowering the speed further. At 2mm/sec with 4 passes, it nearly cuts through - close enough that some pulling or stretching will separate the parts. The groove cut by the laser is noticeably wider when run this slowly though.
  • Hi Justin,

    Interesting to try cutting silicon. We haven't ever tried this. We actually sometimes use a silicon mat to protect our base plate because it can withstand high temps.

    I would recommend running the same tests using the 3 Element Glass lens. You will be able to focus it to a finer point than the G2 lens and hence concentrate the power more.

    You are correct that multiple passes will ultimately give diminishing returns. We usually limit the number of passes to 3. Any more than this and we try to find a different solution.

    I wonder what the result of adding a very thin layer of black paint to the grey mat. If it can be removed easily afterwards, it may help concentrate more laser poser as opposed to letting some pass through the thin silicon.
  • Ok, I finally had time to try again. I swapped in the 3 Element Glass lens and focused it as best I could, then did a few more runs. It looks like at 100% power and 2mm a second, I get good separation after three passes, with a small amount of mechanical effort causing the rubber to separate relatively cleanly (not perfectly but it is fairly decent). I will probably flip the dip switches to get power up higher, and I may have another go at focusing the laser.

    One problem I did run into this time that I did not have in previous attempts was that there was apparently enough heating to cause the silicone rubber sheet to flex upwards. I'm not sure if it was from air being heated beneath it or something else, but that caused the sheet to get dragged by the shroud on two of my attempts. When that happened I actually got some decent burn through on a single pass, so it may be that very low speed or a bit more power will do the job.
  • This is great info Justin.

    If you are in an experimenting mood then some users have suggested placing a piece of clean clear glass over your material and engrave through the glass.

    The glass will allow the laser to pass directly through it and hold your material flat at the same time.

    Be extremely cautious with this process.
  • Hey Darkly Team

    After i saw that you suggest a glass over the cutting material, I just decided to give it a try. I tried to cut thick cardboard which needs aroung 15 passes at 15mm/s and 100% power to cut through if it is not covered.

    when I tried it with the glass the cardboard was not cut through but the glass was etched. Did not think this would be possible. Is this supposed to happen?

    Dominic
  • Very interesting.

    I wonder if it is because of the optical quality of the glass. It is interesting that the laser doesn't affect clear acrylic.

    I know people have been engraving onto the back of mirrors, but not directly through clear glass.

    What is the quality of etching on the glass?

    This well definitely need some more investigation.

    Thanks for the feedback.

  • From my observations, I am thinking that the etching that occurs on the underside of the glass is caused by the heat focused directly against its surface made possible by the cardboard,

    I have come to this conclusion as it seems that any separation between the glass and cardboard negates this effect.

    It is defiantly an area that warrants further investigation.
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