Stencil without melt bead?

Hi There. I need to create a thin film cut that optimally does not have a left over melted bead where cut. I have been experimenting with multiple materials where .010-.015" is optimal. I have found that acetate, PET, mylar are recommended and have found the closest thing in thickness to my needs on amazon. https://www.amazon.com/dp/B09DLC3HTR It is unclear which type of material it is as it lists about 5 different, though I think they are all similar. This definitely cuts better edges than I was able to get with ABS and similar.

But I am still getting a small bead of melt on the finished edge which creates a small edge. I have experimented with some different speeds and power settings with the best being near to 9%, 10mm/s K40. Air assist at 15 PSI, material elevated and in beam focus. I’m guessing that by the nature of the laser melting the material that it will be hard to get a perfect (non-beaded) cut edge, though it seems acrylic has very clean edges when cut.

Wondering if you have any other suggestions in terms of any tother cut settings (maybe run higher power and run faster), different materials (maybe higher temp closer to acylic melt points?), anything else I might try? Thanks!

You might try using blue masking tape on both sides. I found that helps sometimes.

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I wonder if multiple fast passes would be better rather than one pass clear through? Maybe that would vaporize some of the material off of the surface while there’s still a back layer to keep it from sagging? No idea, just spitballing.

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What I usually do is to put the cut sheet on a flat surface and give it a few passes with fine sandpaper on both sides. This has the added advantage of matting the sheet, making it easier to see where the holes are.

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My wife creates stencils using thin materials for her art on a Cricut cutter.
It cuts a nice clean edge.
I originally bought the mid level machine to cut vinyl stickers but she uses it the most.
Now that I know the capabilities on the machine I would recommend going big and get the top version of the machine as it cuts thicker materials.

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If you don’t find an acceptable solution using the laser, @PaPaSteve brought up another option which reminded me that people have put those pivoting cutting blades(drag knife) onto 3D printers and CNC machines and used those to cut out designs as opposed to purchasing a new machine.

Maybe you could add a drag knife to your laser cutter. You’d need to add a servo or other mechanism to raise and lower the blade to move between holes.

example: DIY Vinyl Cutting Drag Knife for Desktop CNC | MCU on Eclipse

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Thanks for the tip. Yes we have a cricut here and, though I think it may be older. It does have the cleanest edges, but our model at least cannot handle small radius corners. I need near right angle corners with very small acceptable radius’.

Does anyone know if the more expensive models support tighter radius cuts? This article says .75" min radius which is wayyyy to big. https://help.cricut.com/hc/en-us/articles/360009557073-Cricut-Maker-Knife-Blade-FAQ

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awesome idea!

With the min radius issues I have for my application, I’m starting to look at standalone desktop CNC machine. Pretty amazing bang for buck on amazon - it appears. Anyone have any suggestions on CNC best bang for buck platforms. I’m fine with some amount of work required to get it running right - similar to the k40 setups.

Created a post here if that’s more appropriate to post there?

Cricut machine model we have is an Explorer 2
While it has a cutting “blade” it does not use the “knife blade” attachment … there is a difference.
The “knife blade” has a gear on the top of the holder where the “blade” does not.
“knife blade” is only available for the top model.
An example of what she makes.

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That’s not cutting radius. It just says if the interior pieces are smaller than that they might not be held by the adhesive and you might have to clear them with air or brush.

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Did you try 100% power at 10mm/s and use the pot to lower current to the 9% range you refer?

Sorry, didn’t notice the date… :face_with_spiral_eyes:

:smile_cat: