Sounds like some kind of sacrificial layer is a good way to go.
I sent you an approximate GF bed sized sample (which was wicked hard to fold into an envelope! it is so floppy and soft it was like trying to put jello in an envelope!) so you should be able to make some reasonable attempts. I can send you a heart valve approximate cut file to see what a complex cut would beā¦
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Wonder if you could make a punch/die from acrylic??? Wouldnāt have the longevity of a steel rule but might work for a few punches.
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Stiffen the fabric first. You could try liquid starch. Smooth out flat, let dry completely.
Cut or laser. (Iād use a digital cutter.)
Wash out the starch.
We had to stiffen fabrics for cutting with a tiny blade in a digital cutter. Things that work best are dilute Mod Podge or Elmerās glue brushed on and dried, starch (so-so), and iron-on stabilizers. (Interfacing.)
Not sure how well those would work with silicone though - so you might want to try just plain old potato starch first.
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That should be plenty if there is an easy way to do it.
Here is a reasonable test file for the types of things (on the small side) I need to cutout.
We also need to make nice long straight cuts which would be awesome only for repeatability.
heart valve tests.ai (58.6 KB)
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Gracias for that! Iām now advertising on Craigslist for reduced cost heart valve replacements.
Gotta go! Got my first inquiry!
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If acrylic dies made with the glowforge like @tom suggested would work, a machine like this might be the answer?
Cutting the powermesh directly on the glowforge might be wonky if the air-assist wants to lift up any of those tiny āparachute stringsā in the processā¦
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SCISSORS?!? as a lefty I hate scissors.
use a shear(like a paper cutter) or an exacto/utility knife, would have to be very sharp.
or even a single sided razor blade. you could lay the material out flat and then just press down. Oh wait. a fabric cutter! kind of like a pizza cutter. they come with a special surface to work on. sewing shop would have that.
that would be the fastest I think.
though low tech.
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Okay, the mesh was waiting on me when I got home from work and I was anxious to give this a try.
First I wanted to get a feel for this stuff so I tried cutting it with scissors. Wow, that sucks.
Then I wanted to try it alone but there was no way this stuff will just lay there so I put painters tape on the bottom side and tried it. Nasty, formed a chard goo.
Next, I encased both sides in painters tape and went way down in power and way up in speed.
When I got to 1% and 150 I was getting pretty good cuts, at 1% and 170 we are no longer getting consistent cutting.
I never was able to get the fine details of the tentacles for two reasons. first, the Glowforge is not dynamically controlling the power at this point so anyplace the head lingers gets more heat than straight cuts, and two, this is woven not a solid membrane.
So, circles, squares, strips, pretty much any shape is doable other than super thin things and not a lot of head reversing. As you can see in the photos the scalloped valve cut great it is just the tentacles on the first one that messes up. I think tomorrow I will do some files of my own to see what the lower limit is, from what I can see the tentacles would work if they were around twice as thick.
Juck!
This is better
Not bad after carfuly removing from tape. Just canāt do microfine tenticals.
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Those gentacles tentacles look to be hardly any larger than the holes in the mesh. Seems hard to imagine a feature that size would be possible in that material, regardless of how itās being cut.
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Right, tomorrow I will do some files of my own to see what the lower limit is. Even though the tentacles are coming off I am calling this mostly a success.
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Iād say itās a success as well. The larger features look pretty crisp to me.
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The other interesting question is for that specific model (the heart valve leaflet) we actually skim it with silicone which we could do before cutting, which may make it way easier to work with.
Even that would be a huge help, the blood vessel is a half inch strip like 20 inches long, which as you noticed is almost impossible with scissors!
This is an awesome start!
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Doesnāt it feel good to be assisting medical research? Great job!
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Silicone doesnāt cut well when its thick, but may have better luck if itās a thin coatā¦that might be the right carrier to keep it stable enough to cutā¦
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Yeah, it is super thin (like 0.5mm or something). Itās just enough to fill the power mesh holes.
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very interesting topic. We cut fabric with a CNC knife cutter using a vacuum. There is a special paper placed under the fabric. This paper has holes in it for the vacuum to pass through. Then the fabric is stacked up on top of this. A thin plastic is placed on top of the stack and the vacuum sucks the entire thing down tight.
That being said, there is no way this method would cut the fine detail that you are trying to achieve here.
Another option to consider might be waterjet. Here is a link just to show some possibilities.
http://www.specialisedengineering.co.uk/services-and-products/cnc-waterjet-and-knife-cut-gaskets-and-profiles/
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I canāt break a purchase of a Wazer to the wife until the GF has been in house for a while (although that may be easier than the future Tormach!!). My kids look at me like Iām a heroin addict (mind you I buy 3D printing filament on 2Kg spools since I print too much on a daily basis to use 1kg or 750g spools). Of course I was commenting to my son about someone wanting to engrave paper, and he whipped out āoh, I use 5/200 as a settingā (head spins - kid knows laser cutter settings off the top of his head?) so pretty sure my son canāt really complain about my habits.
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Where do you get your 2kg spools from, they seem to have gone out of fashion? I used to be able to buy 10kg spools but that was a long time ago.