Designing Sninges in Laser Cut Acrylic

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By Sean Michael Ragan
Posted 2011/12/08 @ 4:00 pm
Category 3D Printing, Workshop

I’ve been seeing this “zig-zag” living hinge technique all over the web since we covered snijlab’s apparent invention of the method six weeks ago. “Snijlab-style living hinges” is kind of a mouthful, and since it looks like the idea is here to stay, I humbly offer “sninges” as the obvious, handy portmanteau.

Anyway, we’ve covered designs using sninges a couple times, already, but so far I haven’t seen much detailed discussion. Enter Make: Projects user Kevin Gunn, who’s just published this handy guide describing his own experience, to date, with designing laser-cut sninges in 1/4″ acrylic. [Thanks, Kevin!]

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0 Responses to Designing Sninges in Laser Cut Acrylic

Anonymous on December 8th, 2011 at 5:19 pm said:

I’m not sure “invention” is the right word – this looks like the same technique that been used for years to make flexible sections in MEMS devices – but I haven’t seen it applied to macro-scale objects before. Neat!

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- Sean Michael Ragan on December 8th, 2011 at 6:36 pm said:
  
  Awwwww…..but…”sninges!”
  
  Yeah, ya’ll are prolly right. I didn’t know about the MEMS application. So now it’s not even an “apparent” invention. Oh well.
  
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  David C Dean on December 9th, 2011 at 1:35 am said:
  
  Hey, folks re-discover old ideas and apply them in new places all the time, right? I say they deserve some cleverness credit too.
  
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curt seeliger on December 8th, 2011 at 6:10 pm said:

This technique has been around well before MEMS and acrylic, having been used by indians of the Pacific Northwest Coast for some centuries now. The museum in Vancouver BC has an excellent collection which includes some bent wood boxes.

More recently, Fine Woodworking published an article on them back, I think, in June 1980. Kerfs are also used to allow bending of plywood around tight corners in houses, but only for a few decades.

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Ian Page-Echols on December 8th, 2011 at 11:49 pm said:

Thanks Curt! I knew I had seen some really old examples of this type of thing! Besides extremely old uses of this, there was a really cool MacBook sleeve type case a couple years ago in which the flap folded using something like this. I fully blame search engines for this type of article. There is no good way yet to look up something where you don’t know the name of a method, or protocol.

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Jiskar Schmitz on December 9th, 2011 at 5:20 am said:

Hey all, Jiskar from Snijlab here. Thanks for sharing, we love to see people working with this technique.

Just to clear up the discussion on who invented this: We found out by accident how easy you can make hinges when we were laser cutting springs. This wasn’t widely known in the DIY scene so we developed it into a strong hinge and presented some booklet designs on thingiverse just to show it. There are probably lots of other folks that made something similar and they deserve credits too.
The point is really not who invented this, the point is that it’s useful for others and therefore should be known!

And indeed, MEMS devices give a lot of inspiration. Try googling “compliant mechanism” for other cool laser cuttable mechanisms!

greetings from Rotterdam.

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- Sean Michael Ragan on December 9th, 2011 at 10:57 am said:
  
  Hey Jiskar! Lovely to hear from you. Thanks for reading, and thanks for taking the time to comment.
  
  I agree that the point is not so much who invented this, and will allow that *part* of the point is that it’s useful for others and should be widely known and celebrated. But the absolute, fundamental, most important point is this: Can we call it a “sninge?”
  
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Anonymous on December 9th, 2011 at 9:07 am said:

Or in plywood – architect Gregg Fleishman http://www.greggfleishman.com/furniture.html has been making chairs this way for a few decades. He also has some patents from The early 90s on some methods for making springs and bendable shapes by cutting patterns in thick solid material.

Elil Chissick has a similar idea with some fruit bowls that are cncd out of plywood then bent into form. See here – http://bit.ly/stypfb

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