I just got a 3D printer and tried using multipipe for the first time, trying to print some of the stuff I’ve seen on the forum. I remembered a prior thread from a couple years ago, when I asked for help with visualizing the overlaps of 2D curves that cross themselves. @inno 's idea to simply ramp the curve along its length in Z turned out not only to work for what I wanted, but also looked like the way I imagined 3D printers work (which I now understand is “vase mode”).
Fast forward, I decided to try it - and quickly learned that vase mode is only one very tiny layer thick, which isn’t really practical. But then I thought of multipipe to thicken the curve, and
it just worked! (not at all my usual experience)
After a bunch more successful tries I’ve run into a problem where multipipe sometimes creates spikes at sharp corners (but not always). I’ve tried to track it down but haven’t found the solution (green is the ramped curve):
I did try playing with KinkAngle, but no luck. I suspect I’m making a very newb mistake - any suggestions welcome!
multipipe spikes1.gh (166.8 KB)
I think it might be where you have very short curves or lines and the node at the ends engulfs the line causing the multipipe component to fail. Or where lines meet at very shallow angles.
I posted a similar topic here
@DanielPiker has posted a good explanation of the Multipipe Inputs somewhere but I can’t find it.
Thanks Martyn! I missed your prior posting when I searched - but @DanielPiker 's answer makes it clear to me now. Armed with new understanding, I tried a few ways to fix my curve so it didn’t have super sharp corners using smoothing components, and it improved things (at a cost of introducing a lot more points / time):
But I couldn’t fix it completely. Not hugely important to for me to nail this (I’m probably done printing ramped 2D spiral paths), but I certainly learned at least one thing to avoid when using multipipe!
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I’ve experimented a bit with vase mode. It’s really interesting. Have you seen the Sierpinski pyramid prints on printables?
https://www.printables.com/model/432767-octahedroflake-a-higher-dimensional-analog-of-the-
I’ve tried to find a nice way to use GH to design shapes where each layer is an incremental change from the layer below but it’s hard to do. I had some fun with this… https://discourse.mcneel.com/t/3d-printing-vase-mode-for-fractals/159007
and it led me to try this…
https://discourse.mcneel.com/t/vase-mode-with-kangaroo-gradual-crumpling-of-curve-sections-for-a-loft/160167
Thanks for the excellent links, Martyn! I’m particularly interested in printing small lamp shades, and some of these might work well. BTW, I did see your prior posting about vase mode, and immediately tried it. (Sadly, it leaked because I didn’t know how to make a good bottom 
)
And though I don’t think it has much practical value (other than teaching me more about GH and printing), I couldn’t resist trying to fix my spiky multipipes. Didn’t get a universal solution, but did manage to de-fang the original posted shape.
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Looks good! Are you printing in PETG or a clear PLA or something else?
Thanks. My first experience with 3D printing was seeing RepRaps at the first Maker Faire in 2006. Fed by all the hype, I remained skeptical until just a couple years ago, when the younger folk I work with showed me how useful it is for prototyping. Now I’m hooked! Using PETG since it’s strong enough for our prototypes, and I have staff nearby with loads of experience to help me when I get hopelessly lost with settings / supports/ stringies… GH has already proved extremely useful in designing cut-files for my laser and CNC router. Looking forward to using it for printing parts as well.
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Ha! I bought one of those repraps and let’s just say it was a learning experience!
Fast forward to today and I bought a Bambu Labs P1P and it’s a totally different league!
I’ve had the use of a £250k Stratasys multijet fusion printer at a workplace once which was obviously good but the Bambu has been amazing for the price.
It printed this…
How cool is that!
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