Silicone printing & spraying on 4 axis printer

Hi guys - apologies for cross-posting this, but it's relevant here on the paste extrusion page too!

I built a silicone printer which can spray thin layers of silicone onto a permeable form, stretch it by inflation, 3D scan the subsequent balloon and then 3D printing silicone over the surface of the inflated structure.
I've made a video of the process here :

https://www.youtube.com/watch?v=Qmuf_6h7Kl8




All the geometry is calculated in by a script i wrote in Grasshopper3d, which also produces my GCode. I then wrote a printer control software script in Processing. This allows me to control multiple micro controllers at once, including a RAMPS for coordinated movements.

Rather than using a volumetric pump for the silicone, i use a high viscosity spool valve, with material pressured from behind (at about 80psi) - my silicone has a super high viscosity.

I can control the shape of the inflation on the balloon a little too :




Hope it's of interest to you...

There's a little more info at fergalcoulter.eu

... could be interesting too printing complete hardening/solidifying materials like concrete/polymer-beton and then remove the baloon - but then the balloon has to be stiffer with a thicker, more rigid hull too, as the printed hull will be much heavier than with plastics ...

Edited 1 time(s). Last edit at 07/07/2015 03:12PM by VDX.

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Viktor
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Aufruf zum Projekt "Müll-freie Meere" - [reprap.org] -- Deutsche Facebook-Gruppe - [www.facebook.com]

Call for the project "garbage-free seas" - [reprap.org]

Yes, certainly it would work well for some ceramics at least. I'm actually going to have a play around with some tomorrow and see how it fares!
I'm a big fan of unfolds stuff - I'm sure they could have fun with this system!

The balloons i've been making (by spray) lately for experiment are around 400 microns thick before inflation, The material is a super soft silicone - Shore 00-30, and it can elongate by 900% before breaking! its fun!
I have made balloons from much harder silicone (10A - 22A) by dip casting, while it took a lot more pressure to inflate, they certainly held up to a little weight....
Concrete would always be a tough one though!


this is a 00-30 one


and a shore 10A (admittedly still pretty soft!)

... can you spray different Shores as a 'sandwich' structure? - first the soft one to inflate, then the hard ones ... then they should stiffen in sum more than a single hull.

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Viktor
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Aufruf zum Projekt "Müll-freie Meere" - [reprap.org] -- Deutsche Facebook-Gruppe - [www.facebook.com]

Call for the project "garbage-free seas" - [reprap.org]

Most certainly sandwiching different shore hardnesses would work. It's slightly tricky to spray on top of an inflated balloon, as it tends to distort the substrate (due to the material exiting the nozzle at ~40psi)...which would leave the quite uneven layers...but with slumping, and the right movement during cure time, one could get really interesting shapes with fascinating properties!

... sounds like fun

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Viktor
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Aufruf zum Projekt "Müll-freie Meere" - [reprap.org] -- Deutsche Facebook-Gruppe - [www.facebook.com]

Call for the project "garbage-free seas" - [reprap.org]