Smoothing 3D prints with acetone and without patent violations

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36 Responses to “Smoothing 3D prints with acetone and without patent violations”

  1. Grahamers2002 says:

    DIY production and a way to get stoned, too?  I am in!

  2. OldBrownSquirrel says:

    Yes, but how does it work with the Stanford bunny?

  3. JustAdComics says:

    I hope they patent the process, if only to make sure no one else patents it and expects royalties from the use of the method. Very cool and clever on their part!

    • Joe Vanegas says:

      By publishing as they have it is now prior art and not patentable by others. It would be especially helpful if they mentioned a few variations that they find obvious to try next. Such statements would make it difficult to patent the variations because they are explicitly “obvious to one skilled in the art.”

    • mtdna says:

      As the Wired article says, they didn’t invent it. The guys say this is their refinement of the technique, to make it simple for everyone to use. They also didn’t even do that: Compare their ridiculous setup with this guy’s: http://solidoodletips.wordpress.com/2012/11/10/presto-part-finisher/

  4. Todd Miller says:

    Nice job, but I wonder if the process is hazardous or creates noxious fumes?

    • Mark Dow says:

      It’s always worth looking up the Material Safety Data Sheet (MSDS) and understanding it. For acetone:

      http://www.sciencelab.com/msds.php?msdsId=9927062

      Here’s the relevant portion for acetone fumes:

      VAPOR (LC50): Acute: 50100 mg/m 8 hours [Rat]. 44000 mg/m 4 hours [Mouse].

      These are the vapor levels and exposure times that are likely to cause acute harm (like death) in humans, as well as rats and mice. There is more about potential chronic health effects.

      Low, and occasional higher, vapor levels are tolerated in many manufacturing and nail polish environments.

      • AnthonyC says:

        Also: The flash point of acetone is very low, so if you’re intentionally vaporizing it, be careful about sparks or static electricity

        • Warren_Terra says:

          This was my snap reaction. It’s quite possible to do this safely, but I really don’t want some less careful, less informed hobbyist – possibly in my apartment building – vaporizing acetone in a closed space, with a convenient heat source and everything.

        • Boundegar says:

          But then if goons from a rival 3D print gang bust into your lab and demand the recipe for your cook, you can just throw that hot acetone in their faces and run off in your underpants.

    • Glippiglop says:

      Pure acetone is toxic to living cells, although exposure to skin (or finger nails) is not usually a cause for concern if washed off.

      Vaporized acetone would be extremely harmful if it enters the lungs.  In the past I’ve put on a gas mask before being exposed to it (usually when cleaning air brushes).

  5. Fuck yeah, racing down to the patent office right now to patent the fuck out of that shit! I got my running shoes on, just try and catch me!

  6. That’s kind of like antialiasing something by blurring it. I have an idea. I wonder if it’s a new idea or not. Has anyone 3D printed in material that shrinks on heating, like a toilet bowl or a tiki mug does during its manufacturing process? Then the steps would be a lot smaller after the object shrinks, sort of like antialiasing jaggy b+w text by re-sampling while reducing it in size.

    Although it’s probably not feasible. You’d probably need a 2:1 scale change at minimum before the advantages would start to be worth it. 4:1 even better, and even less likely. You’d need to be able to print something like a 3D Shrinky-Dink

    • mccrum says:

      When the end heats to extrude the plastic, would that make it a lot smaller from the get go?  Then as it cools it enlarges?

      I’m confused.

      • I’m saying make something 20 inches tall with 1 mm steps in the surface with the intention of shrinking it to a final size of 2 inches tall and the steps in the surface will be 0.1 mm. The problem is there is not really a process for massively and accurately shrinking things, so it’s really not feasible — although certain ceramic things, like toilet seats, are made oversized because they shrink maybe 20% when fired.

    • AnthonyC says:

      abs contracts on cooling- just a few % though. Anything with a really big thermal expansion coefficient would probably wreak havoc with precision unless you had excellent temperature control during deposition

  7. Xanthomonas says:

    Interesting approach but this is not a very safe method in current form. Solvents should never be heated on a hot plate and certainly not in a sealed container. In addition the container in the image does not look like it is heat resistant glass. Fortunately acetone vapor is not easy to ignite but but this is still quite risky especially if there are any open flames in the workspace.

    • dculberson says:

       It doesn’t look like they sealed the container.  That’s why it was important that the acetone fumes are heavier than air – they push the air out of the unsealed container but enough to fill the container remains behind since it won’t float up out of it.

      You do still need to be careful heating a solvent, and please don’t inhale it.

  8. for_SCIENCE says:

    Still might not be the best for bearing/bushing and the like. Sure, you get a smooth surface, but this process will still play hell with your tolerances.

    • Ray Perkins says:

       Isn’t this really a hardware version of a low-pass filter? Which reduces mechanical “noise” at the cost of precision. If over-used, the result would be just a blob.

  9. Kimmo says:

    Damn, that’s clever.

  10. Off White says:

    Is it just me, or is the end product just a little plastic animal? I mean, 3d printing is cool and all, but I haven’t noticed a lack of cheap plastic crap in the world.

    • AnthonyC says:

      Yes, its a demonstration.

      You can also do things like 3D print gear assemblies in one step that would be unassemblable if made in multiple pieces.

      And plastic crap is cheap because its mass produced. If you happen to be an engineer, making that first prototype of a part through non-3d-printing means is quite expensive. And custom goods are a lot costlier than mass produced kinds – but not with a 3d printer.

      • bobtato says:

        This technique wouldn’t be useful for assemblies printed all in one, though– the parts would stick together.
        What it would be extremely useful for is when you want to cast from 3D prints.  If this technique can work as well as the pictures suggest, then it opens up a whole range of possibilities.  I’d love to try casting lenses at home, for example…

    • mtdna says:

      Well, there’s this: http://www.engadget.com/2012/08/08/3d-printed-magic-arms-give-a-little-girl-use-of-her-limbs/

      Another cool thing you can do is print out little trolls, to give out to, you know… trolls.

  11. This technique has been patented and commercialized by Stratasys. I suspect the patent is weak, because it’s really just a variant of vapor-phase degreasing… which is a century old.

  12. Art says:

    Very impressive results! But I do have grave reservations about the home-based, DIY person working with heat and acetone.

    Way too much could go wrong. It sounds like a prescription for disaster.

  13. Brandon Barbee says:

    Vapor deburring isn’t new, but it is neat. I know of a company in Tennessee that does it to remove machining marks on optically clear plastic. They buy clear blocks of plastic, then mill them to the shapes they want, then vapor debur them so they can use them as sight glasses. Neat stuff!

  14. Dlo Burns says:

    Wait, has anybody tried using a rock tumbler?

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