Lost PLA Casting Brings out the Beauty of Macromolecules

Biochemistry texts are loaded with images of the proteins, nucleic acids, and other biopolymers that make up life. Depictions of the 3D structure of macromolecules based on crystallography and models of their most favorable thermodynamic conformations are important tools. And some are just plain beautiful, which is why artist [Mike Tyka] has taken to using lost-PLA casting to create sculptures of macromolecules from bronze, copper, and glass.

We normally don’t cover strictly artistic projects here at Hackaday, although we do make exceptions, such as when the art makes a commentary on technology’s place in society. In [Mike]’s case, not only is his art beautiful and dripping with nerd street cred, but his techniques can be translated to other less artsy projects.

kcsa_5_bigFor “Tears”, his sculpture of the enzyme lysozyme shown in the banner image, [Mike] started with crystallographic data that pinpoints every peptide residue in the protein. A model is created for the 3D printer, with careful attention paid to how the finished print can be split apart to allow casting. Clear PLA filament is used for the positive because it burns out of the mold better than colored plastic. The prints are solvent smoothed, sprues and air vents added, and the positive is coated with a plaster mix appropriate for the sculpture medium before the plastic is melted out and the mold is ready for casting.

[Mike]’s sculpture page is well worth a look even if you have no interest in macromolecules or casting techniques. And if you ever think you’ll want to start lost-PLA casting, be sure to look over his build logs for plenty of tips and tricks. “Tears” is executed in bronze and glass, and [Mike]’s description is full of advice on how to handle casting such vastly different media.

Thanks to [Dave Z.] for the tip.

6 thoughts on “Lost PLA Casting Brings out the Beauty of Macromolecules

  1. I have yet to try this, I tried casting a PLA print like lost foam, but even molten aluminum can’t burn the PLA out fast enough. But I really want to try lost PLA casting. I just don’t have a kiln I could leave it in for many hours.

  2. We all know that 3D printing is NOT for finished goods (It’s not, stop kidding yourself). But is IS fantastic for prototyping, and making molds.

    Why are there not many mods to print with wax? That seems like a much easier method than burning PLA out if you are using your printer to make a mold.

    1. I think the primary reason is that waxes tend to go directly from solid to liquid without a significant plastic state, so the wax would run rather than keep its shape leaving the nozzle.

      There IS a hybrid of paraffin and polyethylene (polythene) or polypropylene known as “machining wax”, which does have a plastic state; this might be ideal for lost-wax casting.

      It seems to me that plastics such as PE and PP would also be great for FDM printing. I’ve done a lot of plastic welding using slivers of PP for the welding rod, and it works great there – joints are as strong as the original plastic. This used to be a big thing for fabrication of one-off or low-volume items such as liquid tanks. Much nicer to work with than PVC (no toxic fumes, no need to use solvents for joining parts). Anybody know why these plastics aren’t used in 3D printing? Or are they?

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out / Change )

Twitter picture

You are commenting using your Twitter account. Log Out / Change )

Facebook photo

You are commenting using your Facebook account. Log Out / Change )

Google+ photo

You are commenting using your Google+ account. Log Out / Change )

Connecting to %s