Humongous 3D Printer Produces Boat And Challenges

We’ve seen some pretty big polymer 3D printers, but nothing quite as big as the University of Maine’s 3D printer with a 22,000 ft³  (623 m³) build volume. It holds the Guinness World Record for the largest polymer 3D printer, and with that size comes some interesting challenges and advantages.

You might have already seen the video of it printing an entire patrol boat hull in a single piece, and would have noticed how it printed at a 45° angle. Due to the sheer weight and thermal mass of the print bead, it cannot bridge more than an inch, since it’ll just sag. A 45° overhang angle is about all it can manage, but since the layers can be tilted at that angle, it ends up being able to print horizontal roofs with no support. A 10 mm nozzle is used and the extruded line ends up being 12.5 mm in diameter with a 5 mm layer height. The boat mentioned above was printed with carbon ABS, but it can reportedly use almost any thermoplastic. It looks like the extruder is a screw extruder from an injection moulding machine, and is likely fed with pellets, which is a lot more practical than filament at this scale. Check out the video below by [Paul Bussiere] who works in the Advanced Structures & Composites Center at the University. He also does a very interesting interview with his boss, [James M. Anderson].

The 45° layer angle is very similar to how some infinite build volume 3D printers work. For something more within the reach of the average hacker, check out the tool changing Jubilee.

 

27 thoughts on “Humongous 3D Printer Produces Boat And Challenges

    1. If it was a 100% educational project they probably would have, but this sucker is backed by the military. So picture the demonstration of printing benchy and reaction of the people who are footing the bill thinking “They are not taking this seriously at all, we need to migrate this project to a different university right now”.

    1. I believe there are ways, I’ve seen something like it before at least. If your printer supports dynamic bed leveling you might be able to spoof it into thinking it has a bed at a 45% incline, but i kind of doubt that system supports such an extreme deformation. No idea why it isn’t more prevalent; guess at normal nozzle sizes the weight of the line doesn’t necessitate it really. Wonder what FDM printing would be like in microgravity?

      1. Bed leveling simply deforms the piece by making the first layers at an angle and then (if you specify it with fade height) gradually removes it. the result is a piece with the lower layer deformed as if you had heated it and squished a corner

        Once I printed a small box and didn’t realize my bed was tilted 5mm lower on the front than the back, until it finished the print… looked funny honestly. the layers were all squished at the front as if I had used Adaptive Layers, and it made me go check…

    2. well, maybe you don’t use it… Me neither, but it’s a known technique to improve quality or toughness when you need to print a piece vertically. You just rotate the model 45° and enable supports.

      my printer struggles with simple 45° overhangs even with some pretty hardcore cooling so I won’t be trying it anytime soon

  1. In fiberglass boat construction, there are layers of glass fabric (and sometimes carbon or kevlar fabrics) that are placed as the hull is laid up to provide strength and rigidity. I don’t see how simply 3-D printing with a polymer could match the strength to weight ratio of a fiberglass hull.

    I’d love to hear back how strong and practical that printed hull turned out to be.

    1. You’ll notice they didn’t use the full 60ft printable length. Rule of thumbish, you can screw around with boat design below about 30ft and not get into too much trouble, above that the forces start getting significant and you need a naval architect. You’ll also notice that it’s basically double skinned with bulkheads and a central keel/rib between skins.

      1. Under-30 ft boats still hit docks, beaches or containers, have internal stresses from engines and loading, or get tossed around in storms. I don’t know of any boat near that size that is made from simply molding or shaping a similar material.

    2. Agreed it would be nice to see it tested to destruction, along with talk of its weight etc. I would think it might be rather comparable to fiberglass for practical use (once you figure out all the quirks of designing with a new process). With how much plastic is being pumped out I don’t expect the layer lines to be as much of a weakness as in a standard sized FDM – you are probably going to get a print performing almost as well as the base material is capable of. And as standard sized FDM prints show you can get a much lighter structure with 3d printing without loosing much strength over a solid block of the same material in the right situations. (even possible to have stronger per weight prints than the stock material – as FDM lets you create a structure designed to take the load only in the needed directions).

      Even if it can’t match fiberglass yet I think its got great merit as a technique/tool for making a ‘fiberglass’ boats. Any complex shape you want in the boat hull for whatever reason can be printed and the outer hull skimmed with fiberglass – both to smooth out the printing layer lines for better hydrodynamics and to add strength.
      Could allow for some fast and effective iterative designs to get that absolute optimal for whatever use case, and as with normal scale 3d printing its great for small production runs.

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