World’s Largest 3D-Printed Titanic Model

Creator Bernie Dohnt planned to sink his fully-functional, 1/72-scale model of Titanic before changing course and selling it to Titanic: The Exhibition.

Bernie Dohnt 3 D Printed Model Titanic On Boat Trailer
Bernie Dohnt’s 3D-printed, 1/72-scale model of Titanic. All photos used by permission of B. Dohnt.

Bernie Dohnt describes himself as “the crazy bloke that built the world’s biggest 3D-printed Titanic.” Dohnt, a 31-year-old marine engineer from Australia, recently completed a radio-controlled, 1/72-scale model of the RMS Titanic, one which is 3.7 meters long and weighs 200 kilos [approximately 441 pounds].

In order to complete the astonishingly ambitious two-year project, Dohnt custom-built a water-cooled computer and assembled several 12" Pegasus printers (from kits purchased from Utah-based MakerFarm), using the 3D printers to print out more than three-thousand white plastic parts. After painting the model, adding concrete as ballast, and putting the ship under power using electric motors, Titanic was ready for trials on the water.

Dohnt doesn’t own a (real) boat, so he had to purchase a boat trailer and then custom-design a “big cradle” to transport the model. “When I drove down the highway, every time I would go to merge to overtake someone there would always be someone next to the trailer taking pictures,” Dohnt says, remembering that little annoyance.

In the water, the model Titanic performed admirably, though a near accident revealed a performance issue that Dohnt believes played a role in the real Titanic’s sinking. (More on that below.) Ultimately, Dohnt decided to float the idea of sinking his model, launching a Kickstarter campaign that aimed to recover his, uh, sunk costs. When the campaign failed to meet its goal of $7,000 (AUD), he changed course and opted to sell the model to Titanic The Exhibition for $2,000 (AUD).

In the following Failure Interview, Dohnt discusses the challenges of building the model, how it fared on the water, and—last but not least—his plan to build an even larger (1/24-scale!) model Titanic, one that will be coal- and steam-powered and capable of transporting passengers.

Tell me about your background.

I joined the Navy when I was 19 and was in the Navy for seven years. Since then I’ve worked for various Navy contracting companies. So what I’ve done for my whole career is to maintain and service ships. Hence the knowledge and love of building stupidly-big model ships.

How did you get started building 3D-printed models?

I wanted to build remote-controlled scale models of ships and I had a look online about how you do it with fiberglass and wood. But I’m not all that great with my hands, so I thought: What if I build a printer that is capable of doing it? The printers I found online were way too small so I ended up building my own printers out of kits, then I started designing the models and printing them out. My first one was an Armidale-class patrol boat, which was 1.6 meters long.

But my end goal was to do a 1/72-scale Titanic model and in September 2015, I started printing it off. It was a very slow process but within nine months I started to see the shape of Titanic slowly come together. I also had to figure out how to ballast it and I calculated 140 kilos worth of ballast, so I used concrete, bringing the total weight to 200 kilos.

Where are you storing the model?

Four months ago I moved from Sydney to Brisbane and I moved Titanic with me. I have a mate who has been kind enough to store it in his garage. But I sold the model last week—at a loss—to Titanic The Exhibition in Sydney, and they are coming to grab it on Friday [August 18]. They will be using it as a display, and they’ve got a model builder who will dress it up and make it look nice and remove the concrete [ballast].

What did you use as the model for your model?

It’s modeled off of line drawings for a standard, DIY model kit. From those line drawings I was able to sketch out every bulkhead partition in the line drawings and it was just a matter of joining the dots to make the hull. The end result is that the model of the hull is insanely accurate.

When you took Titanic out on the water, how did it perform?

I don’t think anyone else has done a model Titanic this big—to scale—with weight, with all of the propellers and the rudder. What I found is that the rudder only works under power. If the rudder is hard over and there’s no power on the propellers but the boat is still moving through the water, it doesn’t turn at all. Based on what I learned from the model, it actually makes sense that the rudder on the real ship only really worked when it was under power.

Essentially what happened is that when the real Titanic saw the iceberg, they put the rudder hard over [while] they were full steam ahead. They started to turn but then standard procedure was to put the propellers to full stop. If the real Titanic reacted in the same way as the highly accurate model I built, that explains why they hit the iceberg. Even though the rudder was hard over, it only works under power, so they started coasting straight ahead.

How did you learn that? Did you have a near-accident yourself?

I did. I initially floated it in some little tidal streams. I was going down one of the tidal streams and came to a corner and thought I had plenty of space to turn. So I put the rudder hard over and started turning around the corner. But I could see I wasn’t going to make it so I decided to try to stop. I pulled power off the propellers while the rudder was still hard over and as soon as I did that it started going straight ahead as if there was no rudder at all. So I jumped into the water with my controller to try and catch it before it hit the other side. I said to my mate, “This is more than likely what happened to the real thing.” After that I took it out to open waters and started testing and [replicated] the issue.

How did you get the idea to sink your model?

My good friend Dizzy filmed the testing and the video got a lot of views on YouTube. So I thought, “What if I sink it?” [And see what I might be able to make from the YouTube video of the sinking.] The problem was that I put a lot of money into the model. I used 70 kilos of plastic, which is about $40 (AUD) per kilo. So I went for the Kickstarter campaign.

If you had gone ahead with the sinking, where would it have taken place?

I don’t know if you know the east coast of Australia but there are a lot of places where I could have done it. I would have done it in 35 meters of water [the accurate depth for the scale of the model], which isn’t hard to find. There are saltwater bays around here in Queensland that are tropical gorgeous and the mate of mine who is storing the ship has a few friends who are divers and they said they would be happy to film it hitting the bottom. It would hit the bottom pretty much the same way the real one did and you’d probably see the same sort of wreckage as well. You’d end up with a very accurate re-enactment of the sinking.

Tell me about the computer and printers you used for this project.

When I went to buy my [first] printer I told Colin Farrer [president of Maker Farm] what I wanted to do and he made some really good recommendations. Maker Farm kits are really, really well-priced because when you get them you basically have to do everything from scratch. You just get motors and the gantry that holds it all together and all of the electronics. You’ve got to put it all together, so there’s a fair bit of work involved. But if you’re able to do that what you end up with is a printer that has the same build volume and capabilities as a $12,000 (AUD) MakerBot. I saved myself $11,000 (AUD) by putting it together myself. I recommend doing that rather than buying a printer because building it from scratch gives you a complete and thorough understanding of how a 3D printer works. If anything breaks or is not quite working, there’s a 99 percent chance that you will know exactly what’s wrong and how to fix it yourself; by doing that you become a 3D printing master.

From there you learn all the different components and get really good at doing nice, quality prints. You’ve got to get your temperatures and speed right and it can be a bit tricky. And printed objects are a little porous; they act as a bit of a sponge for water. The act of painting can seal a 3D-printed model, so it’s pretty important to get your paint thicknesses right if you want it to be waterproof.

As for the computer, I built it specifically to handle the Titanic, because I wanted all of the pieces in one file so I could see the progress of the entire model. Even though it’s really powerful the computer struggled, because there were lots of different high-detail pieces. And while the computer is a little outdated now it’s still pretty strong; I’ve got 32 gigs of RAM and I’m running two GTX 780 graphics cards with an eight core processor.

How many parts did you print?

Well over three-thousand parts. I had to print the hull in multiple sections. I counted about four-hundred parts for the main pieces of the hull and superstructure and funnels. But when I started printing off all of the little bits and pieces that’s when the time and effort started going through the roof. I actually have the design for sale for $174.30 on cgtrader. I’ve sold a couple so far, so you may see another 1/72-scale model floating around eventually. Once you have the design all you need is your own 3D printer and the spools of plastic.

The hobby of assembling plastic models—using the kits you would find in hobby shops—is largely a thing of the past. Does 3D printing have the potential to reinvigorate interest in plastic models?

Possibly. But kids aren’t into building models anymore. When I was a kid you could go into a shop and there was a model section with planes and boats. That’s where my love of models actually started. But I don’t think kids are interested anymore. It requires a lot of patience and, to be honest, requires a bit of intelligence as well. I don’t know if that is being wound back in the newer generations but it certainly seems that way. Nobody has time has to sit and collect their thoughts anymore. How we raise our kids and what we teach them is going to be the important driving factor as to whether hobbies [like assembling plastic models] still exist in the future.

I understand you plan to build an even larger model of Titanic?

Yes, but I’m going to make it out of steel, not plastic. I intend to buy a house with a separate shed in the back where I can mess around with all of my crazy projects. One of the things I want to do is build a 1/24-scale Titanic, which would be about eleven-and-a-half meters long. The reason I want it so deep is I want to put steam engines in it. I love the idea of steam-powered machines and I’ve been doing a lot of research on steam-powered engines. But because of the fire hazard of burning coal inside the ship I plan to make it out of steel. I’m fairly handy with a welding machine and I’ve got all of the skills and knowledge to be able to send off all of the information to the laser-cutter to be able to do it fairly easily.

Will the 1/24-scale model of Titanic carry passengers?

Yes, I plan on being inside it when it sails. There will be space for someone to have a look at what’s ahead and steer, and there will be space in the back for someone to be able to make sure that everything is running smoothly and that the boilers don’t pop.

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