When it comes to ‘making,’ there are those individuals who tend to think inside of the box, and then there are people like Filip Sjöö, who would rather think way outside of the box. This was the case for his 3D printed dishwasher, which we reported on back in February, and it’s also the case with his clothing design company, Headface.
However, thinking outside of the box might just be an understatement when you consider Sjöö’s recent submission into the MakerBot/Thingiverse ‘Make It Float’ Challenge. Rather than following the path set by other designers and creating a boat which can float and move about the water, Sjöö decided to create something a bit different, in a project that he simply refers to as ‘Make It Sink.’
“I had a lot of ideas on what I wanted to make for the challenge,” Sjöö tells 3DPrint.com. “I wanted to make something that moved, and to make something that moves you need energy. I didn’t want to use electric engines or stuff like that, because that would have made it harder for other people to replicate. I wanted it to move when you put it in to the water, without having to do anything else, so I came up with the idea of using the kinetic energy of the water around the boat, by simply making a hole so that the water could flow into the boat, and then collect the kinetic energy with a water wheel.”
The use of a water wheel is no new concept for Sjöö. In fact, he used this mechanism in the dishwasher that we reported on in the beginning of the year. Using the water wheel to collect energy, Sjöö needed to decide on how his boat would move. He first considered adding a propeller to the back, but then realized that it probably wouldn’t have had enough power to move the boat very far. He then came up with an idea for a pipe that squirts water into the air as the boat sinks, but in the end decided on a completely off the wall idea.
“In the end I decided to make a boat with a man that waves his arms at the same time as the boat sinks,” Sjöö tells us.
In designing his ‘Make it Sink’ boat, he decided that the entire creation would be 3D printed using PLA, and would require no other materials whatsoever. Instead of using glue to hold the parts together, he would create parts which could snap together like Lego bricks.
He first began by designing the boat’s hull using SOLIDWORKS, before moving on to creating the boat’s actual mechanics. This took a lot of calculations in order to figure out exactly how much the boat needed to weigh, and how much water it would require for the mechanism to function properly.
“In order to make the water flow into the boat, it needed to weigh about 450 grams,” Sjöö tells us. “We were encouraged to use coins as weights in this competition, so that was a great way to get to the 450 grams needed. The volume of 450 grams of coins are under 78000 mm^3, which would easily fit in in the boat since the displaced volume was about 450000 mm^3, and the total volume of the boat was even larger. To make the water wheel spin as long as possible, I made a ‘lid’ so that the money could lay on top of the water that was flowing in, so that as much water as possible could fit, without the water level rising so much that it stopped the water wheel. “
He then had to calculate how much water would fit into the boat before the water wheel would stop functioning, and then create the gears which would ensure the man’s arms would wave at a decent speed. He ended up setting a gear ratio of 1:4 so that the man’s arms would go up every four seconds or so.
Designing the water wheel was the most challenging aspect of this project, as Sjöö tells us he went through six iterations before getting a wheel that would actually turn. Once he finally got this working, it was off to creating the attachments and other gears, before getting to the fun part: creating the head and arms for man in the boat.
The man in the boat isn’t just anyone. In fact, it is actually Sjöö himself, combined with his father and a friend. Using a cheap Xbox Kinect that he found on eBay, he scanned his head, his father’s hand, and his friend’s arm, before 3D printing them and then combining them to make the man in his boat. As you can see in the video and photos provided, Sjöö’s ‘Make it Sink’ boat is quite unique.
“When there is enough weight in the boat, the water flows in through the hole in the bottom, and up through a pipe and down through a chute where it drives a water wheel,” he tells us. “The water wheel drives two gears which reduces the speed to ¼. Then a shaft and a crankshaft transfer the energy to the arms, and makes them go up and down at the same time as it slowly sinks to the bottom. The purpose [of this creation] was partly to win the competition, but also to amaze and inspire people with a thing they absolutely never saw before.”
Sjöö’s design ended up being one of the winners of the competition, rightfully so. He has made the design available on Thingiverse for others to download. It consists of 21 3D printable parts, with one part that needs to be printed twice. It takes approximately 12 hours to print the entire boat, with the hull taking about 80% of this time. Let us know what you think about this creation in the ‘Make it Sink’ forum thread on 3DPB.com. Check out the video of the boat in action below.