Analisis and conclusions in 3D Printing

ANALYSIS AND CONCLUSIONS OF MY EXPERIENCE IN 3D CONSTRUCTION

Given the interest that my developments have aroused lately, it seems to me the right time to tell you how I came up with the idea of ​​starting this project.

Given my training oriented towards naval architecture and my passion for competitive sailing, I have decided to write a kind of guide or explanation of my concept or philosophy on the construction of boats with 3D printing technology based on my experiences accumulated since 2019

It must be said that this is not a definitive explanation since 3D printing does not stop evolving and that is fantastic!

The main problem I see is the lack of knowledge about this new technology in most people who do not understand the advantages and disadvantages of this construction method.

I want to start by saying that a 3D printed boat will never have a surface finish like a fiberglass boat. They may have an acceptable finish that will depend on the time spent preparing the surface once the hull has been assembled, but that will cost time and money.

What I want to say here is that printing a 3D boat is not expensive, you just need a printer or a printing service, a file, a filament spool and the desire to do it. What can be expensive is preparing the surface so that it shines, although as you will see later it may not be entirely necessary.

I have experimented with various techniques to obtain correct surfaces.

The first time I printed a boat I did it with a very thin hull that I then stratified with resin and fibers, but it was a colossal, dirty and not economically viable job.

Afterwards I tried just sanding and polishing, it works very well, but it is a very difficult and slow job.

I then painted some boats, but this is also a difficult, dirty job, and the slightest touch makes the paint peel off making it difficult to keep a boat in perfect condition by doing paint touch-ups.

One of the last techniques I have tried is covering it with a plastic film like on cars. This is interesting for several reasons, first it is not a dirty job, second the plastic film gives the boat superior resistance to impacts, safety against a possible crack, and finally we have a great variety of colours that we can combine in different parts of the hull. This is my last favourite technique.

I also have to say that many of the boats I have built I have sailed without doing anything, that is, raw from the printer and just sanding a little at the joints of the sections. Surprisingly, it is with these boats that I achieve the best results in regattas!! (maybe the golf ball theory has its effect on our scale??). Other advantages of leaving the boat in its raw state are a substantial reduction in time and money, being able to quickly have a boat in the water without needing a suitable space for sanding and painting, something very interesting for people who live in apartments.

Regarding this subject, my philosophy is to be able to change hulls in an economical and periodic way, preserving the appendages, rigging and electronics, in which only a first investment would be made, being able to reuse them from one hull to another, substantially reducing the cost of boat changes as they evolve, allowing us to always be at the forefront without spending large sums.

To sum up, for those looking for boats in perfect condition of finish, for now this is not your path, you will have to wait for the evolution of this technology and materials to reach these goals.

From here I will talk a little about my designs and why they are so different from the norm.

I have to admit that when I started to draw my first IOM I did not want to copy or adapt existing designs, as I had my own ideas. Although there were some boats that I liked, such as Vickers in general. Bravo Mr. Vickers for being the first to find such beautiful and performing shapes, but for me there is no interest in following your steps by drawing a similar boat, rather than that I would buy a boat from you directly.

Instead I began to reflect on shapes very different from those found on the market and to make prototypes to test. In general my main interest is the performance of the boat and not the aesthetics, that explains why my designs are not pretty. For me, the important thing is that they are not copies, and also, someone told me one day in a regatta that a winning boat automatically becomes a good-looking boat. So I concentrated on trying to make winning boats or at least performant ones like the best fiberglass boats!!!

I try to make fast boats through the shapes of the hull, the appendages, and through the sails and their settings, which I design and manufacture as well. This is where I have obtained my improvements in performance from one boat to another.

I have also realized that the final speeds of the boats are practically the same among all of them and what makes one design different from another is the behavior of this one in the face of variations in wind intensity, waves and maneuverability.

There are boats that have a hard time getting started and others that get started very quickly, that is, they break the inertia more easily than others in the face of eventual changes in direction of the boat or instant changes in wind intensity, to explain it somehow.

This also affects the sensitivity achieved in the sensations received through the transmitter of the boat's behaviour, and this makes it easier to find a correct balance in the boat, allowing one to concentrate more on the tactics of the race, providing an additional advantage.

The main feature at the construction level in which I have managed to distinguish myself in reference to other designers of 3D printed IOMs, is the fact of having integrated all the internal reinforcements, accastillage and rigging anchor points in the three sections of the hull so that they are printed in spiral mode without the need to use the normal printing mode and without the need to place printing supports. This minimises the number of parts to be printed, increases resistance, watertightness making it very easy to assemble the boat with practically 3 pieces.

It is very difficult to explain this in words, and I do not want to criticise other designers at all, I respect them enormously and I know that they also do an excellent job.

To give an example, to print other boats in 3D today, you need to print between 20 and 30 pieces that then have to be assembled, aligned, drilled, anchored, etc., etc.

At the beginning with the GLD-05 I also went in this direction and I told myself that it couldn't be possible to build a reliable plastic boat in this way. With 30 pieces to print and assemble it's not worth building a plastic boat, many pieces could come loose, the holes for the fixing screws of the rigging would weaken the hull as well as potentially cause water ingress over time and it would be very difficult to align all the pieces correctly to obtain a symmetrical boat, etc., etc.

So I decided to focus on developing a hull with all the reinforcements and fittings integrated into 3 hull sections, and where it was not necessary to make holes in the hull to place screws, instead I thought of a coupling system that is directly integrated into the boat design ensuring improved strength and watertightness.

This allowed me to facilitate assembly and achieve a symmetry of the main axes, namely centerboard box, rudder, mast without having to align anything, by joining the 3 sections everything is already aligned.

The fact that I had chosen the 400mm high Artillery Sidewinder x1 as my first printer was a determining choice in what I do today. Without knowing it at that time this helped me to develop my boats with this philosophy of the minimum number of parts to assemble to obtain a reliable hull.

Unfortunately, the disadvantage of this choice is that not everyone will be able to print my designs without having a printer of at least 350mm in height, and this is because the way in which all the internal reinforcements are drawn so that they can be printed without supports and in spiral mode to improve the strength and watertightness of the hull does not allow me to cut the boat into smaller sections.

I have made this choice aware that in this way I will limit the number of people who will be interested in building my boats, but in this way I make sure that those who do can make a reliable, easy and very fast boat to build. Minimizing the potential negative opinions that people could have when assembling multiple pieces and their potential problems.

Finally, I will talk a little about the materials authorized by the IOM class rules that I have tested.

Normal PLA is made from Polylactic Acid, which is extracted from plants. It is the easiest material to print, there is a huge variety of visual effects that can be obtained depending on the brand and type of PLA. But these filaments are not suitable for the use we will make of a boat for two main reasons, their low resistance to impacts and their low resistance to high temperatures.

PLA + from the Esun brand, this was my number 1 choice for several years.

It has very good adhesion between layers making it excellent in impact resistance, but it has the same defect as normal PLA, which does not support more than 55 degrees, from which the structure softens, causing deformations if we are not careful.

PETG, I have not had good results making boats with this material, but I know that there are people who have. For me the problems were due to a fragility to impacts and that in general it was softer than with PLA +.

ASA and ABS, I also had no good experiences with them, very fragile to impacts and very difficult to print. I was only able to make correct accastillage pieces with these materials, but being so difficult to print it is not so interesting.

Nylon, a choice that I am currently testing, for now I have only tried PA6GF which is nylon with fiberglass, it has excellent resistance to impacts and high temperatures, but I made the mistake of not reading its characteristics well. It turns out that it does not withstand humidity and loses its characteristics in contact with it. Soon I will do a test with PA12 which is more adapted to humid environments, if it maintains the resistance of PA6 without the problems of this one it will become my favorite filament!

PLA HT, Currently my number 1 choice, easy to print, resistant to impacts, resists up to 130ºC without deforming. I have tested it throughout the year 2024 with a boat decorated with a carbon-like black film covering to help it raise the temperature when exposed to the sun. The boat passed all the tests without suffering any damage or deformation, even leaving the boat inside the car in full sun has resisted!!!

To conclude, I hope that my analysis helps those who are inclined to develop their boats with 3D technology, either by designing their own boats or buying existing files and also make clear the differences that exist in the evolution of designs between 3D boats and boats laminated in traditional molds for obvious reasons.