Monday 26 November 2018

Botnica Vessel as a Luminous 3D Print

Let go is the only way to find the glow

a little story

TS Shipping LTD. ordered a 3D print of their well-known ice breaking vessel Botnica. 

Compared to beautiful 'old skool' scale models of ships and yachts, I believe that just a 3D print is limited and I wanted to add something special to the 3D print. However I didn't had a good idea so I decided to just continue and keep faith in the outcome.

As the real multi purpose Botnica contains a main crane and main crane support that can be removed for more deck space, it was decided that these parts can also be removed on the 3D print. The same counts for the moonpool top- and bottom covers which are removable parts as well as the aft block cover which is removed for towing operations. Last to mention is that the two Azipods are rotatable, as they are in reality. But still I wanted to add something more, but what?
The 3D print is intended for promotional purposes of this versatile ship. It was decided to print the 97 meter long ship at a scale of 1:250 in nylon. This results in a print of 395 mm long.
With a scale model of 1:250, details with a size of 250 mm will result in 1 mm print size. This is the minimum size for free standing details in this type of nylon print which means that some details will not be printed as they are too small. Or they have to be thickened to be strong enough for printing. 
When it comes to preparing a 3D model for 3D printing, a couple of steps have to be completed in the following order:
  1. Make a decision about the scale of the print. This depends mostly on the maximum printer size and desirable price of the 3D print. The bigger the more expensive as you pay mostly the print powder volume.
  2. Decide which small details have to be printed and make them thicker when necessary
  3. Model the hull, superstructure and details in 3D. Especially the shape of the unique ice breaking hull was quite challenging.
  4. Adding a 1 mm wall thickness is neccessary to minimize the cost of the 3D print as the printing price is mostly determined by the print powder volume. This means that a solid print would become way too expensive. However, to model a wall thickness is quite laborious as the total model should be one single watertight closed solid polysurface from a 3D modeling perspective.
  5. Several frames have to be added to strengthen large span surfaces like the deck and sides of the hull.
  6. Creating openings for removing the non printed nylon powder.
  7. Connecting the separate parts (main crane, crane support, Azipods etc.) to the main model with two small connection rods. These parts can be cut loose with a sharp knife at a later time. This minimizes the printing cost as it is considered 'one print' by the 3D print supplier.
  8. Meshing the model and export as an STL file.
At this point, also due to delay in the delivery deadline, I decided to give up on 'something special' for the 3D print. Therefore, the print was ordered at Shapeways and turned out problematic. During shipping, the front part of the heli-deck was damaged. Also several tiny details of trusses were broken during the cleaning of the 3D print. As the printer builds the 3D print up in layers of nylon powder, after the printing process, excess printing powder has to be removed with air pressure. This cleaning and other handling can damage small parts. The 3D printing service company Shapeways was very supportive and immediately offered a free reprint of this valuable print.
As I was examining the 3D print, I found out that a lot of excess nylon powder was still in the 3D print as Shapeways discontinued full cleaning after disapproval of the print.
Then I decided to use an LED light to find out how much and where the excess powder was located. It struck me how nice the light was illuminating the 3D print. It was then that I had the idea to add LED lights to the base to illuminate the 3D print. So this is the story to get to a unique and special result!

It was great pleasure to receive the second 3D print and finish it for the patient client TS Shipping LTD. They are very happy with it and want more!