3D Printed Model Catamaran Boat - Part One

Above: Original design from Tinkercad.

Challenge: For student to produce a working model of a boat (in this case a catamaran).
Background: Tinkercad as a version of software are continually evolving and looking at producing new ideas, which are released as part of the design software.  A student from my class who is ten years old was able to locate the new design features and located the 'boat hull' design template.  The student concerned has a talent for design and engineering and is forever tinkering and creating projects, which is a great strength of his.  In this example he was fascinated with the prospect of creating a boat.   It was reasoned that by 3D Printing the hull that the boat would be able to float, or should be designed to do so, including problem solving to ensure that it was a workable model.    This is the students first draft attempt at completing a boat.  He has already looked on Youtube to develop possibilities for a working motor that would work in conjunction with the boat.  The first task was to complete the hull, test it to ensure that it would float, and look at altering the dimensions, print settings etc to ensure that this was possible.

Completed print with cosmetic sail

Level of Difficulty: Medium, the hull design needed to be workable (see below) which would allow more advanced features to be added.  While the hull template came from Tinkercad the decision was made to create a catamaran for the balance that it would provide for the base.   At this stage we were still investigating the best way for the boat to work.   The sail shown on the right hand side was for decorative purposes as the decision has been made to look at including a motor to power the boat.
Timeframe: The total print time for the base of the catamaran was ten hours.  There was minimum rafting with the print, the masts were having a cosmetic effect, so they could have been resized.   The base of the catamaran was designed to provide stability to the print, first and foremost.   The nozzle was 8mm and the print setting was 'regular'.
Size: The length of each hull is 18cm.   The width is 2cm and the height was 2cm.   The middle of the catamaran was essentially a 12cm by 8cm rectangle, with a depth/width of 5mm.  The smaller mast was 9cm high and the second smaller mast was 6cm.   Given the purpose of the print is to have a motor fitted at the back to power the boat, the dimensions are about the minimum that is required.
What we would do differently: This chance find has opened up a whole level of development of 3D

Above: Water testing the prototype

Printing for our students (which has ironically come in the last regular week of school).   The boat design required specific requirements with the intention of a motor being used to power the boat.   Given the success of the initial print (we were not even sure if the PLA used for the 3D Printer would actually float, or we would need to hollow out the inside of the hull).  Going forward there will need to be a location for the motor to be housed on the design.   
Next challenge for the students: The sails of the prototype are purely cosmetic, the students could consider using a fabric that might have a practical use.   The dimensions of the catamaran seem correct at the moment, however this will be dependant on the size of the motor, and how this will relate to the design.   We are currently sourcing a motor at the moment which will require the design to be revisited.    We will be water testing the design over time.