Exemplar Boat: Problem Solving the Catamaran

 

As we have mentioned and detailed in a previous post on this blog we have previously developed and planned a Catamaran, as part of a class challenge for the students to build a boat.

The student concerned put a considerable amount of work into the project - but initial trial prints raised some issues from a range of areas.   The student themselves had the design undergo some significant testing to identify the errors in printing, and also look at what solutions that they might be able to use to resolve issues.

In the first version, two small join holes, created when two linked parts of the boat met, caused a minute hole which allowed water to enter ultimately causing the boat to list having taken on water.

The bow of the boat was designed more as a space that looked appealing, instead of being more water tight, so once water came into contact with the front of the boat it tended to cause it to start to take water onboard.   

The mast was designed to look appealing and not be functional, so the students reinforced it making it stronger.   The steering wheel is only visible in early designs as when the rafting was removed the steering wheel needed more robust attachment.

The base of the boat was reinforced with additional shapes and additional blocks to ensure that it was waterproof.   Previous testing on the early versions of the print identified that it was unable to sink.

The dimensions of the print have not changed, as the base is the same that is 140mm long, 120mm across and the cabin being 60mm high.   The print time was eight and a half hours, while this is significant, this is a particular detail process with a specific intention to complete a working boat, it features a high degree of difficulty. 

The water proofing that was attempted was initially using blu-tack.  This was discovered to be acceptable but the student wanted to upgrade to use a hot glue gun as he felt that would be more succesful.

3D Printed Boats: Catamaran

Challenge: For a student to create an original boat.

Background: As part of the challenges that we are giving the class of students this year we recently gave them a 'boat' making challenge.    Experience has taught us in the past that the 3D Printer is able to produce an object that will float, due to the typical infill that is present in most printing.   This has meant that students have been able to produce themed prints (such as bath toys which we used as part of our school market day, which was last held in 2023).

We also had our senior students attempt to create Catamarans in the past (due to their balance).   You can see examples of this that were originally produced in 2017 and later variations and expanded updates from 2019.

This is the first attempt at a project like this with our current classroom which consists of junior school students who are seven and eight years old.

This project was open ended in that it was presented to students and they were encouraged to come up with an original design.   The students were provided a very basic example to help guide them, but were also encouraged to push themselves to look for real life examples that they could draw inspiration from and have details that they could mimic with their designs.

The teacher also demonstrated to students that Tinkercad, which was used for the designs,  includes as part of its object interface a hull option.  In this design shown in this post the student was able to use the hull from here as the main basis for the twin hulls.  He then made a third copy of the hull which he flipped/inverted, shorted and hollowed out which is the shape that he used to make the cabin.  Having located various Catamaran photographs he then added additional details such as the sides, the sails and then used various shapes to build a steering wheel.

The student from start to finish was able to complete the design within a thirty minute period of time.

Level of Difficulty: Hard - this students is a Y4 student however he was able to use Tinkercad to manipulate and make a Catamaran in a short period of time, this is by far the most complex and detailed project from the class as a whole, for this task, and also that this student has attempted.

Timeframe: Eight Hours.   There was considerable rafting that was present with this print, as the base of the boat, between the two hulls and the floor, needed to be printed with support which had to be removed.

Size: This is a large print, 140mm long, 120mm across and the base (the cabin area was 60mm high).

What we would do differently/next steps for the students: There were some issues with the print that were not apparent when this design was completed.  There was a very small hole that was at the base of the boat where the hull joined the floor.  Although this was only 1mm or less it allowed a small amount of water in, which overtime caused the boat to list.  This was an awesome teaching experience as the student tried to work out ways to plug the leak.  He applied blu tack the first time, without success and then started to look at water proofing - he was also concerned that part of his print was not water-proof, and has begun the process of taking the boat, placing it in a container and then checking on it to see if it has taken on any water.   He has already discovered that the boat itself isn't going to sink, as the cabin ensure it remains afloat.   Again the learning experience from this is rewarding and the student will be looking at several aspects of this.   The steering wheel which is clearly visible in the AR/VR version of the print (photograph shown above) did not survive being robust enough.   The student is also looking at what he can add to the overall design to improve its presentation.

3D Printed Catamaran - Exemplar Project Update

The Revised version of the print Catamaran (2019)

Challenge: To produce a boat that could float.
Background:  This has been one of the longest ongoing projects that we have been actively working on or tracking on this site.  In its original format a student two years ago started to investigate the properties and details of a 3D Printed Boat, which eventually moved towards becoming a 3D Printed Catamaran.  Details of those projects can be located here.  The student concerned recently revisited this project (which began when they were nine years old at our School).   This time armed with more knowledge and concepts about the model he looked to complete the project and further modified his design.    One of the aspects of the design that is not shown in the photograph was to aid the buyoancey of the boat is that air pockets were introduced into the twin hulls to further allow it float, the initial designs had simply had a regular infill of 20%.   The teacher who was also invovled in the producing of the boat was interested in experiementing in pasting on a 3D Printed Coating - to allow for further decoration (hence the shiny design feature that is visible in the photograph). 

Above: Design shown in profile

Level of Difficulty: High - this is an exemplar thats design and creation has taken considerable time and reworking, numerous test versions to get to this point.  The scale and design, the details and project have taken hours and hours to get to this point.   Not for the faint hearted.
Timeframe: Fourteen hours to complete this print with the regualation default settings featured on this blog.  There was minimal waste printing so the ability to reduce the time was a small window of opportunity only. 
Size: The hulls of the design were 150mm in length, 20mm wide and 50mm from the top to the bottom of them.   Eyelits were introducted for the possibility of a sail used in combination with the boat, and the size reflects that potential. 
What we would do differently: From this point of view the student appears to be satisified and looking to move forward onto other projects - the is the question of whether or not a motor was placed on the hull or base of the boat, but the emphasis was on a Catamaran.

3D Printing Project Updates

 Left; This project was originally featured a considerable time ago and is based around using the 3D Printing PLA to produce a Catamaran.  This was first conceived in December 2017.  In this revised version the insides of the hulls have been deliberately left without infill to create air pockets to assist the boat to float. 

This is a considerable print looking at sixteen hours to print in its current form.  Details of the original print/project can be found here.  

Left: The most recent print on this site, the robot that is incorporating a pencil sharpener has had further development which has been driven and come from the student (ten years old) who designed the print.  While the teacher considered that the print had already been completed this student was adamant that it was not completed and was determined to include a second coloured print to contrast with the base colour and produce some basic features that would add depth to the print.   While these were only small additions to the print they produced a striking addition to the print.

Details of the original project/print can be found here. 

3D Printed Gift Display

Challenge: To create a personalised gift commenerating a special event (in this case a birthday).
Background: Student had been somewhat inspired by a previous print detailed on this site, from February. She had seen this design and its influence on this design is clear to see.   Initially a plan had been to spray paint the design, however the student (Y6 - ten years old) was extremely pleased with the finish created by the white PLA and decided for it to remain as it was.
Level of Difficulty:  Low - its a basic template design, with the addition of the lettering and some of the generic designs accessible from the main screens.   The font selection was the default. 

Above: Design shown in profile

Timeframe: Twelve hours - there were significant design changes would  have reduced this time, relating to the depth of the print.  At 20mm deep it could have been halved which would have reduced the time of the print significantly.
Size: The design measured 15cm across, which was identical in size to the original print. 
What we would do differently: The student was thrilled with the design and the finished product.  The student herself did not want to change any aspect of the design, despite the points noted above which were discussed with her.
Next Step for the Student: The project and print are essentially completed and done and the student would move onto other challenges and projects.

3D Printed Catamaran Boat V3.0

Challenge: For student to create a working model of a boat that floats and is able to have a small motorised unit attached to it. 
Background: The students from our classroom (and school) from New Zealand have returned to school and are completing projects that were designed and put together at the end of the 2018 School year.  Previous versions of this print run had been designed to include masts, in the first version, detailed on this blog here.  The second version involved the removal of the masts of the ship, to spend time focussing on the balance and hull.  In the first version there was a middle platform which provided stability, but the student concerned wanted to create a realistic catamaran as possible, hence experimenting wtih removing it. 

Level of Difficulty: High - this is an incresing complex print with a number of factors that are increasing difficult to balance.  The student himself would be one of the most technically gofted design students who consistently shows excellent problem solving and adapting of his designs.
Timeframe: This print took twelve hours and the design required significant rafting.  This should not be considered to be additional to the shape and would need to be required to remain with versions of the print.
Size: The hulls shown in the inserted photographs were 15cm long, had a width of 2cm at their largest and were 5cm from bottom to top.   The strengthening cross beams were 10cm acoss.   The masts shown were 9cm high. 
What would we do differently: This version of the boat was not as successful in terms of how robust, and the balance that it has.  In the previous versions of the print the masts were thinner and the base of the design was balanced by the base.   When tested in water, in the school swimming pool, the boat tended to flip easily and was clearly top heavy.   The student has recognised this fault of the design, and already completed testing with this print and as a result has redesigned it, thinking about balance, and started to look at the design of the Americas Cup Boat.

3D Printed Model Catamaran V2.0

Above: Catamaran V2.0

Challenge: To produce a working model of a boat that would be powered by and engine or sail.
Background: Following extensive testing of the initial prototype discussed in the previous two posts the student concerned decided to redesign the base of the catamaran, removing the centre piece and attemping to show a more traditional catamaran style.  The student concerned in this series of prints related to this project is a ten year old, who has shown considerable skill with the design and creation of a number of school projects during the course of the year.  The initial design featured in the previous print came about as he discovered a 'hull' basic shape had been added to the Tinkercad basic shapes interface.   This led to a discussion about creating a 3D Printed model boat.   Extensive testing has shown the PLA to be ideal in water situations, the buoyancy proving to be excellent in allowing a boat shape to sit perfectly in the water, this updated version even more so than the original.  The original design featured masts - this revised version did not, as the masts in the first version were purely cosmetic.   One key element that will need to be addressed is the mounting of the motor to power the book.  A custom made piece will need to be printed and designed (altering the above shape) to house the motor and prevent it from getting wet.

Above: Hull showing underside

Level of Difficulty - Medium,  essentially this task has been about completing a prototype basic structure and to test the viability of printing with PLA in 3D, this has been a resounding success, however the level of difficulty is to increase significantly as additional features are to be added to the shape to include masts and a housing unit for the motor,   to successfully add these features will be a challenge.
Time frame: Redesigning the hull of the boat, and making the changes that were made from the initial print has also significantly altered the time to print the model.  The first version took ten hours, the V2.0 time (again with 8mm nozzle, standard Ultimaker settings) was seven hours, and potentially could have been reduced further relative to the depth of the hulls.
Size: Each hull was 15cm long and 5cm deep, they had a thickness of 2cm.   The bar to join the two hulls together are 8cm across, 5mm thick and started three cm from the bow and stern of each hull.
What would we do differently: the students are enthusiastic and really seem to be onto something here.   The basic design has again exceeded the brief.  The boat itself as noted previously seems extremely stable and is not easily able to be flipped - we have continued testing it by dropping it from heights up to two metres and the boat continues to float, hence we would do little differently at this point.
Next steps for students: The designs greatest challenge will be incorporating a power source successfully to act as a way to propel the boat while in water.   The students have the possibility of using a sail in some capacity although this will complicate issues relating to the material that the sail is made from. 

3D Printed Catamaran Boat - Part Two

Following the success of the previous print, of the model of the Catamaran Boat Model the student (ten years old) who crreated the 3D Printed model boat decided to 'road test it' by floating it in the school swimming pool, to test its ability to float.  As mentioned in the previous print detials the sail was for comestic purposes only, as it was made using paper.

The boat was tested in the water for one hour, and did not sink, or show evidence of sinking at

all.  Water covered the top of the design, however it 'washed' off allowed the boat to remain bouyant.  We further tested the boat by throwing or dropping it into the water from 1m to 2m height and then skimming it as far as we could 'flip it'.   During this level of testing the boat would not sink or tip, it simply comtinued to float.  If the boat was delibrately flipped and turned upside down it would remain in this state. 
The damage shown to the mast left occurred when a student flicked the design, and it hit directly the edge of the pool.  This caused the mast to break off (as shown).  However while the mast itself would sink when held below the water,  the base of the boat would not even when it was held underwater on the base of the pool.

Given all the testing that was carried out in the last two days the design is practical in terms of its water durability and water tightness, a regular print will not sink as the PLA continually refloats.  This design as shown while it is basic represents the first basic print and design in the series.  The inention is for the students to design, manufacture and mount a motor onto the boat to allowed it to be semi-powered which will provide the next challenge for students.

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.