Using 3D Printer to Repair

 

A range of purchases have been made from our students during the course of the year.   Some are purchased locally at markets and events where there are typically someone selling 3D Prints.

We also have a number of students who have come to us with examples that they have purchased online.   In both cases we are really careful to ensure that we are respectful about the purchase but we typically see if we can locate the source of the original file and in particular a cost or price point of comparison.

We have also started to realise that we need to consider from time to time repairing prints that might end up worse for wear as not every print is a suitable toy or at times can be damaged by an accident or play.

Such was the case with this character from Roblox Cappuccino Assassin.   This figure had been purchased locally but as can be seen from the photo the legs and the arms do not have the strongest points of connection.  

While we couldn't repair the original foot (which had snapped at the connection point) we were able to have students source from the Bambu Labs online design forum the original print (in fact there were multiple versions of this character).

Included on this forum were the step by step printable parts for the character.   While we didn't have a point of origin with the shoes and were unsure of the printer that was used (other than the fact it was most likely a multi coloured Bambu) we were able to use our Bambu H2D machine with its colour matching to produce a copy of the shoes which in this case were two different colours, which just happened to be the filament that was available in the machine.  The student is now going to remove the other leg and then replace both of them with the new variation that we have printed.   The blue new shoes took twenty minutes to complete on the regular default settings.

3D Printed Animal Hay Feeder Model

Above: Original design with props.

Challenge: To create a farm accessory to work as a hay feeder.  The print needed to work in conjunction with a number of other items such as hay bales and model to scales cows.
Background: Following the success of the students who designed the four and eight calf feeder designs for the farm toy business the students decided that they wanted to target the next item on the list which was a hay feeder.  This involved creating a base with bars and a cage.   The students who designed this originally decided to create it as a single piece and as a result there was significant amount of rafting.  As a consequence the removal of the rafting was relatively difficult - there was a bar that was popped out when it was removed. The students were then faced with a challenge - how to produce the cage without having to produce so much rafting. 

Redesigned version with separate base and poles

 The solution which they came up with was producing the cage in stages, first as the base and the top, with the second stage being the base of the platform having holes in it which the poles could then be inserted into.   This was a slightly complicated process as it involved including the depth of the poles into the base etc.    However the students were able to half the printing time for the project and remove the need for rafting.   The students are again creating this prototype as a potential commercial project for a company that produces farm themed toys and sells commercially.

Level of Difficulty: High - this is producing a product that is potentially going to be made commercially and requires the base, base and top level to work in unison.   It has required considerable reworking to get the measurements and design to a point that it would be considered to be completed.   This has stretched some of the top design students in the classroom to their limits to complete it with the minimum amount of printing required.
Time frame:   The original design that was a one single piece design had a significant piece of rafting and had a ten hour print time (see photo left) the revised version with the students creating individual bars and a separate base and lid was five hours total for all of the parts of the project.   This second version has virtually no rafting and therefore would be the direction to move in the future.  The normal default settings apply as always, which is an 8mm nozzle and 20% infill.

Size: The design measure 90mm across and was 80mm deep.  The design was 60mm high and the top frame had a 10mm box design as its framing.  Relative to the design of the hay and other animals this fits perfectly with the expectations for the design.
What we would do differently: The students underwent an extensive revision process to get this design correct including considerable reworking, measuring and development.   Little additional design is required with the exception of a stand for the cage, as it has one in real life.   The students themselves were the ones that drove the improvement based around the printing differences between version top left (ten hours of printing and considerable additional rafting to maintain its shape and form).    The second reworking of the design and print involved the bar rods being printed separately and featured and insert in the base, you can see this clearly in the photograph of the print with the bar removed shown in the top right hand photo.

Left: The two designs side by side.   The ten hour version shown on the left, the five hour version, prior to the super gluing on the right. 

The two designs are nearly identical but the students by breaking the process down and printing as component pieces instead of a single block design have halved the time that is needed to produce the project and reduced the amount of PLA (plastic) used in its production by nearly half.

3D Printed Calf Feeder Model 2.0

Challenge: To produce an authentic to scale model of a calf feeder that was capable of feeding up to eight cavles at one time.
Background: This is the second version of this project.  In the inital version on this blog the student had produced a four calf feeder which was for potential use with a commercial business.   This model had to be produced as detailed in previous post.   This has taken number models and prototypes until the 'four feeder' was successfully produced.  The next step was to change the colour varation, which is a simple matter of changing the print colour and then increasing the size of the print.    This has involved significant testing and reworking to get the dimensions to scale - as this is is a potential collaboration between our school/students and a local business creating something to use with existing products not easily available on the market.
Level of Difficulty: High - this is a precision piece that needs to work to a specific size, be mounting successfully on a model fence and meet the needs of the cow models to interact with.  There is no margin for error and this requires precision, which has been a positive if challenging experience for the students.
Timeframe: Two hours - this has been produced with a 8mm nozzle which is our default size.  Consideration has been given to reducing the size of the nozzle to increase the quality of the print.
Size: This print is 80mm long and 25mm wide.   Crucial to the success of the print has been the hinges at the back which have been designed by the students.   These have allowed the feeder to be clipped into place on the fence.    Students have been experimenting with producing the best fit design to do this. 
What we would do differently: Our students are having a meeting examing the commercial aspects and considerations of mass production, they have identified a potential fault with the design and want to look at the considerations of its use (as a toy) relative to the strength of the print (specifically on the hinge that they have deisgned to hang it to the model fence.    As noted there is a potential issue with the size of the nozzle as well - it may be a print that we produce a higher quality print with my reducing the nozzle size.