3D Print School: Home Building Assignment

3D Print School Building Assignment: Home Repair

Learning Challenge: Create a replacement part for a working piece of machinery at home using a 3D Printer to create the piece.

Background: The local Cricket Club, who have a close association with our school came to see us because they had a BBQ Knob that need replacement.  Rather than replacing the entire BBQ they requested that we be able to manufacture a replacement part that would be functional and would allow them to continue using the BBQ without having to replace the entire BBQ.

Task: We had the original part and were able to make an accurate copy of it as a result.   The students had to make detailed measurements of the replacement piece. 

Level of Difficulty: Low/Moderate - as we had an original part we did not need to experiment with the measurements or the details.   We simply used the existing measurements (so in this example the students did not carry out a written plan first, we were also on a restricted timetable).

The replacement part, mounted on the BBQ next to the original piece.

Issues: The students were able to complete this repair by the following day.  The only issue came with the width of the internal gap to allow the knob to be connected to the BBQ.  Students had to work out a way to identify the circumference of the internal gap and the depth of it.   The gap also featured a sleeve which was metal as a heat protection feature.  This sat inside knob.  

Timeframe: The students were able to complete the task following a sample print run.   Using Tinkercad they were able to produce a prototype the same day.  It had to be corrected to allow for the internal gap to connect it to the BBQ.  Once one had been printed and the students realised that the gap needed to be adjusted they were successfully able to do so.  The second print worked.

Above: The replacement piece in action

Size: The finished product took approximately half an hour to print and measure 5cm by 5cm and had a depth of 5cm.

Process: The students had an original piece on which to base their designs.   This meant that instead of creating an original piece they were replicating a replacement piece.   We are going to pay close attention to the longterm success of the part - currently there is no apparent damage to the 3D Printed part as a result of the cooking process however overtime we need to continue to monitor this.  We could look at manufacturing the inner sleeve to protect it if required, however at this stage it does not appear to be an issue.  The fact that this worked and the students were able to turn it around so quickly was a strong bonus.  

Problem Solving: Measurement - specifically in this instance the depth required from the internal part and  the circumference of the internal circle.  The concept seemed to be understood clearly by the students but the process involved proved a small stumbling block.   While generic ones could be ordered online it allowed an opportunity to ensure we could design an individual piece that was tailor made for the BBQ.

How Can You Contribute: 
Have you used a 3D Printer to repair something at home? Have you designed or repaired something at home that needs replacing and can you send us the details so we can share and use your examples to encourage others?