3D Printed: Stoat Sound Lure Prototype V1.0

Above: The three component set up.

Challenge: For students to work on producing an electronic sound lure that could be used in conjunction with traditional trap.

Background: This has been a major project for our students during the course of the last ten weeks of school.   The students have been entering a regional/national competition that is based around innovation and creativity.  The competition was for Y5-8 students and our students were able to enter the Wanganui/Taranaki finals as a starting point with the opportunity to make the national finals.   The entry of the students in this competition came as a result of work of our students over a significant project in the last year.  The challenge for the students was how we could use technology to assist the removal of pests in New Zealand. 

Above: The base set up.

Stoats, Weasels and Ferrets were introduced into New Zealand in the 1800s to assist in the control of rabbits.    These animals instead switched on to preying on native New Zealand birds, who have no defence against these animals. 

Traditionally they have been trapped by using traditional manual traps. 

The challenge for our students was to use technology to assist in the trapping of these animals.    Our students spent considerable time completing background research and looking into the process.   There are currently no available versions of this kind of lure, although they are currently in development.  We spent considerable time looking at opportunities to develop the technology associated with this process (further considerable detailed information on this process is available on request contact the teacher concerned here at this blog if you wish).

There are three separate 3D Printed parts of the set up for this project.   The first is the base, as is shown by the purple print.   This is a set up involving a breadboard, which features an MP3 player and a picaxe to control it, including in the circuit a light sensor and jumper leads to power the set up.   
This part of the unit has been featured on this blog in previous posts and can be located here.   The idea is the 3D Printer can custom make the sound lure and the base design can be altered as appropriate.   The chip can play sounds which are stored on a micro-SD card (up to ten thousand sounds of varying length).  The light sensor is able to be coded to allow the speaker to operate at pre-determined time, as a value can be entered to measure the level of light and then switch on as appropriate.   There is an opportunity to target specific times when there is more lightly to be pest activity, have specific lure sounds (for instance there is evidence to strongly suggest that stoats are more likely to target chicks instead of ears as they hear better than they smell).

Above: Speaker variation with removable lid.

The second component of the set up is the speaker box.   This is designed to house a speaker that will produce the sound for the project.   The design is reflect the need for water proofing and also to allow a sound to be emitted.   This speaker design has gone through significant development as the students experiment with sound variations and quality of sounds.   The initial designs for the customized speaker box was featured on the blog here.   The students have been looking for the balance between the box and the ability to protect the electronic parts (as the speaker and the set up is being deployed into a outdoor bush setting).   The lid that was featured with this design had an insert which allowed the speaker to sit in the box.  The height of the box was designed to allow the sound to be omitted.    Evidence suggests that while a traditional meat baited trap has an effective range of five metres it would appear that the sound lure variation is effective for up to a hundred metres.   

The final component piece of the set up was the power unit for the device.  A prototype that was supplied to our students was a battery powered noise created set up.   One of the variation that the students were looking at was to provide a solar powered option to run the set up.   The students after considerable investigation opted for a solar panel combined with a lipo battery.   The size of the featured solar panel was 70mm by 110mm.  It had a height of 10mm.  This allowed it to be water proofed.    There are variations of the solar panel in sizes, so the 3D Printer is ideal to adapt to the different sizes as the unit is produced.      There is not expected to be the same level of variation with the micro-chip box, although as we are experimenting with different sized speakers so again the flexibility of the 3D Printer is ideal to create the opportunity to customize.

Next steps for the students: The students won the regional competition and have qualified for the National New Zealand finals in December.   The students need to produce a number of the units and test them in the field to prove thier work.   Every indication is that the set up will have an impact on the ability of the traditonal traps to attract additional animals to the conventional trap.   The challenge is on the students to prove this and to modify the sound lures to adapt to slightly different component pieces (such as a different sized solar panels).

3D Printed Customised Speaker Box Version 5.0

Above: Design showing lid locking mechanism and cable hole.

Challenge: To produce a weather tight box that could be used to house electronics.
Background: Without sounding repetitive this latest task is a continuation of the process and development for a major creation for our students for a significant national competition.   The essence of it is to have an electronics controller protected against the elements, while also being available for battery changes, modification or repairs as necessary.   The unit needs to be deployed in the New Zealand bush in an area of New Zealand (Taranaki) that has significant rainfall during winter.   This mean the unit needs to be protected against rain/moisture being able to enter and damage the electric circuit.    The unit also needs to have speakers connected to it so they can be deployed outside.   Finally while there needs to be a lid attached to this object that is able to seal it against the elements but allow a light sensor (which is how it will operate) it also has to have the potential to have batteries contained within it.   Ideally a solar panel will be used with this combination however box 1, box 2, box 3,  and into box 4 that are showning development and progression.  Early attempts at the lids

Above; Box shown from above.

depending on development it may be in areas with low level of sunlight which would restrict power options from being used and in this instance rechargeable batteries would be used - so the base of the box needs to have enough space to allow both options.    Design came from the same group of students who have been responsible for all of the boxes in this series.  If you look at the progression of designs from the start of the process the students have perfected the ability to incorporate a design of a locking lid built into the 3D Print design.   Furthermore the other pleasing aspect of the process is that the entire run of prints is being used to one degree or another.  Finally as we have stated before the 3D Printer is the perfect tool for the students to use in this process - it is allowing us to customize the breadboards/chip boards and speaker combination and then build a box to house our potential setup perfectly.  We've been able to demonstrate in the past that the PLA used with the 3D Printers does not weather as we've had outside prints in full weather conditions with no visible signs of any degradation. 
Degree of Difficulty: Medium - this is not for everyone.   The students creating this boxes are a group of ten and eleven year old students who have extensive use and knowledge of the 3D Printers having nearly completed a year in the classroom using them and creating with them.   Little details like dropping down the lid to allow it to lock automatically take a degree of precision to create correctly or the placing of the insert to allow the cable connecting the speakers to the breadboard.

Size: The front of the dimensions of the box measured 80mm wide, 50mm high and the box was 100mm deep.   The thickness of the box (sides) is 10mm.   The insert for the lid to be slid into place was 5mm from the top of the box ensuring that it was strong enough to support the lid.   The biggest potential for the reduction in the box would be the width of the sides of the box - as they could conceivable have been 5mm without compromising the strength of the box. 
Time frame: The base of the box as shown in this box took nine hours to complete.  There was very minimal 'rafting' or waste material this only being the case with the insert where the lid was to be inserted and held in place by the box itself.  It has to be noted however that the sides of the box with this design are somewhat on the thick side.
This has been completed with a 4mm nozzle and a 20% infill.  As has been pointed out in the past on this blog the printers themselves that are being used are now five years old.  One would expect that newer machines would allow a quicker print and perhaps a better quality finish.
What we would do/next steps for students: The student need to complete the lid to complement this design and test this for its effectiveness in wet weather conditions.     

3D Print Customised Speaker Holder

Challenge: To customise a original 3D Printed Box for a speaker.
Background: Since last school term our students have been involved in a significant sound lure project.   This has took a considerable amount of our time and focus.   For this project which is developing at a rapid pace we have recently completed the prototype of the speaker system that we will be using. 

The 3D printer has a crucial role to play in the successful completion of the project as it involves creating an opportunity to water-proof and allow the combination of speakers and parts to be put together.    In this example the speaker (which was a 0.5 watt speaker) was placed in a box that was previously designed as a potential housing box for the speaker system.   The addition of a lid for the box had a significant circular hole

that was built into the lid of the box.   This lid was for positioning of the speaker, which allowed the speaker to vibrate and project a sound that was clear and auidble. 

In this example the lid of the box was only two mm thick as the students wanted to spend time considering whether or not it would work and its acceptable.

This print took fifteen minutes to complete and will be detailed shortly in more depth.  The speaker shown is a recycled speaker.