Stage 1: Preliminary Design
Week 1
“Balance” has decided to change our project away from our original self-balancing robot proposal. Now “concentric”, we will attempt to prototype a novel cleaning device with practical household applications.
To analyse the inner components of a typical vacuum cleaner, Karn took apart a spoilt one, and even managed to salvage a dc motor and potentiometer for reference!
A preliminary prototype of the nozzle to be attached to both the vacuum and high pressure air jet was modelled using Autodesk Fusion and printed. Here was our initial design:
The design included an inlet tube for high pressure air to go through, placed concentric to a larger tube. The larger tube served as the outlet, to be attached to a vacuum.
Week 2
As a preliminary proof-of-concept, the nozzle was tested by being attached to an existing vacuum cleaner, and a high pressure nitrogen source present in the MnT lab. Cleaning of a dusty keyboard in the lab was tested. Shining a torch on the cleaned area showed that with the vacuum alone, little dust was being sucked up, while when the nozzle was used, dust could be seen visibly detaching itself from the keyboard and being vacuumed. This rough visual analysis proved to us that this two-in-one concept would likely be feasible.
The focus of this week was learning to make use of the tools needed in this project, so Kimberly started learning Fusion 360. In the mean time, coding for the control system by Karn and Chiah Soon had begun, with preliminary CFD for the airflow through the designed nozzle being conducted by Karn as well. Yi Shiuan was away in CERN during the week.
Week 3
Actual prototype design occurred this week. Kimberly was in charge of designing the user handle to be used to on/off the vacuum, while Yi Shiuan and Chiah Soon worked on different nozzle designs meant to increase versatility. Details of the designs can be seen in design specifications.
Chiah Soon and Karn also continued working on the coding for the system, which included the control of the solenoid valve to trigger the release of the high pressure jet stream. Karn also worked on the electronics of the system.
A powerpac vacuum cleaner was bought as a base template for our design, where the cleaner was dismantled and the motor and vacuum are to be directly used in our final prototype design.
Stage 2: Overall Product Design and Assembly
Week 4
Electronics assembly began this week, led by Karn. Here’s the schematic and real life assembly in progress.
Yi Shiuan and Chiah Soon continued to refine their nozzle designs based on the limitations of their test prints. Yi Shiuan also started working on the CFD to simulated air/dust flow into the nozzles.
Preliminary CFD results showed that the current large tube of the nozzle is too small, such that the dust being sucked up by the vacuum is largely restricted. Sharp edges were also present in the design (especially the 90 degrees head design), and much turbulence was seen especially at those areas. These were learning points that were very crucial in helping us improve our designs, for greater optimisation of airflow.
Kimberly started working on overall product design for the final prototype.
Week 5
We have started assembling our vacuum together. All our parts – the nozzle and handle are printing right now as I am typing. Almost everything that is needed for assembly has arrived. The aluminium frame has been cut and is currently being assembled. (code button thingy here :)).
The code has been written to allow for the pulsing of the air-jets in customizable time intervals (by varying the solenoid valve) within a predetermined range, using a 3-button switch to be fitted on the handle itself.
CFD was done but it still failed, due to time constraints, we will be working towards physical experiments soon instead of using CFD.
Week 6
The aluminium frame has been assembled and we are left to edit the code to control the air compressor and vacuum and carry out physical experiments. The physical experiments are to prove that our concept of our vacuum that can blow and suck is better than the conventional vacuum in cleaning harder to reach areas such as grilles.
Below shows our current aluminium assembly.
As seen above, our air compressor, vacuum and electrical appliances fit in the aluminium frame and this frame is fitted with caster wheels for ease of movement. Our handle design has also been updated and now comes fitted with 5 different buttons/switches that controls different things.
The main switch turns on the whole system (vacuum and air compressor). 
The up down buttons control the pulsing time for the air tank valve and the round button turns off the air compressor. The levered switch serves to allow the user to shoot air out of the nozzle.
Preliminary physical experiment: Currently using flour and water to make a dough like mixture that is hard to remove in a plastic container.
Week 7
Our group is busy printing compartment boxes to cover and protect our electronics such as the arduino and the raspberry pi. CS is currently working on the LED display of the handle. There is also reassembly of our vacuum cleaner to make its structure more compact. Our experiment from flour and water will be altered to using styrofoam balls instead. The cyclone for our vacuum has also arrived. This cyclone will help our vacuum cleaner to filter out the dust.
Above shows our progress with assembly~ Almost everything is there except we are waiting for the part for the dust box to be printed before we can assemble everything together into this more compacted frame. Furthermore, you can also see that 3D printed parts were made to cover our electrical appliances like the mains, the raspberry pi and arduino and the relays. Even the motor!
On the right shows our cyclone with the dust box beneath. The dust box was made of acrylic and 3D printed parts. This cyclone will help to filter the dust sucked in by the vacuum to ensure that only clean air and not air with some dust will flow out. The cyclone works like a centrifuge. As air is sucked in by the vacuum, it moves like a cyclone and the heavier dust is separated from the air and moves down to the bottom of the cyclone separator, falling into the dust box. Cleaner air is then released back to the surroundings.
Week 8
We’re left with the last touch-ups for this project (we’re trying to assemble everything right now and find out what issues we have). The right shows our whole set up! As you can see, our internal wiring has been cleared up and everything is being boxed up for protection.
LED screen has been updated to show both air pressure and time interval for pulsing (as seen in the picture below). The up and down buttons increase/decrease air pressure and time interval for pulsing, while the round button toggles between air pressure and time interval (as seen in the picture on the right).
A safety feature to release all air in the compressor out when the vacuum is turned off was also added. We are currently working on touch-ups for the vacuum. However, the hardware is mostly done. All that is left is some minor improvements to the nozzle head and software improvements. Lastly, we are left with beautifying the vacuum (if possible).
Of course, not forgetting our physical experiments. So far, we’ve experimented with cleaning the aluminium cutter from the MnT lab. I’m sure you’ve seen the videos from the progress meeting. The videos are also included below. (They are links as they are pretty huge files)
Flat surface with only vacuum: Video
Flat surface with vacuum and air blower: Video
As you can see, the blower works very well with the vacuum to clean the aluminium cutter (flat surface only). Thus, we are improving on our nozzle meant for corners.
We are also currently working on better ventilation for our raspberry pi so that the sd card does not overheat and get fried. (2 SD cards have already been sacrificed 🙁 )
Week 9 – 10
We are now making sure that we have extras of every component incase they fail. Currently, we are only doing minor optimisations in preparation for the exhibition and our presentation. The vacuum blower is mostly completed!