Introduction: Pocket Sized Vacuum Cleaner
Hello everyone, hope you guys are having fun around DIYs. As you have read the title, this project is about making a pocket vacuum cleaner. It’s portable, convenient and super easy to use. Features like additional blower option, in built nozzle storage and external power supply options takes things to a better level than a normal DIY vacuum cleaner perceptive . The total build process was very interesting and challenging for me since it involved different fields of work like Electronics, cutting and heat molding of PVCs, certain aspects of crafting, upholstery and few others. So, let’s dive into the build! Shall we?
Step 1: Dust Container
The dust container serves two purpose. One, to reduce the casing diameter (nozzle). This helps to increase the suction velocity at the end (venturi effect). Second, it helps to collect the dust during the suction process.
Its made from two PVC pipe fittings. A 2 inch PVC coupler & a 1.5 inch to 0.5 inch PVC reducer. The length of the 1.5 inch side of the reducer is taken as 1 cm and the rest is cut off using a hack saw. A 0.5 inch pipe is temporarily inserted to the other end such that it extends to a length of 1cm. This side is kept as bottom and placed inside the 2 inch PVC coupler. Previous 1cm PVC extension helps to raise the reducer in order to provide space for the Nozzle storage option which we would discuss at a later stage. Now, using a drill of appropriate size the dust container and the inside reducer is drilled. Please note that we are drilling to the 1.5 inch side of the reducer. Similarly, 4 holes are drilled in order for bolt insertion and fixing. The remaining air gap inside the section is then sealed by epoxy putty. This finished the dust container. Let’s move on to the next.
Step 2: Electronic Components
A total of 5 electronic components were used for the required functions. They are mentioned below.
1) Constant current/Constant voltage buck converter module
2) 1S battery management system board (BMS board)
3) 18650 LI-ion cells ( 2 of them are required)
4) Charging module
5) 40,000 rpm DC motor
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We’ll now discuss each components in detail below.
Constant current/Constant voltage buck converter module
Even though we could drive the DC motor without out this module, adding this module is a makes our vacuum cleaner more flexible. The motor we are using consumes around 4.2 A at 7.4 V. In our case we are using the two Li ion cells in parallel the maximum we could get is around 4.2 V and would drops to 3.7V and then to 2.5V where the circuits kicks in and cuts off further discharge. While testing the suction, I founded out that a current of 3A for the LI-ion cell does a good job. So going to a higher 4.2 A is not that efficient and more over drains battery much quicker. So the required current draw of 3A is controlled using this module. On the other hand, setting the voltage level to 7.4 V with the module helps us to use any DC adapter below 30V output. It would be automatically stepped down to our required 7.4 V all the time and thus provide more usage flexibility.
1S battery management system board (BMS board)
The BMS board provides the over & under charge protection for the Li- ion cells. The charging board itself is capable of provide this function but it’s rated up to a maximum limit of 3A. Pushing the circuit to its maximum limit not being a good design practice, I used a separate BMS rated at 10A for this function.
18650 LI-ion cells
Two of these cells are used in parallel for a higher capacity. Make sure that each cells are fully charged individually before connecting in parallel. Battery with different voltage level when connected in parallel, leads to rapid uncontrolled charging of the lower cell by the higher cell and thus not recommended.
Using the charging module is pretty much straight forward. Since we are using a BMS at the output side, the output terminals on the charging module are left alone.
40,000 rpm DC motor
A typical vacuum cleaner actually runs much below 40,000 rpm. So why did I go for a higher value? Well, those ones are much bigger than the one I build. This is in favor of using a larger and wider impeller for the required suction. But in our case, size was the most priority and it should be small enough to fit inside a pocket. So using a larger impeller was not our option. In order to compensate this limitation, I went for a higher rpm motor. The one I used is a RS-370SD DC motor which has a rating of 50,000 rpm at 7.4V under no load condition.
Step 3: Impeller
Impeller is the main part of our project. It’s the thing which creates the suction and blower option possible. Since the impeller is rotating at a very higher rpm, unbalanced weight of the impeller at any point would add up to the vibration of the entire structure during its working. Also, it must be designed strong to withstand the rotation at such high rpm. If you have seen other DIY vacuum cleaner projects, you would be familiar to the process of cutting metal sheets to make the impeller. It’s a good technique but often the impeller would be unbalanced in weight distribution. Taking into account of our previous problem with the vibration I dropped this method and instead used a DC cooling fan as impeller. However, these fans are designed to be out runner motors and we can find a proper center for attaching it to the motor shaft. So a separate plastic toy fan is used as a connection point. The leaves of it were chopped off and the main central portion is retained. This is further fixed to the impeller using epoxy putty.
Step 4: Component Casing
The component casing conceals all the electronic components mentioned above. This rectangular piece of casing is made by heating a 1.25 inch PVC pipe using a heat gun. To acquire the required shape, first I made a die from a plywood section. It has a width of 5.5cm, length of 16 cm and a thickness of 2cm. This wooden die is inserted into the PVC pipe after heating it thoroughly. After cooling, the die is removed. What we have now is a rectangular hollow casing open at both ends. One of the ends is heated again, cut and folded over to close that side. This completes the component casing.
Step 5: Component Casing Top Section
This part contains the micro USB port for charging, the DPDT switch for toggling between suction and blower function and a DC socket for powering directly from DC adapters. This section is made from a small strip of PVC pipe. BY warming it with a heat gun and then applying pressure on top of it, it’s brought to a flat piece. The open end of the previously explained component casing is placed above it and the outline is traced with a marker. Further the sides of the section are again warmed with the heat gun and folded inwards such that this section act as a top covering for the casing. Now we are done with the basic shape and next step is to cut necessary openings on top of this section so that it could accommodate the socket and switches. I used a drill and pointed end of a hot soldering to do this task. Now the sockets and witch are inserted and to fix it in place I used some epoxy putty. Make sure that the pins are well exposed and not covered by the epoxy. This finishes the top section and we’ll come back to its installation at a later stage of build.
Step 6: Main Body
The main body encloses the electronics, motor, impeller, switches & sockets. It’s made from a 2 Inch PVC pipe of length 23 cm. The length depends on the size specifications of other components used in the project. Hence this 23cm is only a round estimate for my project. Hence it’s much better to build this main body towards the last of build.
At the front, the motor and impeller should be fixed using two L clamps. First, the L clamps are fixed to the motor body and wires are soldered from the terminals. I have used a standard 1 inch L clamp for the purpose but cutting and tweaking of the L clamp would be required to properly fit it inside the main body. Once that’s done, we could drill corresponding holes on the front end of the main body PVC and insert the whole motor and L clamp setup inside the main body. It’s attached to the main body using bolts. I have used a standard 1 inch L clamp for the purpose but small cutting and tweaking of the L clamp would be required to properly fit it inside the main body. While fitting the L clamp, keep in mind to leave a small space at the front (around 2cm in my case) so that the dust container could be inserted at a later stage. Since the impeller is designed to be push fitted on the motor shaft, we could do that at a later stage of build. So let’s move on to the rest.
Step 7: Fixing the Circuits on Glass Fiber Sheet
I have been following this technique in most of my projects. The main reason is the flexibly and convenience it gives in placing circuit components. Most of us using electronic circuit boards would be aware of the fact that, a lot of them don’t comes with a proper way for screw fixing firmly on a surface. Have been dealing this issue for a long time while doing DIY projects. Finally I thought of using a piece of glass fiber sheet and fixing the circuits over it using zip ties. Firstly, a piece of the sheet is cut according to our requirement. Then, the circuit boards are arranged over it such that it uses the space effectively. The outline is traced with a marker and Couple of holes are made around these outlines. These holes are used to insert the zip ties for fixing the circuits and could be made by piercing with a hot soldering iron tip. Before fixing the boards, wires are soldered from all the terminals of the circuit boards.
Step 8: Modifying PVC Casing and Main Body
This step includes cutting slit for the on off switch, drilling hole for casing attachment and cutting slit for charging indication light. First, insert the PVC component casing into the main body until it touches the motor at the other end. Also make sure that the casing is a bit tightly fitted inside the main body. Using some double sided tape outside the casing could help to get a tight fit while inserting the casing. Then using a hot soldering iron make a slit for the main on/off switch. The slit should pass through the main body and the casing inside it. Then drill a through hole for fixing the casing at a later stage using a bolt. Once it’s done, we could remove the casing from the main body. The top switch section is now inserted onto the casing and the same holes drilled on its 2 legs. Once it’s done we could insert the circuit components (layer over the glass fiber sheet) into it. Then the top switch section is connected and soldered according to the wiring diagram that I have provided in this step.
Step 9: Dust Mesh
The dust mesh acts as a strainer between the impeller and dust container thereby collecting all the dust particles within the dust container. The outer casing for it is made from a 1.5 inch PVC end cap. The closed side is cut off to get a ring like structure. Then, a metal mesh of appropriate size is folded over this newly cut side. It’s further fixed properly by drilling 4 holes on the sides and then fastened with some bolts. This section could be later inserted at the front side of the main body.
Step 10: Upholstery Work
Most of the processes would be clear while watching the video. So I’m not explaining thing in detail here. I used a black jute cloth and synthetic rubber adhesive (rubber cement) for the upholstery work. Bothe the main body and dust container are covered properly with the cloth. Let’s move on the next.
Step 11: Final Assembly
The previous component casing is now inserted into the main body. The two wires from the motor is now soldered to the respective terminals. All the further wires are taken out through the on/off switch slit. The top switch section is now pressed over the casing so that all the holes get properly aligned. A bolt is now inserted through these holes and thereby fixing the casing and top section on to the main body. We could now move on to the final set of connecting the on/off switch on the side. Refer the wiring diagram for it connections. Now we could inset the impeller, dust mesh and the dust container at the front.
Step 12: Nozzle Attachments
As mentioned at the beginning of this article, In-built nozzle storage is good feature of this vacuum cleaner. We have already left space for the storage while designing the dust container. Most of the things are clear from the video tutorial itself. All nozzles are made from 0.5 inch PVC pipes. It’s heated to attain different size and shape. I have also added a small brush at the front of one nozzles for easy dust removal. The brush are taken by breaking a hair dye brush and then gluing inside the nozzle using epoxy adhesive.
To cover the front opening of the dust container, I have a piece of the same jute cloth that have been used in the previous upholstery work. Using a Velcro attachment as shown in the video, it’s fitted at the front.
So this completes the build. Let me know your thoughts in the comment section below. See you guys in my next project.
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