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Dyson DC07

11th August 2016

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Introduction

The Dyson DC01 is undeniably one of the world’s design classics, with James Dyson being one of the most recognised faces of the modern design world. After reading Dyson’s autobiography “Against the Odds” and learning about the story behind the development of the Dual Cyclone and his focus towards making a product that would out merit it’s competitors in every aspect, I was intrigued to analyse the smaller components that come together to create such a fantastic end result.

What is interesting about this DC07 model is that it was the first Dyson to include the improved “root cyclone technology” which builds upon the concept of the Dual Cyclone and uses it to provide higher, more continuous suction power. The Dual Cyclone finds the balance between precision engineering and beautiful design and as my understanding of it has progressed through intially reading about it’s development, to then analysing countless diagrams and Youtube videos, it feels only right that the next step will be to see the inner workings for myself.

Cleaning

I shall not spend too long on this section; but I feel like it is deserved of attention. Due to the nature of the product, the first step of this teardown was to eliminate all the dust from the components to hopefully avoid dramatically shortening my life expectancy. I have to say that I was immediately reminded of why I admire Dyson’s attention to detail so much as I was able to clean the entire product without removing a single screw or dealing with any nasty snap fits: the majority of components had both handy release levers and clear signifiers; but we shall focus more on these later.

With the product now clean, I decided to break it down into more manageable sized sections.

The removable bin - being a component that is praised for it’s ergonomic qualities and functionality - was the easiest; thanks to it’s simple release mechanism.

Something became apparent to me when removing the hose attachment. The helpful rung for looping the flex round doubles up as a handle that affords lifting to easily remove the attachement from the upright section.

Collection Bin

As one of the key features, the collection bin shows the most obvious signs of being designed with the user in mind: The removal mechanism which was already mentioned, the easy carry handle and release trigger all display a design process the places the customer at it’s core.

Trigger Extension Mechanism

We now see the rod that runs through the centre of the cyclone and how it extends to push open the bin lid. This extension is achieved by a simple pivot arm on the release trigger and the feedback is achieved through a spring on the rod.

Dual Cyclone

We hit a problem!

After removing the internal screws which appeared to be holding the Root Cyclone arrangement on top of the Dual Cyclone, then struggling for a fair amount of time and destroying a hammer! I found that my original thinking that the DC07 would be a good model to perform a teardown of had been misinformed. After scrolling through a cyclone disassembly forum, I soon found the statement “The only one you cant get completely apart is the DC07 as its glued together…” not so great for a teardown.

Basic Makeup

With a fair bit of force I am able to remove the shroud from the cyclone which helps to define the boundary between the two cyclones: catching larger bits of debris and allowing the smaller dust particles to continue into the internal cyclone and be further accelerated.

Entry Point

From what I understand about how the cyclone works, one of the most influential factors is the point where the air and dust enter the cyclone. Fortunately this occurs at the entry point of the transparent bin so I am able to display this. This section is intriguing as unless you know how the cyclone works, it appears to be one of the simplest parts of the whole product, when intact this entry point is the result of over a hundred prototypes during DC01 conception and has then been refined further over various models.

We should take a step back from the teardown here to realise what this attribute stands for in terms of Dyson’s design process. It is continuously mentioned in his autobiography how he has never been a fan of designing by means of mathematics and physics, but for this component, he was given no choice. He explains that, although it is possible to construct an equation for particle behaviour in a cyclone, you cannot do this when there are a thousand different particles sizes to be taken account of. This is where he applied his raw design approach where in absence of formulae you have to adopt the Edisonian method and test, test until it works best. Dyson concludes his explanation of the entry point with a statement which I feel summaries the entire design process and also reiterates my point on why the extremely simple appearance of this aspect is not proportional to it’s complexity.

“Because it is such a simple principle, it is also a ludicrously complicated one: so many factors affect it’s efficiency”

Although I am unable to dissassemble the Dual Cyclone it would be unfair to abuse the component so I will try to give a quick overview.

1. Firstly, Air and Dust are sucked into the bin. Here, when the dust comes into contact with the curved surface its speed is multiplied 3 fold and it is exposed to centrifugal force - increasing the mass of the dust - making it more susceptible to gravity. The parallel sides of this first cyclone came about through Dyson’s discovery of two cyclones being better than one, in that larger objects don’t need accelerated so dramatically to increase their mass, so are taken care of in the first cyclone.

2. The fins on the inner cyclone slow the air and force it to flow upwards through the channels to the shroud. Here the smaller dust particles are pulled through by the extra suction of the root cyclone and large pieces are left behind to be handled by the first cyclone.

3. The next stage deals with how the mixture enters the second cyclone, which is unfortunately the bit I am unable to access.

Hopefully the sketch illustrates that the mixture enters and is accelerated even more rapidly than before due to the fact that when you reduce the diameter around which the dust is travelling it will accelerate further.

This then leaves the clean air to flow upwards out of the cyclone and be sucked away by the increased flow produced by the inverted cyclones in the Root Cyclone arrangement.

4. With the dust falling down into the collection bin the clean air is then sucked out through the exit point and is carried down to the base of the product.

Motor Enclosure

If we continue the teardown by following this airflow, we encounter the filter that prevents any leftover dust from entering the motor. We see here that Dyson have included a removable (and re-usable) filter that is simply cleaned by running it under a tap. There is also an interesting arrangement within the filter that uses a rubber cap, spring and locking piece to create an air tight seal.

The stage that I had already gotten this part of the product to didn’t really disclose much of it’s workings and it definitely seemed as if the motor was going to be difficult to reach.

After removing a few more screws and prising bits of plastic apart, I am able to release the motor from it’s casing.

When we remove all the internal casings from the motor we see that even with the efficiency of the Dual Cyclone and the filters that precede the motor, there is still a certain volume of dust that has reached the motor. Although, considering this cleaner had 10 years of frequent use in a farmhouse this is only a fraction of the dust that would have passed through the system.

Now, for some reason the screws that hold the fans cover on appear to be screwed in from the wrong side: meaning that I am unable to remove the cover. After looking up the motor  all these images have the screw heads facing upwards.

I am able to remove the carbon brush assemblies and see the spring arrangement within them.

As I am once again stumped by the unfortunate construction of the DC07 I will attempt to show the important elements of the motor through the following photos.

Firstly, an interesting and important component is the Thermal Cutoff Unit which helps to prevent the motor from overheating. This is located between the power inlet and the connection to the carbon brushes; ensuring that no current can flow into the motor if the threshold is reached. After looking up this unit, I find that it is an auto-reset protector meaning that in theory it should return to it’s inital state of allowing current to flow once the motor has returned to a suitable working temperature. Having seen how difficult it is to access this component the idea that it should never have to be replaced is very advantageous.

Next we encounter a rather large capacitor which helps provide interference suppression for the motor - eliminating disturbances from external sources - that affect the internal electric circuit.

This connection then links the power source to the actual motor.

If we then look inside the housing we can see the Commutator which would obviously be in contact with the brushes and below that - which is rather difficult to see - the armature, wrapped in an abundance of copper wire.

Brush Assembly

We reach the sub-assembly of the product which contains the brush component and tube that conducts the flow into the cyclone.

If we first look at the driving mechanism for the brush I initially notice the belt drive that effectively connects the brush to the motor. Hopefully the exploded view shows a little more insight into how this connection is made.

The actual brush itself is a reasonably simple component, apart from the helix arrangement of the bristles which attempts to prevent objects becoming jammed as only a small section of the brush touches the floor at one time. It is probably important to point out here that this component - similar to the cyclone - is one that could only be optimised through physical testing.

I think the last area - that effectively completes the cycle - is the route that the mixture of dust and takes to make it from floor to cyclone. The mixture is carried through the tube and then diverted into the vertical pipe that leads to the entry point on the collection bin.

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Conclusion

This teardown has been a mixed experience with many components being extremely easy to remove and others causing me stress and resulting in minor injuries whilst trying to separate components.

I began this post by stating that I hoped this teardown would develop my understanding of the product - and while it has by allowing me to see how each component is connected together - what has really allowed me to learn more lies in the process of constructing the post. What has hopefully been achieved is that I tried to explain each area in a way that would allow the reader to fully understand each component and to do this I had to ensure that my knowledge was justified by carrying out further research and returning to Dyson’s autobiography on multiple occasions.

Overall this process has showed me why a Dyson really is that much better than it’s competitors and why - I feel - that it’s price tag is justified. To take this appreciation further I think the next step would be to deconstruct another brand of vacuum cleaner; possibly an Electrolux or Vax after hearing about Dyson’s battles with these companies during the inception of the Dual Cyclone...

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Copyright © Duncan Pattullo 2017