So first up from @muratdemirbas, "What is the best designed, joy to use product in your life?" And I've got it right here and I bought it in Japan about 30 years ago.

What makes this pencil sharpener special and better than all the ones I've come across? The other ones are plastic and often when you put the pencil in, the thing topples over.

Whereas this is made of cast aluminium so it's very heavy.

And actually it was quite heavy to carry home from the shop and bring all the way back from Japan.

It just works very well, doesn't slip around on the table.

Looks good, has got spots to store pencils in it and it's worked for me unfailingly for 30 years.

The joy of putting this in [motor whirring] and coming out with a lovely, sharp end and the noise it makes, it's just delightful.

This one's from @Rarst, "What is the worst designed appliance you own?" And that's a really easy one to answer and it's a printer.

That next question is from @DougCollinsUX, "Who are your design heroes and why?" Well, one of my design heroes is Alec Issigonis who designed the Mini.

What I really like about the Mini, which is also true of the Walkman, is when they did some research to find out whether the Mini would sell, this tiny car only 10 foot long with tiny wheels, the market research said it wouldn't sell.

Nobody would want a car with silly little wheels like that.

It was just too small.

Of course, ultimately, it became one of the best selling cars in history and was still being made 50 years later.

What I really like about that is that the car he designed looks as good today as it did in the late 50s and that's because it's not styled.

It's the sort of opposite of Harley Earl.

Harley Earl is the sort of designer I hate because it's all fancy wings and it's very showy.

It's design put there to appeal to people to make it sell.

And this is another, and the interesting thing about the Sony Walkman is that it's a tape recorder that won't record.

And that's really, really brave because again they went and asked people, do you want to buy this tape recorder that doesn't record? It just plays back.

And everybody said, no and absolute nonsense, everybody wants a tape recorder that can record.

But Akio Morita at Sony had the bravery to see that actually, although no one says they want it he believed they would want it because they could put it in their pocket and play music with earphones, which no one had ever really been able to do before.

The next one's quite funny.

[laughs] The next questions from @salvatoreDOTcom, he says, "How does suction even like work?" You create suction by developing a very highspeed airflow.

So, you have an electric motor here and a turbine here and if you turn that very, very fast, and we go about 130,000 RPM with that, the air is drawn in to the center here and spun out of the periphery of that turbine at great speed.

And it's so fast that it draws in more and more air, huge amounts of air, and expels them at very high speed and if you're drawing in a lot of air into this device, you're creating suction, so that's what suction is.

Next question is from @JoseOrtega.

"Product Designers, what was your biggest challenge to overcome, lack of experience? How did you overcome it?" Very interestingly I think a lack of experience is a great help.

An expert thinks he knows it all but he's also rather inhibited by his experience, his knowledge, and he finds it difficult to steer off the well-known path.

Whereas if you have a lack of experience but huge curiosity and you approach your new challenge with naivety, I think it's easier for you as an inexperienced designer to come up with something different and to follow a different path.

I'll give an example.

When I started to develop my cyclonic vacuum cleaner separation systems, separating dust from air, I went to the experts and they said you'll never make a cyclone that clears dust out of air below 20 microns.

And 20 microns is a bit too big because a lot of dust is like cigarette smoke, it's half a micron or 0.3 of a micron.

But because of my naivety, I thought, well, maybe he's wrong and I'll try and make it work, so 5 1/2 thousand prototypes later I had made it work and I'd got it down from 20 microns down to 0.3 of a micron.

I advanced the science from being a complete novice.

From @mrs_sloperrrr, "What do I do if I have an invention idea?" The first thing you should do is build a prototype and as soon as you have a product that works, you should then file for a patent.

If you go and file the patent before you've made it work you could get into trouble because a patent has to be of a product or a technology or an engineering idea that works and you have to prove that it works.

And I'm sometimes asked whether you can contract out the making of a prototype to a development company or a model builder or something, and indeed you can do that.

And if it's a purely visual model, I think that's a perfectly good thing to do but if it's anything mechanical or something that has to work, or has a technology that you've got to make to work, it's much, much better you do it yourself.

Because when you come to, and I hope you don't ever have to do it, but you have to fight a patent action, one of the first things that the person you're accusing of copying will say to you, or their lawyers will say to you, did you build that prototype yourself? What they'll trying and argue is that you didn't make the invention at all, it was the person who built the prototype who made the invention.

I also think that the act of making it yourself, actually physically making the prototype, it's vital to do that yourself so you fully understand what you're doing and when it fails, as it probably will, as mine always do, I understand why it's failed and I get an idea as to how I might make it work.

The next one's from @franklagendijk.

"Quick question out of curiosity, what are your biggest challenges currently as a UX designer, product designer or product manager owner?" The biggest challenge is speed, getting a product done quickly.

It takes, nowadays, a lot of people.

You have to have a lot of mechanical designers and product designers but also you have to have a lot of fluid dynamics, motor engineers, software people, ballistics people.

You have to have a whole host of people you didn't have to have 20, 25 years ago.

And increasingly because other countries are developing technology and products so quickly, we've got to compete with that.

So, I would say our biggest single issue is that we've got to do things quicker.

And the next question, which is a bit of a personal one, from @anika4prez, "It's 2021 and how are hand dryers not quiet yet?" Well, I agree with you, I have great sympathy for you, but we're dealing with airflow devices that go at 120, 140,000 RPM.

Any fast turbine moving air is noisy.

Think of jet engines.

When we are designing new generations of hand dryers and we've just brought one out, actually, that's much quieter and we've dropped it down to 750 watts from 1200 watts, so we're getting better at it and you're quite right to complain about it.

From @Sharonica, "A bladeless fan? This is sorcery.

How does Dyson do it?" A bladeless fan came about because we were looking at airflow technology.

If you let out a small blade of air, a very high speed jet of air along a particular surface, actually a surface not unlike an aircraft wing, we noticed that it sucked in from behind it a lot of extra air.

And we did a circular blade, annulars we call it, outlet of air.

Very tiny, it was only a mil and a half wide, and we noticed that it increased the original air flow by 20 times.

In the process the airflow was very smooth, it wasn't interrupted or turbulent.

Whereas a fan with blades gives turbulent air and, of course, a blade is dangerous.

Bladed fans are very difficult to clean.

They have their motor in the center of the fan, so the fan is top heavy and it sort of slumps.

So, we put the motor at the base so the fan was very stable and we had it rotate around its center of gravity, so whatever position you put it in, it stayed there.

So that's really how the fan came about.

It was a very difficult product to launch because when we showed it to people they had no idea what it was.

They thought it was an amplifier of some sorts.

From @LydseyDYoung, "Question for 'Inventors'.

How easy have you found it to get to your product on major retailers shelves?" The answer to that is very simple, it's very, very, very difficult indeed.

They don't know whether your new and different product is going to sell.

In many cases what they'd rather do is just have the same products they've got before but at a cheaper price.

But nowadays we have the internet.

I would suggest that anyone who wants to approach retailers or wants to sell a high volume of their product, should absolutely approach retailers but at the same time and in parallel sell direct on the internet because apart from anything else, if you can prove it sells on the internet, the major retailers would be interested in stocking it.

The next question is from @Moe_offthewall, "How can inventors peacefully carry on innovating when filing for a patent itself costs thousands? This is a headache." Well, I couldn't agree more, Moe, it's a terrible headache.

An individual can't really afford to file a patent and in particular file a patent in many countries but the system is expensive because the examiner has to search through patent offices all over the world, going back many, many years to see if there is a similar invention to yours.

But unfortunately it's the only protection that inventors have and it's the only system inventors have.

It's far from perfect.

It was dreamt up by Henry IV in 1485, I think it was, and it's stayed the same for 600 years and the 20 year life is exactly the same as it was 600 years ago.

So, it jolly well needs an overhaul and it's a system that's desperately unfair for the individual inventor or the small business.

Next question's from @behoff and it's a very interesting one, "What's the most important element of design in your opinion?" So I'm going to give you my opinion, which is very different to lots of other people's opinions.

When I was at the Royal College of Art being taught design, I discovered engineering and I couldn't understand why engineering was separated from design.

Why did you have a white-coated engineer in a lab developing technology and a designer in a separate design studio often completely unrelated to the company developing the product or technology, designing the product? So, I thought design should be part of engineering, like Alec Issigonis with his Mini.

So I see design as being everything about a product from the technology to the engineering to the design to how ergonomic it is, how well it performs and how long it lasts and what materials it use and whether it's sustainable or not.

So I see design covering this whole broad range of disciplines and bringing it all together in a seamless and uninterrupted way.

Well, that's it for now.

They were really good questions, absolutely the right questions to be answering and look forward to next time.

Goodbye.