Posts from — December 2007
I was looking for a new vacuum cleaner recently. Although they seem to be capable, if pricey, vacuum cleaners, I was repelled by the Dyson marketing hype – which seems to play up the lone inventor, who comes up with better ideas for everything he touches. On closer examination, Dyson’s claims seem a little fishy. My information is from Dyson’s web site and this Amazon product blurb.
“5 years and 5,127 prototypes later, the world’s first cyclonic bagless vacuum cleaner arrived.”
OK, let’s think about that:
- Assuming a normal American work schedule, there are about 2,000 work hours per year, so that means Dyson was coming up with a new prototype every 2 hours? (10,000/5127=1.95hrs/prototype). Hmm, that doesn’t make sense. Even assuming 10 researchers, that would be about 20 hours per prototype, which isn’t enough to design, make, test, and evaluate.
- But Dyson had trouble making his patent renewal payments (currently starting at Â£140 per year per patent, after the fourth year), so I don’t think he was paying 10 people. So we’re back to 2 hours per prototype – yeah, right!
- Elsewhere the hype implies three researchers – so that’s 1 prototype every 6 hours! But I wonder why, if Dyson could pay two other researchers, why he couldn’t pay the much smaller patent renewal bill?
- I think 5,127 prototypes is supposed to impress people. It doesn’t impress me. If you are truly engineering (and not tinkering), you shouldn’t have to do that many prototypes. Fluid flow principles haven’t changed recently. Admittedly, it’d be easier today (with fast computers and affordable simulation software) but even in 1978,with a calculator and good engineering knowledge you could do a lot.
- There’s a whole area called DOE (Design of Experiments) that is about minimizing the number of experiments you need to do. Good result analysis (matching real results with predictions) also results in fewer wasted prototypes – and deeper understanding of the problem domain.
Dyson likes to talk about their reliability.
But a UK survey showed they were the only brand with below average reliability.
“Only Dyson doesn’t lose suction
Dyson Root Cyclone technology uses 100,000G of centrifugal force in the cyclones to filter dust and remove dirt from the airflow efficiently. Because there is nothing to obstruct the airflow, it doesn’t clog and doesn’t lose suction.“
But the Dyson definitely can clog – here’s one way to clean it. The pre-motor filter needs washing every six months.
“The original team of 3 Dyson engineers grew to 350 scientists in a new research center, …”
I’m not too impressed – 350 R&D people (I doubt most are really scientists) to support a product line of pretty similar upright vacuums, a canister vacuum, a hand held vacuum, a clothes washer, and a hand dryer. Maybe that’s why the machines are made in Malaysia, unlike similarly priced machines from Bosch, Miele, etc which are still made in Europe.
My vacuum cleaner thoughts:
- Dyson probably makes good vacuums – I’ve seen too many positive comments. However, I do think they are over-hyped.
- I went with a canister vacuum, because I wanted something light (so my wife could use it), quiet, variable speed, and that could easily reach under furniture. I bought a bagged Bosch canister vacuum; so far I’ve been very happy with it. The Dyson canister vac was out when my wife heard the price.
- My old vacuum was a non-Dyson upright bagless. Its filters most definitely did clog eventually; maybe Dysons are better about that. There is definitely some convenience to the bagless, and it’s very nice to see all that dust swirling around.
- I think my new bagged vacuum cleans better than my old bagless – for one, the dust is fluffed up with a bagless so it looks impressive, but when you scrunch it down, you don’t have much.
Comments 4/20/2011: I’m still skeptical about the Dyson hype;Â Machine Design (if I recall correctly) ran a puff-piece on Dyson a few years ago that explained a few things, but still left me with lots of unanswered questions.
My Bosch is still going strong; the only problem is that I can’t buy the bags locally, but I’ve found some good quality, affordable third party bags on the internet (they’re cloth like the Bosch bags).
December 13, 2007 No Comments