the price over a mass amount of units (say 100,000 units)
This almost made me laugh out loud. Exactly how many kettles does the author think sells each year? Multiply by models and again by manufacturers, and you're talking millions of kettles. Even if you consider that one model will last multiple years, manufacturers don't buy supply batches that last for years. Some industries go in the extreme other direction - the local car industry got its stock-on-shelf lifetime down to 48 minutes from part arriving to part being screwed into car.
Similarly, retail markup is generally 20-50% of the final cost. If you think this is too high (it really isn't) then I suggest you use your new formula to undercut the existing market and disrupt away. Other significant costs are transport and wholesalers (who aren't always the manufacturers). Kettles are bulky items that consume a lot of space in storage and transport. On top of all this, every party involved in the transaction is entitled to make some profit, and not just work for costs. There's also regulatory compliance, things like the CE mark.
Looking at an item and stating that the price shouldn't be more than parts + amortised kickback to the designers is naievity, plain and simple.
Say 10% of American households and 80% of British households buy electric tea kettles that last exactly 10 years each.
That's 10 million total market in the US (100 x .1) and about 16 million in the UK (~20 x .8).
So 26 million total market with a level 1/10th per year or 2.6 million kettles per year. At 100k run per year per manufacturer, the market can then support 26 different models easily.
On the second point, It seemed that he was adding the 2x retail markup into his figures. If you'd followed the link on amazon, you'd see that $90 was market down from about $200.
Sometimes it's best to ask "what would you have to believe for this to be right" before you tear into someone for faulty analysis. All of his number easily pass my smoke tests.
I thought that markup was implicitly accepted in blog. I of course do not think that the price should be just the cost of the parts. In fact, I did mention that the fact that both $10 kettles and $39 kettles exist implies that there is some form of price discrimination. The difference in price is the additional markup that the manufacturer can get away with. As I mentioned, my marginal utility does not increase with the markup - a $39 kettle gives me the same utility as a $10 kettle.
As for 100,000 units, yeah, that was probably a mistake. Australia only has 22 million people. No idea why I arbitrarily picked 100,000.
Do you have a source for the part about 48mins from part arrival to installation? I find that data point fascinating and would like to learn more about how this is pulled off.
> "The kettle had caused the trip. It was no longer safe to use the kettle"
> You know enough to start designing a temp. controlled kettle, and yet you overlooked the simple (and most likely) possibility that the kettle was on the same circuit with another high draw appliance (hair dryer, electric heater, etc.) and the combination of the two resulted in the trip from overload. And that there was nothing in fact wrong with the kettle at all.
We sometimes forget that our hacker minds can be a weakness :)
Bear in mind that the price of insurance and UL certification is also built into these devices. Heat, huge amounts of electricity, water, hands: lots of liability.
Is PID control all that expensive? Aren't you talking about a microcontroller, a thermocouple, and a relay?
I was surprised he didn't take these into account. Not to mention quality control, or accounting for market fluctuations in price and manufacturing costs. The price is calculated to be a reasonable bet to pay for periods of really high costs from profits in periods of low costs.
Quality control in a typical product is really a bigger deal than most hackers think. He didn't account for the fact that if you go to china or hong kong and contract a manufacturing organisation to build your kettle, it's very likely you'll get your first shipment, coming in on your boat or plane and half the kettles are dead or defective or dangerous on arrival. There's nothing to do with those but throw them out, or maybe sell them back over to india for recycling, and the cost of those lost sales is built into the price of the not defective kettles.
The maths here assumes you have no shipping costs and no defective products, no manufacturing problems and no price fluctuations. Doesn't seem very realistic.
I once worked on a device that needed UL certification. It was $50,000 per test cycle, so the motivation was there to get your product right before submitting it.
Why does the author seem to think that a digital solution is required for control over temperature?
The bimetallic approach can be extended to select temperature. An analogue dial can adjust the switch cutoff position (or alternatively, the starting angle of the bimetallic strip) with a screw. All you'd need to do is calibrate the dial, and the added cost shouldn't be more than 50 US cents on the end retail price.
IMO the reason a "good" kettle costs $90+ is because there isn't enough demand to create enough competition and support enough production to amortize the fixed costs. It's essentially a market broken apart into two of Porter's three fundamental strategies, cost leadership and differentiation. The cheapest kettles would be uncompetitive with a temperature selector even if it added only pennies, while the differentiated kettles have specific features for smaller, less cost sensitive markets. Most people simply don't need temperature selection.
I believe the reason he's going for a PID is the ability to reach the target temperature without overshooting. A PID would gradually reduce the power to the heating element as the temperature get closer to the target.
That said, the adjustable bimetallic solution is certain worth a try, it might just work good enough and be far cheaper and much more reliable in the long run.
Digital thermostats work on electrical resistance which is more accurate than bimetallic thermostats. Also bimetallic thermostats basically only switch at one temperature whereas most digital thermostats can handle a range. If you intend on using a kettle for both coffee and tea, that range is desired since the ideal temperatures between coffee and tea is quite significant.
Your electric kettle almost certainly uses a thermostat patented by John Taylor [1], who made his fortune with the things. Effectively, your kettle helped pay for the wonderful Corpus Clock [2] - 'the strangest clock in the world' :)
People here are forgetting that you can buy a fully functioning tablet on a retail shelf for less than the cost of a temperature controlled kettle. You can buy a tablet AND a conventional kettle for less than the cost of the temperature controlled kettle. Tablet makers have to deal with QC and retail markup and all of the other things mentioned in this thread as possible drivers of the price so I don't find many of the explanations convincing.
In reality, it's likely that either a) these things are being sold at massive profit margins or b) they're being produced very inefficiently with lots of waste in the production process.
I think a lot of cheap tablets are loss leaders, and the manufacturers don't make any profit (or even lose money) and hope to make more money by bringing them into their retail stores (eg Tesco, Walmart tabs) or on accessories.
That said, I think the kettle thing is mostly a). Companies will price things highly because they've found that people will pay that much, I reckon it's as simple as that.
This is not correct. The boiling point of water is a function of atmospheric pressure [1]. Weather changes the atmospheric pressure by up to 50mbar, which translates to a couple degrees of variation in the boiling point.
The pressure variation due to height is even more severe [2]. At an elevation of 3000m the atmospheric pressure is typically only 700mbar, which means that water boils at 90 degrees.
How does the basic bimetallic strip know the outside pressure and the boiling-point-curve of water so that is knows when to stop the kettle?
I don't think it knows anything about that. Instead I assume once the water starts boiling, the bubbling steam-"padding" around the heating element lowers the heat transfer rate from the heating element to the liquid. This means that the heating element will quickly get a lot hotter until it reaches the threshold temperature of the bimetallic switch.
Thermodynamics was never my favourite subject, but I suspect what happens is that the water boiling at the lower temperature created a higher pressure within the kettle (hence the screaming noise as pressure escapes the small nozzle), allowing the water to heat up to 100degC, and also the bimetallic strip.
Interesting. I was also wondering about this; how the kettle knows what the boiling point is, since it cannot just measure temperature, because it would boil out the water in the mountains.
I thought there is electronics which simply detects not only absolute temperature, but also change. Once the temperature stops changing and is around 100 degrees, it will stop.
I read the article and most of the comments and I still can't figure out why on earth you would care how hot your teawater is, beyond "boiling"/"not yet boiling." All my life I have made tea with a ~$10 stovetop whistling kettle; no one has ever criticized it and it will never break.
Different tea varieties are best at different temperatures. It doesn't matter much if you use generic black teabags from the store, because the tea is usually quite old has lost most of the subtle tastes.
White, green, oolong or really any kind good black tea might require less than boiling temperatures to extract enough out of tea while preserving the taste or other wished effects of the tea. The temperatures, amount and the steep time might be different by each specific tea or batch.
So a kettle with a temperature control can be helpful and save time with tea or cooking if you want finer control than boiling - not boiling.
So, for tea at least, and green tea in particular, water temperature is actually very important. This is often overlooked by people (at least in my experience in America). I've had many friends who claimed to hate Green Tea because it is bitter. But they changed their minds when I brewed them a cup and explained that it is important not to burn the leaves with hot water and then over-steep the tea---rather than boiling water you often want water considerably cooler, say 150-180 F, depending on the tea. You also don't want to steep for too long (often just a minute or two, again depends on the tea).
Different teas require different water temperatures AND different steeping times for the best taste. Generally the less oxidized the tea the lower the water temperature. I find the worst offense is most Americans over steep their tea which makes it very bitter!
People who use a thermometer are very serious. I just guesstimate.
Also, get some high quality tea, the difference in taste is amazing and its not that expensive, only a few cents a cup.
Depending on how "into" tea you are, various teas require steeping for a specific duration of time under a specific temperature. See a website he mentions, steepster.com, where people talk almost exclusively about this topic.
Add a thermometer to the stovetop kettle and it'd be perfect! :-) I would much rather boil water with gas. It's cheaper and there's no risk that it will overload the circuit breaker.
Buy a container worth of kettles, register goodcheapkettles.com, sell them for a year, and this question will answer itself. Probably cheaper and more useful than studying business in undergrad.
I don't think a good kettle has to cost $90 - There's one one amazon with 80% 5 star reviews for $20. http://www.amazon.com/Courant-Cordless-Electric-Coffee-Maker... . Still there are lots of wealthy people with $100 + to spend so manufacturers will naturally make stuff for those price points if customers will buy it.
I had an expensive kettle which was a gift. It lasted ten years but then started to leak and finally started tripping the breaker. I replaced it with a $20 plastic kettle which does everything the other one did, except boil faster and quieter. Just doesn't look as cool though.
In reality, expensive kettles are like expensive clothes. They are probably made out of better materials, but the rest is just markup to cover the lower volumes and higher marketing costs. And because people will pay it for a brand name and sleek design.
Retail margins are frequently 50%. (50% margin, 100% markup) Unless a company is vertically integrated. Does the author really not understand that? Markup/margin varies by product and retailer but is still one of the largest factors in the price you pay at retail.
For me the perfect kettle is a simple glass kettle because I've found that it doesn't change the taste of water whereas metal or plastic kettles do. Also, I don't like the idea of heated plastic compounds leaching into my water.
Bonus, it looks cool to see the water start to form bubbles and then to go into a full on boil!
I challenge you to a blind trial. I very much suspect that using an electric kettle and a glass kettle you would not be able to taste the difference of the water once cooled. (We'll run the electric kettle twice with clean water followed by a flush, as most manuals state.
> Also, I don't like the idea of heated plastic compounds leaching into my water.
I don't like the idea to getting burned on my kettle. So if anyone is looking for a kettle that should be metal, invest in one with double walls if you want it for the "look" or one that has palstic outside if you want it for the "taste". Having cheap metal kettle is much worse than having even cheaper plastic one in my opinion.
OK. So given all this thinking, where's the 3D printing era, JIT-manufactured, elegant hack in response that fundamentally rethinks the problem domain and is one with kettle-nature?
I guess the author is saying "kettle is a kettle is a kettle" (except for price, certain design features that don't really count).
One thing they left out of the estimate was the cost of passing national electrical safety regulator test regimes. As anyone who has actually produced new electronics can tell you, this can often be an expensive PITA... particularly for lower-volume products. 100,000 is not high volume.
Please contribute your kettle hack ideas in this thread.
A kettle-element where it used sound to listen for the bubbling of water above instead of measuring heat and automatically dropped temperature. It could track immediate temperature variation (for pots within a certain distance) to attempt to detect waterless operation and perform a shutdown for safety (to prevent fire).
A kettle where it doubles as other things. There are a wide variety of essentially similar cooking appliances (pressure cookers, slow cookers, kettles, Iranian-style rice cookers with crispyness-control, standard or Chinese-style rice cookers, stovetops, etc.) which should be possible to combine more elegantly than the wasteful duplication of the present.
I wouldn't have thought to take apart a simple water boiler (at least not in recent years) so that was enlightening. Sometimes simple but functional designs can be fascinating, after getting to used to doing less with more (arduinos on everything) rather than more with less (completely mechanical control systems).
I have a zojirushi, but only with three temperature settings. Maybe I should mod it to fully variable... although I really want to make a teapot with a built in thermometer more than anything. The water heater wouldn't cool fast enough to really make the variable temp worth it.
>I don’t know how Hamilton Beach did it, and I’m exceedingly curious as to how. The people at Steepster don’t think too highly of it though, so there’s some clues there.
In regards to the $45 variable temperature kettle. The folks at steepster probably didn't care for it because the temperature range is pretty narrow. For high-quality tea, 175-212F simply isn't a wide enough range. It's also not very precise. Many delicate green teas are best prepared at temperatures as low as 140F and in some cases just a few degrees can make a difference.
I bought one recently in the UK - cheapest plastic ones were too flimsy (last couple of kettles died from broken plastic parts [eg in over-complicated lid catches]). Metal ones at the next level up didn't have a level indicator to see how full it is without opening the lid. Next level up from that was about £25-30.
IIRC we paid ~£25 after discount. The best value, of those I found, excluding aesthetics was ~£22 .
An easy way to get temperature controlled water with a standard kettle is to figure out how much cold water you need to add to the bottom of your mug before filling it with (just-boiled) water from the kettle. If you want more accuracy, you can use water from the fridge (which is better at keeping constant temperature than your cold water line).
[+] [-] vacri|12 years ago|reply
This almost made me laugh out loud. Exactly how many kettles does the author think sells each year? Multiply by models and again by manufacturers, and you're talking millions of kettles. Even if you consider that one model will last multiple years, manufacturers don't buy supply batches that last for years. Some industries go in the extreme other direction - the local car industry got its stock-on-shelf lifetime down to 48 minutes from part arriving to part being screwed into car.
Similarly, retail markup is generally 20-50% of the final cost. If you think this is too high (it really isn't) then I suggest you use your new formula to undercut the existing market and disrupt away. Other significant costs are transport and wholesalers (who aren't always the manufacturers). Kettles are bulky items that consume a lot of space in storage and transport. On top of all this, every party involved in the transaction is entitled to make some profit, and not just work for costs. There's also regulatory compliance, things like the CE mark.
Looking at an item and stating that the price shouldn't be more than parts + amortised kickback to the designers is naievity, plain and simple.
[+] [-] thatthatis|12 years ago|reply
That's 10 million total market in the US (100 x .1) and about 16 million in the UK (~20 x .8).
So 26 million total market with a level 1/10th per year or 2.6 million kettles per year. At 100k run per year per manufacturer, the market can then support 26 different models easily.
On the second point, It seemed that he was adding the 2x retail markup into his figures. If you'd followed the link on amazon, you'd see that $90 was market down from about $200.
Sometimes it's best to ask "what would you have to believe for this to be right" before you tear into someone for faulty analysis. All of his number easily pass my smoke tests.
[+] [-] chewxy|12 years ago|reply
As for 100,000 units, yeah, that was probably a mistake. Australia only has 22 million people. No idea why I arbitrarily picked 100,000.
[+] [-] newman314|12 years ago|reply
[+] [-] GuiA|12 years ago|reply
> "The kettle had caused the trip. It was no longer safe to use the kettle"
> You know enough to start designing a temp. controlled kettle, and yet you overlooked the simple (and most likely) possibility that the kettle was on the same circuit with another high draw appliance (hair dryer, electric heater, etc.) and the combination of the two resulted in the trip from overload. And that there was nothing in fact wrong with the kettle at all.
We sometimes forget that our hacker minds can be a weakness :)
[+] [-] tptacek|12 years ago|reply
Is PID control all that expensive? Aren't you talking about a microcontroller, a thermocouple, and a relay?
[+] [-] TheZenPsycho|12 years ago|reply
Quality control in a typical product is really a bigger deal than most hackers think. He didn't account for the fact that if you go to china or hong kong and contract a manufacturing organisation to build your kettle, it's very likely you'll get your first shipment, coming in on your boat or plane and half the kettles are dead or defective or dangerous on arrival. There's nothing to do with those but throw them out, or maybe sell them back over to india for recycling, and the cost of those lost sales is built into the price of the not defective kettles.
The maths here assumes you have no shipping costs and no defective products, no manufacturing problems and no price fluctuations. Doesn't seem very realistic.
[+] [-] chiph|12 years ago|reply
[+] [-] chewxy|12 years ago|reply
[+] [-] timthorn|12 years ago|reply
[+] [-] barrkel|12 years ago|reply
The bimetallic approach can be extended to select temperature. An analogue dial can adjust the switch cutoff position (or alternatively, the starting angle of the bimetallic strip) with a screw. All you'd need to do is calibrate the dial, and the added cost shouldn't be more than 50 US cents on the end retail price.
IMO the reason a "good" kettle costs $90+ is because there isn't enough demand to create enough competition and support enough production to amortize the fixed costs. It's essentially a market broken apart into two of Porter's three fundamental strategies, cost leadership and differentiation. The cheapest kettles would be uncompetitive with a temperature selector even if it added only pennies, while the differentiated kettles have specific features for smaller, less cost sensitive markets. Most people simply don't need temperature selection.
[+] [-] hvidgaard|12 years ago|reply
That said, the adjustable bimetallic solution is certain worth a try, it might just work good enough and be far cheaper and much more reliable in the long run.
[+] [-] bbxiao1|12 years ago|reply
[+] [-] joosters|12 years ago|reply
[1] - https://en.wikipedia.org/wiki/John_Taylor_(inventor)
[2] - https://en.wikipedia.org/wiki/Corpus_Clock
[+] [-] jdlshore|12 years ago|reply
[+] [-] chewxy|12 years ago|reply
[+] [-] shalmanese|12 years ago|reply
In reality, it's likely that either a) these things are being sold at massive profit margins or b) they're being produced very inefficiently with lots of waste in the production process.
[+] [-] lewispollard|12 years ago|reply
That said, I think the kettle thing is mostly a). Companies will price things highly because they've found that people will pay that much, I reckon it's as simple as that.
[+] [-] maho|12 years ago|reply
This is not correct. The boiling point of water is a function of atmospheric pressure [1]. Weather changes the atmospheric pressure by up to 50mbar, which translates to a couple degrees of variation in the boiling point.
The pressure variation due to height is even more severe [2]. At an elevation of 3000m the atmospheric pressure is typically only 700mbar, which means that water boils at 90 degrees.
How does the basic bimetallic strip know the outside pressure and the boiling-point-curve of water so that is knows when to stop the kettle?
I don't think it knows anything about that. Instead I assume once the water starts boiling, the bubbling steam-"padding" around the heating element lowers the heat transfer rate from the heating element to the liquid. This means that the heating element will quickly get a lot hotter until it reaches the threshold temperature of the bimetallic switch.
[1] http://www.engineeringtoolbox.com/boiling-point-water-d_926....
[2] http://en.wikipedia.org/wiki/Atmospheric_pressure
[+] [-] dsuth|12 years ago|reply
[+] [-] asgard1024|12 years ago|reply
I thought there is electronics which simply detects not only absolute temperature, but also change. Once the temperature stops changing and is around 100 degrees, it will stop.
[+] [-] PhasmaFelis|12 years ago|reply
[+] [-] enra|12 years ago|reply
White, green, oolong or really any kind good black tea might require less than boiling temperatures to extract enough out of tea while preserving the taste or other wished effects of the tea. The temperatures, amount and the steep time might be different by each specific tea or batch.
So a kettle with a temperature control can be helpful and save time with tea or cooking if you want finer control than boiling - not boiling.
[+] [-] teaComposition|12 years ago|reply
[+] [-] aestra|12 years ago|reply
Different teas require different water temperatures AND different steeping times for the best taste. Generally the less oxidized the tea the lower the water temperature. I find the worst offense is most Americans over steep their tea which makes it very bitter!
People who use a thermometer are very serious. I just guesstimate.
Also, get some high quality tea, the difference in taste is amazing and its not that expensive, only a few cents a cup.
Also - you can reuse tea leaves.
http://lifehacker.com/5697622/the-hackers-guide-to-tea
[+] [-] staticshock|12 years ago|reply
[+] [-] cs02rm0|12 years ago|reply
[+] [-] jeza|12 years ago|reply
[+] [-] btbuildem|12 years ago|reply
[+] [-] patio11|12 years ago|reply
[+] [-] tim333|12 years ago|reply
[+] [-] brc|12 years ago|reply
In reality, expensive kettles are like expensive clothes. They are probably made out of better materials, but the rest is just markup to cover the lower volumes and higher marketing costs. And because people will pay it for a brand name and sleek design.
[+] [-] chewxy|12 years ago|reply
[+] [-] dima55|12 years ago|reply
[+] [-] aychedee|12 years ago|reply
[+] [-] chewxy|12 years ago|reply
[+] [-] arethuza|12 years ago|reply
http://en.wikipedia.org/wiki/Challenger_2#Crew_and_accommoda...
[+] [-] lingben|12 years ago|reply
Bonus, it looks cool to see the water start to form bubbles and then to go into a full on boil!
[+] [-] Angostura|12 years ago|reply
[+] [-] rplnt|12 years ago|reply
I don't like the idea to getting burned on my kettle. So if anyone is looking for a kettle that should be metal, invest in one with double walls if you want it for the "look" or one that has palstic outside if you want it for the "taste". Having cheap metal kettle is much worse than having even cheaper plastic one in my opinion.
[+] [-] mesozoic|12 years ago|reply
[+] [-] csense|12 years ago|reply
Also, electric kettles aren't really a thing in the US. Almost everybody uses the stovetop kind.
[+] [-] contingencies|12 years ago|reply
I guess the author is saying "kettle is a kettle is a kettle" (except for price, certain design features that don't really count).
One thing they left out of the estimate was the cost of passing national electrical safety regulator test regimes. As anyone who has actually produced new electronics can tell you, this can often be an expensive PITA... particularly for lower-volume products. 100,000 is not high volume.
Please contribute your kettle hack ideas in this thread.
[+] [-] contingencies|12 years ago|reply
A kettle where it doubles as other things. There are a wide variety of essentially similar cooking appliances (pressure cookers, slow cookers, kettles, Iranian-style rice cookers with crispyness-control, standard or Chinese-style rice cookers, stovetops, etc.) which should be possible to combine more elegantly than the wasteful duplication of the present.
[+] [-] epaladin|12 years ago|reply
I have a zojirushi, but only with three temperature settings. Maybe I should mod it to fully variable... although I really want to make a teapot with a built in thermometer more than anything. The water heater wouldn't cool fast enough to really make the variable temp worth it.
[+] [-] phaus|12 years ago|reply
In regards to the $45 variable temperature kettle. The folks at steepster probably didn't care for it because the temperature range is pretty narrow. For high-quality tea, 175-212F simply isn't a wide enough range. It's also not very precise. Many delicate green teas are best prepared at temperatures as low as 140F and in some cases just a few degrees can make a difference.
[+] [-] BgSpnnrs|12 years ago|reply
I guess in the UK they are counted as a necessity and are cheap :P
[+] [-] pbhjpbhj|12 years ago|reply
IIRC we paid ~£25 after discount. The best value, of those I found, excluding aesthetics was ~£22 .
[+] [-] boyter|12 years ago|reply
[+] [-] zurn|12 years ago|reply