Why do many appliances, even ones that aren't cheap, have such poor duty cycles? 4

[LMF5000]

I figured this is probably the correct subforum since it relates to electrical motors.

I noticed that paper shredders and stand mixers, to name a few, have abysmally low duty cycles. Every one of the 50-dollar shredders in the office will overheat and enter protective shutdown after 5 minutes of non-stop running, and need a 20-minute cooldown. Was it really cheaper to integrate the temperature sensor, overheat light, and resettable shutoff switch than fitting a bigger fan to the motor and molding an external exhaust port in the housing? All these different shredder models lack any air exhaust outside.

I'm aware that continuous-duty shredders exist, but the cost jumps up massively for them, by a factor of 2x to 4x. Is it that hard to make a cheap, continuous-duty shredder? Ours draw 300W from the wall socket. A 20-dollar electric corded drill with a 500W motor can run for at least 30 minutes without overheating while drawing 200-300W (I had the misfortune of testing it myself trying to drill porcelain tile with a cheap worn out bit), so it seems the technology to manufacture a motor of the required size and power level cheaply exists - is there something I'm missing?

Secondly, stand mixers. Our 1980s Kenwood stand mixer (from the Thorn EMI vintage) would run nonstop for up to an hour at a time making batch after batch of cake batter or frosting for parties (ultimately it died when the capacitors exploded after approximately 20 years of service). I'm looking at modern stand mixers and every single one says not to exceed 10 minutes of running and allow 20 minutes of cooling afterwards. Not just the 150-dollar budget models, but even the 500-to-700-dollar KitchenAid models. What happened? Is it that hard for a 500-dollar appliance to be able to run continuously at rated power? Have they sacrificed cooling for a sleek exterior devoid of air intake and exhaust ports, or is there something else I'm missing?

 

[wayne440]

Both items are probably built to a market price point and have the cost of various production options calculated down to fractions of a cent. Many of the reasons may be similar to those that have prevented a lunchbox sized, turbocharged, 5kw portable generator from appearing on the market.

 

[waross]

When you compare the market for light duty machines to the market for continuous duty machines, or to put it another way, the number of buyers satisfied with a light duty machine compared to the number of buyers needing and willing to pay for a continuous duty machine, The loss of economies of volume become apparent.
Engineering and design costs, startup costs, and other fixed costs will be spread over a lesser number of machines.
The smaller numbers of machines tends to drive per unit costs of components up.
\Sadly, few people are willing to pay extra for quality, which often tends to drive the price of quality up disproportionately.

Bill
--------------------
Ohm's law
Not just a good idea;
It's the LAW!

 

[LMF5000]

Many of the reasons may be similar to those that have prevented a lunchbox sized, turbocharged, 5kw portable generator from appearing on the market.

I see you remember my earlier post .

Care to substantiate your theory? Sorry, but I can't see how buyers of premium branded stand mixers are going to be put off by a fraction of a cent in added cost to drastically improve the duty cycle of their very expensive machines. You don't buy a premium brand if you're after pinching pennies. The reviews absolutely lambasted them about this and lamented how they don't make things like they used to, so it would appear I'm not that much out of tune with the wants of regular consumers.

Heck, I could buy a Chinese machine for half the price, incorporate a brushless DC fan driven by one of those temperature-sensing fan drivers you can buy for on Aliexpress, 3D-print a new housing incorporating all of the above, and still come out cheaper than a premium stand mixer. So, explain to me, really, why the manufacturer didn't do that? Have we become a society where the name and reputation is worth more than the actual superior engineering that gave them that reputation to begin with?

Granted, the marketing material of everything for sale nowadays says practically the same thing about every machine in their lineup and goes through great lengths to obfuscate or entirely eliminate any talk about the technical differences (for example, try figuring out the difference between Optima redtop, bluetop and yellowtop batteries). It takes a lot of effort to cut through the male cow excrement and get to what is really different between machines of different price points (like metal gears vs. plastic gears). Maybe that has something to do with it.

 

[cranky108]

Removing heat as you should know requires some mass of cooling fins, which likely cost more than a penny. Plus larger copper wire in the motor.
This would also increase the size of the appliance.

All the same, most cars could work with a 25 HP engine, but most customers expect more than 5 times that.
The same for appliances, most people expect a lot of power, for a short time.

Blame the market for sizing around what most customers want.

 

[LMF5000]

Thanks Bill.

Sadly, few people are willing to pay extra for quality, which often tends to drive the price of quality up disproportionately.

Part of the problem is that quality has become hard to perceive due to the way things are marketed. As an exercise, try and explain to me the difference between Optima's Bluetop, Yellowtop and Redtop lines of batteries. Each are optimised for a particular application (which I suspect is starting, hybrid, deep cycle), but the website says the same good things about each of them and doesn't go into the technical differences at all. There is literally zero information available to the buyer to justify why one lineup costs 2x the price of the other (I happen to know that deep cycle use significantly more lead, but this information is hidden from the buyer).

Another example - I was looking for a toaster. One of the simplest appliances known to man. In the descriptions they wax lyrical about how awesome this toaster is and basically describe to the reader what a toaster does. They were praising the automatic pop-up feature like it hasn't been standard on every toaster ever made for decades. One particular manufacturer had two 2-slot for-slice toasters in their lineup, both stainless steel, both the same size, both with three buttons and a knob and the same features. But one cost $40, the other $60. With no idea what made them different I turned to the reviews on Amazon. The $40 one was a rebadged Chinese model that many users complained toasted unevenly. The $60 one was praised by reviewers for toasting very evenly. So it seems in this case more cash buys better quality.

I don't mind paying extra for quality, and most people I know don't mind either, but they have to know what they're paying for. Something I hear very often is "I just bought the cheapest one, they're all the same anyway!" I wish sales and marketing would be straight with consumers and tell us exactly why they're charging the price that they do, and provide justifications for charging more. Or maybe they found that treating consumers like they're dummies and pretending their cheapest product will work as well as their most expensive one is more profitable for them than showing in the specs sheets exactly what they improved for the money.

 

[cranky108]

sadly, the world is not designed for the needs of engineers.

 

[itsmoked]

I think you're having bad luck or buying the cheapest crap. I went to Office Max and bought a cross-shredder. I've fed paper into it for hours at a time until MY duty cycle was up. We've probably run... ~2M pages thru it without it ever stopping on overheat. We keep below what we estimate to being 12 pages at a time. We don't ever let it shut off between pages.

My kitchen stand mixer, I've left it going on a large batch of chocolate chip cookies while a phone call went out past 30 minutes. No issues. That said, I wouldn't leave it churning a triple batch of coffee cake batter for a moment longer than I thought it needed to mix the ingredients.

Keith Cress
kcress -

http://www.flaminsystems.com

 

[LMF5000]

Re shredders, we have a few types in the office (Rexel branded) and I've reliably gotten them to overheat when processing a backlog of papers. I used a stopwatch at the time, it was under 10 minutes from start to when the overheat light lit up and the shredder wouldn't work until it cooled down.

Re stand mixers, I'm sure in real life they can make it past 10 minutes, but the instruction book specifically has 10 minutes written down (and as I said multiple times, this is not cheap crap, this is high-end crap), and the warranty will not cover damage caused by running for longer than the listed times.

I was looking for some good-quality insight into why things are the way they are. But most of the replies just fob off my questions by ascribing blame to "higher costs" - yet nobody has substantiated it with an inkling of how much it would cost, nor an idea of the bill of materials for a typical stand mixer so we can look at what they actually spend their money on.

Heck, maybe the real reason isn't engineering, maybe it's because by putting that 10-minute line in there they have a convenient way to deny all warranty claims by blaming the user for running it too long. Maybe it's just CYA designed with the stupidest of their users in mind, who would try to knead a heavy dough using the wrong attachment at full speed for many minutes longer than anyone in his right mind would do, under which conditions even the best mixer might start smoking in under 10 minutes. Or maybe all stand mixers are made in the same factory in China so they all get that line copy-pasted. I don't know, do any of you have any experience in this particular area?

 

[IRstuff]

because by putting that 10-minute line in there they have a convenient way to deny all warranty claims by blaming the user for running it too long.

THAT is a cost factor; Anything longer than that, they'd have to test to destruction, which is also a cost factor. That's why food expiration dates are also short; they don't have to deal with actual spoilage returns because their expiration dates are well below the point of actual expiration. The Japanese demonstrated in the 1970s and 1980s that it didn't cost much, manufacturing-wise to extend mechanical lifetime by double or triple, BUT you have to spend the money to understand and characterize your manufacturing process and components well enough to figure out HOW to design it to last forever. But, then again, why would you EVER want to design something where the customer NEVER buys another one from you again? That's economic suicide.

TTFN (ta ta for now)
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[dik]

This will likely change in the not too distant future... where longevity will have to be built in.

Rather than think climate change and the corona virus as science, think of it as the wrath of God. Feel any better?

-Dik

 

[stevenal]

Perhaps the duty cycle could be disclosed up front so a consumer could make an informed choice. I find it's buried deep in the manual if it's disclosed at all.

 

[cranky108]

Food not expiring? Twenkies will last forever.

Do you actually believe the warranty is anything except an empty bag of $$$$?
Then let me sell you an extended warranty.

Yes I have a stand mixer that will operate for longer then 10 minutes. I even changed the grease in the gear box with my daughter a few years ago.

This should also be where the right to repair should come in.

 

[LMF5000]

With things like appliances, the right to repair isn't really a problem - the main problem is finding parts, and whether they are cheap enough to make the repair viable. Let me tell you a story. Our old 1981 Kenwood A901DL stand mixer (with a centrifugal governor for controlling motor speed) ran fine for a little over 20 years, until the capacitors blew up one day mid-whisking. A new board was only $30 on eBay, but I didn't know it at the time, so the mixer was sadly disposed of after a few years taking up space because we couldn't find parts locally. Its replacement was a Kenwood chef titanium, costing an eye-watering amount of money in the early 2010s (something like €700 in today's money). Eventually its speed controller died (it would run at full throttle regardless of dial position), and was replaced by myself for €60 in parts. So far the Kenwood is still running.

This month, it was time to buy a new mixer for myself. I looked at the options, and opted for a middle-of-the-road model from a Chinese brand (a Royalty Line RL-PKM1900.7BG) costing €245. My reasoning was that since parts are expensive and all the good (expensive) mixers we've had ended up breaking and needing repairs anyway, I might as well buy the cheapest one I can live with, use it until it dies, then just buy another one. It's not a great strategy from a sustainability standpoint (though the parts are recyclable), but with this strategy, I can buy three completely brand new cheap mixers for the cost of one supposedly good-quality mixer. The only downside is less "quality" (which translates to things being made of plastic instead of metal), but this is offset by the mixer being new (and hence starting a new warranty) each time it's replaced.

The reason the warranty matters is, firstly, it is the only solid indication of how long the manufacturer has intended it to last. All the marketing BS will proclaim how "strong" and "durable" the product is, but if this mixer has a 2-year warranty and that one has a 5-year warranty, you can bet the latter is very likely going to last longer under the same conditions. Secondly, and more importantly, parts are hard to get (and getting increasingly harder due to the pandemic effects) and sometimes expensive, so during warranty if it breaks you get a new, working machine at the shop's expense. Once the warranty is out, you either use your engineering skills to make it work, or you're out of luck.

Which brings me back to my original question. Mixers of old never stipulated a running time limit. How is it that nowadays they do? Have we decided to regress in this area?

 

[cranky108]

Years ago I bought a kitchen aid mixer, and the only problems I have had with it was to replace the grease in the gearbox after years of operation/ sitting. It was sitting because it is big, and did not fit on the counter of our old house. It still works, and you are correct it has metal gears, and does not lack power like cheaper mixers.
Downside is the cost.
Same kind of thing with vacuums.

On the other hand, I would not purchase anything but the lowest cost dryer my wife will accept. They are not very complicated, except the sheet metal skin, which I can't bend myself.
And the parts are easy to find.

So buy quality for something that should last. But if parts are available, buy to the equipment you can repair.
The right to repair, including making parts available, is important.

 

[danw2]

Is the warranty worth anything?

Not to me. Our LG refrigerator's compressor died about 90 days before the 5 year compressor warranty expired.

The local appliance repair place (an LG authorized repair place) explained that the LG warranty covers parts only, it does not cover labor, which would have been $600 with the caveat that only after the compressor is replaced can they test the 'brain board' to see if it is still functional. The controller card replacement was a potential $200 additional. Compressor parts would take 2 weeks for delivery, all the while the household has no operating refrigerator. Repair place also mentioned that we were the 15th call on LG fridges in the past two weeks. Must have been a bad lot of something or other. We bought a new fridge and junked the LG.

The appliance repair place was quite frank about performance quality: "LG and Samsung make nice electronic equipment but are still cutting their teeth on appliances." They recommended US manufacturers for appliances.

 

[dik]

Bad design... it should have been 90 days 'after'...

Rather than think climate change and the corona virus as science, think of it as the wrath of God. Feel any better?

-Dik

 

[cranky108]

Did you send in the warranty card?

That said, I had a maytag washer for years, and when it quit time before last, I called someone to look at it. I was in luck because the warranty would pay for a new transmission, and the labor was not very much.
The last time it fail, it was the same issue, but the warranty had run out.
The only think about the new maytag appliances is the nametags on the front of the things. If it looks bad on my dryer, it looks worse on my range.

Yes I know maytag is not exactly known for ranges, but when the kenmore cooktop could not be replaced, because of parts, and sears is no longer in the area, the maytag looked like a good deal.

 

[danw2]

>Did you send in the warranty card?"

I don't recall, but it wasn't necessary - I had the receipt and all the documentation.

The manufacturer's interpretation of "5 year coverage on the compressor" meant parts replacement only, not including labor. Labor costs were a significant fraction of the cost of a replacement fridge.

Good Luck with Maytag. My brother-in-law cried when his 45 year old Maytag finally died, transmission failure. He and I bought Maytag washers with a couple months of each other back in the late 1970's. Maytag went the make-'em-cheapo route in the early 2000's and then Whirlpool bought them making them even cheaper yet. I foolishly bought a Maytag one in the early 2000's and it died within 6-7 years, transmission failure. I went with Speed Queen for its traditional design, an electromechanical timer, no microprocessor.

 

[LMF5000]

I'm based in Europe. The law here is that all products must carry a minimum 2-year warranty for parts AND labour. It makes it slightly more likely for the vendor to just give you a new unit when the parts and labour to fix it are some 70% of the value of a new appliance.

The phenomenon of manufacturers selling out is not new, it's happening to everything. Bosch for example used to mean expensive and good. Nowadays they're made in China alongside other power tools, and they cost practically the same as other brands with a much shorter history and much less of a reputation.

The best strategy appears to be to buy the cheapest product that has the features and performance that you need. Let's say I wanted a tumble dryer. Since energy is expensive here, I would buy the cheapest heat-pump dryer in the shops (no traditional resistive-element or condenser dryers for me; our old resistive used 1200W during drying, our new heat-pump uses just 400W). I would not pay extra to go for a dryer made by a manufacturer with a better name/reputation - because as all of you have pointed out, that "name" for quality was likely earned earlier in the century and nowadays they just use the same generic components as everyone else. If you're not getting something you can feel, touch or measure (more features, more energy efficiency or performance in whatever the figure-of-merit is for that appliance, better materials to the touch, or longer warranty), then you're just paying more for nothing.

Given the choice of a €500 dryer and a €1000 one, you're probably better off with the €500 one. Once it breaks you throw it away and buy another one, and unless the €1000 one would have lasted twice as long (doubtful), you've made a net gain. It's far easier to buy a new one than do heavy fixes to an older one.