4 ms·

It’s also really hard to make things that last at least X long but hardly event more than Y. I know an engineer who spent two years of his life making sure the

by K0balt 2y ago

It’s also really hard to make things that last at least X long but hardly event more than Y. I know an engineer who spent two years of his life making sure the new water pump designs would fail at warranty + 50 percent, but only in an annoying, non catastrophic way. Also, plastics that last very specific amounts of time are common in specific pieces of assemblies in mechanical timers for refrigerator defrosters and the little crossbars that tie the vanes in air vent directors together. Replacement timers use all nylon gears and last “forever”. The one I personally uncovered is a Honeywell thermostat. It is a direct replacement for a mechanical thermostat that would frequently fail about 10-15 years out due to corroded/pitted contacts. The all electronic replacement does not have this problem, but they still failed around 10 years out, but with remarkable predictability in my friends apartment complex. I reverse engineered one. It is powered by the 16-24v signal line. It uses a simple potentiometer to set the temperature, no clock, memory or other features. It has a battery soldered on the circuit board. The battery slowly discharges while the unit is on. In about 10 years of operation, the battery voltage drops below 1v or so. The battery powers nothing, but the microcontroller senses it’s voltage and when it is too low, it changes the behaviour of the thermostat to randomise the temperature cut in/out points by about 10 degrees Fahrenheit , making the thermostat annoyingly unpredictable in a way that is very similar to the typical failure mode of the old thermostat it replaced. One notable difference is that the electronic one will never fail (unless it is in the off position) to come on at 45F or lower, preventing the programmed random behaviour from provoking a freeze-up and damage to structures, so I guess that’s nice?

salviati 2y ago
This is an incredibly useful investigation! Did you publish it somewhere?
- h0l0cube 2y ago
  +1 on this. I don't think I've read a story about how planned obsolescence is achieved in such a novel and non-plausibly deniable way. By that, I mean they haven't just cheaped out on materials, they've spent extra to make it fail predictably.
  - K0balt 2y ago
    I should have written it up. I could still, but I’d need to order one of those thermostats and do the teardown again. At the time I was just focused on why my buddy was having to replace 200 thermostats in ten years. It turned out you could just cut out the battery with a pair of dikes and jumper the leftover positive post to 3v to get basically unlimited lifespan, so he did that instead of replacing the thermostats with new ones. Afaik most are still working fine. Helping him out is also how I figured out the defrost timer disintegrating gears thing. When you do things at scale, things that seem random in onesies practically scream at you. It made me appreciate the value gathering data…you can find the patterns at lower scales. The car air vent thing I figured out on my 94 Toyota 4runner. The air vent crossbars that keep the vanes in alignment with each other all failed over a two year period. A minor annoyance, but it makes you feel like you need a new car lol. I popped them out and found that of all of the plastic parts, only the crossbars were exceptionally brittle. Suspiciously, the bars also had what looked like date codes molded into them. None of the other pieces had numbers at all. I just printed new crossbars.
    - h0l0cube 2y ago
      Oh well. These comments alone are at least a microblog entry. But if you cross something like that again, and have the time and the inclination, I think a HN submission would be super appreciated.
  - itchyouch 2y ago
    I noticed the promise of LED bulbs lasting forever were engineered to fail. I replaced all the bulbs in my house with and about 1-2 years in, many have failed. Though interestingly LEDs in various components or even LED strip lighting seem to last for many many years. Le sigh.
mschuster91 2y ago
> The battery powers nothing, but the microcontroller senses it’s voltage and when it is too low, it changes the behaviour of the thermostat to randomise the temperature cut in/out points by about 10 degrees Fahrenheit , making the thermostat annoyingly unpredictable in a way that is very similar to the typical failure mode of the old thermostat it replaced. This should be criminally investigated and the person who ordered it be put in prison for at least a decade.
- salviati 2y ago
  Why not at least 9? Or 5? I think it would be best to focus on the deterrent effect for the future: we need a law that makes this business strategy not viable. Not on punishing bad behavior that already happened. Maybe such law already exists, but we need more enforcement. Or a better thought out law. I don't think it's important if _that_ person gets jail time. I would not particularly rejoice at the news. But if somehow this practice was made impossible or impractical, I'd
  - wongarsu 2y ago
    One of the reasons for punishment is deterrence. It it becomes clear people consistently go to prison for doing something like this that will reduce the likelihood of people doing this in the future
  - joshuaissac 2y ago
    Or at least make it mandatory to disclose such behaviours before purchase. Failure to disclose should result in the vendor and the manufacturer becoming liable for the repair/replacement costs (with the vendor similarly able to push the costs to the manufacturer if it was not disclosed to them either), as well as any actual damages resulting from the failure of the product.
  - toss1 2y ago
    Need the jail time and a safe harbor if the behavior is fully disclosed in advance with all advertising (a simple phrase will do such as: "Useful life limited to ~10 years, details at xyz") Some people might be fine with a product with a known lifespan, or want to pay more for the unlimited life version The penalty should be more like corporate death than individual prison, as that often gets fobbed off on some scapegoat rather than on the actual manager responsible
mort96 2y ago
> I know an engineer who spent two years of his life making sure the new water pump designs would fail at warranty + 50 percent, but only in an annoying, non catastrophic way. Wow what an abhorrent waste of talent and life.
- albrewer 2y ago
  In mechanical design, you typically target an order of magnitude of stress cycling for product design. In a pump, everything stress cycles, so it all needs to be simulated. If this was a pump you were going to make ten million of, then suddenly every fractional 10th of a cent you save becomes the difference between, e.g., having another coworker or not. So to balance that with offering a reasonable warranty such that there's actually demand for this product makes sense. Before anyone brings it up: sure, a lot of companies just pocket this savings or whatever, but a lot don't; you just don't hear about them because they're typically midsize companies that nobody complains about.
  - mort96 2y ago
    I'm sorry, but I feel like you're reading my message extremely uncharitably. I'm obviously onboard with the idea that nothing lasts forever, and time spent figuring out how to increase something's lifespan to "at least X years" is obviously valuable, as is time spent figuring out how to cut costs without making a product break "before X years". But none of that is the same as spending time to figure out how to ensure that something breaks at the right time. It matters whether the focus is on reducing costs while keeping track of the impact on the product's lifetime, or the focus is on reducing the product's lifetime. What I'm calling a waste of talent and human life is spending time on the latter, and that's what it sounds like my parent comment describes their engineer friend doing.
    - eschaton 2y ago
      Amen, intent matters. And it sounds like in both of the cases the OP cited, the intent was to force otherwise-unnecessary replacement, which is bad.
    - 2y ago
matthewfcarlson 2y ago
While I don’t doubt the behavior, I have a hard time believing that a product manager would let an expensive part like a battery get added to the BOM if it’s only purpose was to fail after ten years. Which suggests it performs some sort of function, which means this could be a bug rather than a malicious act. We will likely never know but I’m always willing to assign stupidity rather than malice
- hulitu 2y ago
  > While I don’t doubt the behavior, I have a hard time believing that a product manager would let an expensive part like a battery get added to the BOM if it’s only purpose was to fail after ten years. It depends how much of the BOM price was the battery.
- K0balt 2y ago
  When the battery is removed and the pin pulled up to the 3v bus, the thermostat works flawlessly. I traced the circuit, it goes between ground and the uC pin, through a 1 Mohm resistor, no other connection. It’s about right for killing a 300mah battery over 10 years. The pin is held low when the unit is energized by the thermostat signal lines.
jefftk 2y ago
> The battery powers nothing, but the microcontroller senses it’s voltage and when it is too low, it changes the behaviour of the thermostat to randomise the temperature cut in/out points by about 10 degrees Fahrenheit This is really neat, if true, but I have to say I'm skeptical. This is just too good a story!
- K0balt 2y ago
  Pick one up and see for yourself. I think they still make them. It’s the basic round dial type thermostat from Honeywell. It uses an at328p MCU and it even has a programming header. The debug was open on the ones I played with, so I downloaded the code, but I never got around to (or had the tools to) disassemble it. I was going to just write an arduino sketch to replace the factory code, but we figured out the “cut out the battery and jumper to 3v “ solution so I never did. Saved about $4000 in thermostats replacements though.
andruby 2y ago
> It has a battery soldered on the circuit board. The battery slowly discharges while the unit is on. In about 10 years of operation, the battery voltage drops below 1v or so. The battery powers nothing I am not an electrical engineer. Could the microcontroller use the battery as some kind of calibration? Or could it have another function?
eschaton 2y ago
So you know of two cases of companies putting in work to defraud people by selling products that aren’t fit for purpose outside their warranty window. Name & shame.

by K0balt 2y ago

salviati 2y ago

This is an incredibly useful investigation! Did you publish it somewhere?

h0l0cube 2y ago
+1 on this. I don't think I've read a story about how planned obsolescence is achieved in such a novel and non-plausibly deniable way. By that, I mean they haven't just cheaped out on materials, they've spent extra to make it fail predictably.
- K0balt 2y ago
  I should have written it up. I could still, but I’d need to order one of those thermostats and do the teardown again. At the time I was just focused on why my buddy was having to replace 200 thermostats in ten years. It turned out you could just cut out the battery with a pair of dikes and jumper the leftover positive post to 3v to get basically unlimited lifespan, so he did that instead of replacing the thermostats with new ones. Afaik most are still working fine. Helping him out is also how I figured out the defrost timer disintegrating gears thing. When you do things at scale, things that seem random in onesies practically scream at you. It made me appreciate the value gathering data…you can find the patterns at lower scales. The car air vent thing I figured out on my 94 Toyota 4runner. The air vent crossbars that keep the vanes in alignment with each other all failed over a two year period. A minor annoyance, but it makes you feel like you need a new car lol. I popped them out and found that of all of the plastic parts, only the crossbars were exceptionally brittle. Suspiciously, the bars also had what looked like date codes molded into them. None of the other pieces had numbers at all. I just printed new crossbars.
  - h0l0cube 2y ago
    Oh well. These comments alone are at least a microblog entry. But if you cross something like that again, and have the time and the inclination, I think a HN submission would be super appreciated.
- itchyouch 2y ago
  I noticed the promise of LED bulbs lasting forever were engineered to fail. I replaced all the bulbs in my house with and about 1-2 years in, many have failed. Though interestingly LEDs in various components or even LED strip lighting seem to last for many many years. Le sigh.

mschuster91 2y ago

> The battery powers nothing, but the microcontroller senses it’s voltage and when it is too low, it changes the behaviour of the thermostat to randomise the temperature cut in/out points by about 10 degrees Fahrenheit , making the thermostat annoyingly unpredictable in a way that is very similar to the typical failure mode of the old thermostat it replaced. This should be criminally investigated and the person who ordered it be put in prison for at least a decade.

salviati 2y ago
Why not at least 9? Or 5? I think it would be best to focus on the deterrent effect for the future: we need a law that makes this business strategy not viable. Not on punishing bad behavior that already happened. Maybe such law already exists, but we need more enforcement. Or a better thought out law. I don't think it's important if _that_ person gets jail time. I would not particularly rejoice at the news. But if somehow this practice was made impossible or impractical, I'd
- wongarsu 2y ago
  One of the reasons for punishment is deterrence. It it becomes clear people consistently go to prison for doing something like this that will reduce the likelihood of people doing this in the future
- joshuaissac 2y ago
  Or at least make it mandatory to disclose such behaviours before purchase. Failure to disclose should result in the vendor and the manufacturer becoming liable for the repair/replacement costs (with the vendor similarly able to push the costs to the manufacturer if it was not disclosed to them either), as well as any actual damages resulting from the failure of the product.
- toss1 2y ago
  Need the jail time and a safe harbor if the behavior is fully disclosed in advance with all advertising (a simple phrase will do such as: "Useful life limited to ~10 years, details at xyz") Some people might be fine with a product with a known lifespan, or want to pay more for the unlimited life version The penalty should be more like corporate death than individual prison, as that often gets fobbed off on some scapegoat rather than on the actual manager responsible

mort96 2y ago

> I know an engineer who spent two years of his life making sure the new water pump designs would fail at warranty + 50 percent, but only in an annoying, non catastrophic way. Wow what an abhorrent waste of talent and life.

albrewer 2y ago
In mechanical design, you typically target an order of magnitude of stress cycling for product design. In a pump, everything stress cycles, so it all needs to be simulated. If this was a pump you were going to make ten million of, then suddenly every fractional 10th of a cent you save becomes the difference between, e.g., having another coworker or not. So to balance that with offering a reasonable warranty such that there's actually demand for this product makes sense. Before anyone brings it up: sure, a lot of companies just pocket this savings or whatever, but a lot don't; you just don't hear about them because they're typically midsize companies that nobody complains about.
- mort96 2y ago
  I'm sorry, but I feel like you're reading my message extremely uncharitably. I'm obviously onboard with the idea that nothing lasts forever, and time spent figuring out how to increase something's lifespan to "at least X years" is obviously valuable, as is time spent figuring out how to cut costs without making a product break "before X years". But none of that is the same as spending time to figure out how to ensure that something breaks at the right time. It matters whether the focus is on reducing costs while keeping track of the impact on the product's lifetime, or the focus is on reducing the product's lifetime. What I'm calling a waste of talent and human life is spending time on the latter, and that's what it sounds like my parent comment describes their engineer friend doing.
  - eschaton 2y ago
    Amen, intent matters. And it sounds like in both of the cases the OP cited, the intent was to force otherwise-unnecessary replacement, which is bad.
  - 2y ago

matthewfcarlson 2y ago

While I don’t doubt the behavior, I have a hard time believing that a product manager would let an expensive part like a battery get added to the BOM if it’s only purpose was to fail after ten years. Which suggests it performs some sort of function, which means this could be a bug rather than a malicious act. We will likely never know but I’m always willing to assign stupidity rather than malice

hulitu 2y ago
> While I don’t doubt the behavior, I have a hard time believing that a product manager would let an expensive part like a battery get added to the BOM if it’s only purpose was to fail after ten years. It depends how much of the BOM price was the battery.
K0balt 2y ago
When the battery is removed and the pin pulled up to the 3v bus, the thermostat works flawlessly. I traced the circuit, it goes between ground and the uC pin, through a 1 Mohm resistor, no other connection. It’s about right for killing a 300mah battery over 10 years. The pin is held low when the unit is energized by the thermostat signal lines.

jefftk 2y ago

K0balt 2y ago
Pick one up and see for yourself. I think they still make them. It’s the basic round dial type thermostat from Honeywell. It uses an at328p MCU and it even has a programming header. The debug was open on the ones I played with, so I downloaded the code, but I never got around to (or had the tools to) disassemble it. I was going to just write an arduino sketch to replace the factory code, but we figured out the “cut out the battery and jumper to 3v “ solution so I never did. Saved about $4000 in thermostats replacements though.

andruby 2y ago

> It has a battery soldered on the circuit board. The battery slowly discharges while the unit is on. In about 10 years of operation, the battery voltage drops below 1v or so. The battery powers nothing I am not an electrical engineer. Could the microcontroller use the battery as some kind of calibration? Or could it have another function?

eschaton 2y ago

So you know of two cases of companies putting in work to defraud people by selling products that aren’t fit for purpose outside their warranty window. Name & shame.