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Plastic gears that break can be intentional, good design for better repairability.

If a mechanism jams, something has to give. This may be the motor, which may survive being jammed indefinitely, or it could burn up, causing a more expensive problem. In a mixer, the motor is probably decently powerful and doesn't tolerate being jammed.

If there's enough gear reduction, then a jam can develop enough force to bend shafts or break mountings and other components. That can make the product impossible to repair, if some injection molded bit that was supposed to hold stuff in place was broken.

A well placed plastic gear that breaks and saves the rest of the mechanism can make repair far easier and cheaper. And gears are very standard components that are far easier to find replacements for than some weird injection molded thing being made for one specific model of mixer.

Great example of why "planned obsolescence" isn't always bad. In this case the weak gear acts alike a kind of mechanical fuse. So long as it's within a context of easy replacement.

But then it isn’t planned obsolescence. It is planned obsolescence if the plastic gear wears and breaks down without a jam occurring. In your model it is a fail safe or circuit breaker. In the GP it a part designed to fail sooner (in wall clock time) to make sure you buy a new product.

But that's the crux of engineering: these two things are in tension – the part which is designed to fail safely if a jam occurs will, by its very nature, also be subject to wearing down sooner than if it were made of cast iron and caused the entire mixer to fail catastrophically during a jam.

In reality, nothing is so simple as waving your hands and declaring "no plastic 'planned obsolescence' parts!". Everything is a trade-off. A more effective way of pushing companies to position the trade-off in a way that rewards long-term durability would probably be to mandate longer warranty periods, rather than try to dictate what gears ought to be made out of in a vacuum divorced from the tradeoffs involved.

There are overload protection mechanisms without sacrificial parts, e.g. ball detents. They don't inherently have to wear down faster. Plastic gears are likely cheaper and lighter, though.

The key would seem to be if the part that fails is easily replaceable, then. If I make a design that has a part meant to fail-safe in a situation that would otherwise be dangerous to the other devices (I'm an EE rather than an ME, so we'll call it a "fuse"), the good-faith repairability practice is to put the part in an accessible location and make it a part that is readily available. If I wanted to encourage replacement of the whole device, maybe I make it a soldered-on part in the potted section of the PCB.

I was quite pleased with the design for the current measurement fuse on my HP 3458A meter: https://youtu.be/sdyDUl5xYpE

But taken to an extreme each car would look like a military truck (because each component could have been made stronger) - to prove planned obsolescence you'd have to show that the rest of the device will last longer than the part and there's a comparable part that would work better.

For example timing chains vs timing belts, apparently there are reasons they choose one over the other, but maintenance is part of keeping them operational.

>Plastic gears that break can be intentional, good design for better repairability.

If it was a planned safety features then spare gears could be included or easy to find and buy for cheap(a device I bought had a safety fuse and it comed with 3 extra ones , also it was designed to be simple to replace it, no screws or "genius" needed. On the other hand a laptop of mine got destroyed by a high power voltage, but not destroyed at once, made me spent some more money on repairs until it finally died, all because some cheap safety feature was not included (even if hard to replace))

There are other (better) but more expensive ways to prevent damage to the motor. The plastic gear in a mixer is the cheapest way to solve the problem while also ensuring the device wears out fairly quick compared to a better built unit. It’s a win win for the manufacture while a total loss for the consumer (and environment)

Here's a comment I posted a year ago about the sacrificial plastic gear in a Baratza coffee grinder:

https://news.ycombinator.com/item?id=27018629

One of the replies is a truly frightening story about people who broke the sacrificial gear in the tailgate window mechanism of their Toyota Landcruiser and machined a new one out of brass!

Frictions are not a new thing: for a simple mixer you just need a friction coupling with two sandpaper-like washers, Not only it's safer than a braking gear who can spill debris around blocking something else, but it demand essentially no repair...

On our blender, which has a fairly powerful motor, that’s the exact design. There’s a plastic drive coupling that does eventually wear our, but serves primarily as a one-way shear coupling if the blender gets jammed with ice or whatever mechanical stresses a blender is bound to experience.

A 5 pack of the replacement parts plus the tool to hold the shaft still while installing costs $10+tax delivered from Amazon (ASIN B07Y7S33RF).

The trick is, someone has to think to and then want to repair it. When that coupler first wore out, many would assume “oh, the mixer wore out; we have to buy a new one” rather than “a replaceable part wore out; we have to buy and install a new one”.

A few weeks ago, a friend came over with a cracked phone screen and mentioned they were going to buy a new phone the next day. “Why not replace the screen? I did mine last month.” “You can do that?!”

People are in a default buy-again mindset.

The cheap way to do this (and imo better because much better definition of the breaking strain) is a shear pin.

Some ambitious targets there, but I support your general attitude.

> sell a mixer with a plastic gear, easy to speculate that will break after few year, ok, you are allowed to do so, but you get a progressive tax

A poor quality tax, like a sugar tax, seems interesting. Don't sell crap. Measurement and enforcement isn't so easy. Quality of design isn't trivial to assess. Maybe simple MTBF of finished product. Punish excessive returns.

> Another fraud is "spare parts available ONLY to 'certified technicians'"

I see that in the US outfits like Tesla and John Deere hide behind "safety" as a shield. "Right to repair" needs to kerb-stomp that whole conceit. Prove that only a highly skilled technician could possibly perform the repair and that otherwise the consequences are extremely likely to be lethal.

> must be made of standard parts

Mechanical interoperability and "class" part tolerances aren't so unreasonable. The entire electronics industry is built on standard component pitches and package layouts with equivalent component classes published in most cases. Take the 741 op-amp package and you'll find hundreds of pin-compatible devices in any catalogue. We totally can do that for electro-mechanical assemblies.

> all spare parts on sale from the company website, at a reasonable price

No. I don't like the idea of compelled sales. I don't like compelled anything. How about a law that says if you refuse to manufacture and sell parts at a reasonable price you simply lose your patent/trademark and cannot stop any other business making the part for which there is demand?

> ALL software MUST BE open sourced

Gets my vote! :)

> anyone who can prove planned obsolescence

Not sure. Planned obsolescence isn't always a bad thing. It can be a good design trade-off. Comes back to the quality expectations thing. But remote kill switches and "updates of death" should be punished mercilessly.

How do you know MTBF for recent (new) products? If they get a waiver, why wouldn't manufacturers make every product model-year-specific to avoid such a requirement?

If it is anything like hard drives, then you just make up a big number that no one ever actually sees in the real world.

As far as enforcement, one could create a disposal tax chargeable to manufacturers. High quality items should need to be disposed of less frequently.

This kind of tax already exists for recycling programs, so it has to be at least somewhat possible.

> Measurement and enforcement isn't so easy

True, that's why we need such extreme and exaggerate sanction that the other side know it's a large net fishing so most fishes pass through but only one caught is so expensive to being not worth the risk. That's the most classic strategies we have seen few times in the past, and back than it works...

> I see that in the US

It happen also in EU, for instance in France it's mandatory to provide washing machines spare parts for 5-7 years (I do not remember exactly the terms) BUT such parts are only sold to "certified repair centers" witch are generic repair shops who have paid "specific training" on yearly basis and so are "eligible as certified repair shop for $YouNameItBrand", they do not even use much excuses, the laws allow them to restrict part supply...

> No. I don't like the idea of compelled sales

Consider a thing: spare parts in many cases are not profitable to be sold directly to customers. For instance a pump manufacturer for dishwashers might have some private agreement with some top brands that they buy it's pumps only if they are not on sale abroad. If you mandate "sell disassembled and assembled anything" any OEM are trapped: they can't made cartels, because parts prices must sum up not too much more than the complete device with the sole exception of reasonable packaging/shipping fees. If you leave a formally open market for some parts you'll have it, for others no.

> Not sure. Planned obsolescence isn't always a bad thing.

It's not IF you can recycle, like there is no issue in planning a car for just two years of good quality service if the used car can be disassembled and recycled, otherwise the trade off between the initial lower costs and the obsolescence to push innovation vanish in waste as we see today... It's not wrong saying "since thing improve more or less regularly it's a good thing pushing new one even if they are only a bit better, not enough to convince most customers to made the switch, but it's good only if you have solved the circularity of the supply chain issue IMVHO.

Like some here say: "the plastic gear is a sacrificial part" a cheap one, perhaps easy to replace, who happen to avoid bigger damage, sure it can be. But hey we know better safety. For instance in my country we have dropped cheap fuses for AC home electricity for far more expensive thermal and differential switches just because they last decades and you can re-switch them as you wish while fuses might last equally ONLY if no overpower/short happen. Such switches can be recycled not fully but "a bit". The game is the same. If my mixer can last 10+ years, I can change blades as needed, there is no need for sacrificial parts, it's better produce far less, having them more expensive and keep them for a decade. In 10 years they have not improved much, there is no benefit in a quicker market since there is no circularity.

> anything "commodity like" must be made of standard parts for anything critical to it's functionality, that means a washing machine must have a water pump with flexible connection and standard threads / diameters and fixing that you do not need an original one but any "common pump" can be found, whiskers with standard whips inserts etc;

This is a huge one for things that aren't phones and laptops - parts should be as "loosely" coupled as they can be, so that similar but not identical parts can be used. This may involve slightly more complicated designs (think: wash machine that has a pump AND a flow valve or switches in the drum to measure how full it is vs just "run this pump for X minutes and it will be full) but allows for much more durability/long lasting.

However, an additional thing should be done to encourage these repairs - make it so that out-of-warranty repairs/repaired items sold are VAT-free. Once the financial incentives are lined up, people will be begging for dead items they can fix and resell.

> make it so that out-of-warranty repairs/repaired items sold are VAT-free

Customer goes to appliance store. Breaks a $5 part. Store repairs it, and now the customer gets to buy the appliance without VAT plus $5 for the repair?

If the goal is to reduce people’s consumption and incentivize them reuse, then simply increase taxes on newly manufactured goods. It will also incentivize people to buy more repairable goods, and hence incentivize manufacturers to make and sell them.

The idea would be for out of warranty repaired items; in other words, the device was bought years ago and is otherwise destined for the landfill.

Oh, I see. Still seems like more labor required to verify and audit warranty status. Seems simpler to enforce an excise tax on the manufacturer/importer.

> But the real key is the fight against crap: you sell a mixer with a plastic gear, easy to speculate that will break after few year, ok, you are allowed to do so, but you get a progressive tax: as much as durable and repairable is your device you pay less. For a mixer that means: 30% of the sale price as tax if it's expected lifetime is less than 10 years of normal usage.

So the cheaper mixer is now as expensive as the better built one. This means there's no more cheap mixer on the market. How is getting a single mother of three to pay 30% extra taxes to fund some civil servant's pension fund helping anyone?

> Another fraud is "spare parts available ONLY to 'certified technicians'" witch means repair is as expensive a get a new gear.

Thanks to the internet, this problem tends to solve itself. The factory in China will generally happily sell you some.

> anyone who can prove planned obsolescence, like technicians from inside the OEM, get rewarded SIGNIFICANTLY for their publication and the OEM so badly sanctioned that the whistleblower get no issue if is cut off some market, the company loose so much that no one want even try.

The problem is what's the bar for proving it? Every design has a component that will wear out first.

> > But the real key is the fight against crap: you sell a mixer with a plastic gear, easy to speculate that will break after few year, ok, you are allowed to do so, but you get a progressive tax: as much as durable and repairable is your device you pay less. For a mixer that means: 30% of the sale price as tax if it's expected lifetime is less than 10 years of normal usage.

> So the cheaper mixer is now as expensive as the better built one. This means there's no more cheap mixer on the market. How is getting a single mother of three to pay 30% extra taxes to fund some civil servant's pension fund helping anyone?

Is it better to have an invisible "poor tax" that makes your single mother spend 2-3x the price of the cheap one over 10 years since it breaks so much faster instead of having to save up longer initially for the one that probably won't break in ten years?

Could do an escrow/deposit style thing so you can get your money back if your cheap shit actually doesn't break faster. So there's an incentive to make things cheaper only if you are confident in your long-term business model and reliability.

> Is it better to have an invisible "poor tax" that makes your single mother spend 2-3x the price of the cheap one over 10 years since it breaks so much faster instead of having to save up longer initially for the one that probably won't break in ten years?

"stop whining about gas prices and just buy a Tesla. It's way cheaper in the long run"

> Could do an escrow/deposit style thing so you can get your money back if your cheap shit actually doesn't break faster. So there's an incentive to make things cheaper only if you are confident in your long-term business model and reliability.

The capital requirements to implement that would be absolutely out of this world.

Cheap crap that constantly breaks is a poor tax. The difference between luxury prices and cheap prices are not driven by that single crucial worm gear that in plastic costs a penny and in steel costs a dollar. They still would have put in the plastic one if the prices had been reversed.

If people were offered the chance to buy something that would last for a 25-50% premium over the stuff that won't, they'll jump for it. Instead they're offered a choice between crap and heavily marketed luxury items which could also be crap, because their premium is not proportional to the quality of the materials or engineering.

> "stop whining about gas prices and just buy a Tesla. It's way cheaper in the long run"

It would have been better to choose an example that was true.

> at a reasonable price, witch means buying all cost no more than +10% of the assembled device on sale

I get what you’re trying to accomplish here, but as stated, this seems ridiculous. A washing machine may have 75+ part numbers (with many of those having multiples [like screws and panel clips]).

Asking a manufacturer to stock and handle each of them individually for service parts at a loss seems unreasonable. If you bought every part individually to assemble a $25K Toyota, I bet you’d spend over $100K in parts. Why? Because it costs more money to box, label, ship, inventory, pick, and pack a washing machine or a car a part at a time than to load a cardboard box with a whole machine inside with a fork truck or drive a car off a hauler.

> Another fraud is "spare parts available ONLY to 'certified technicians'" witch means repair is as expensive a get a new gear.

It blows my mind that some vehicle repair manuals are basically impossible to find.

Poor quality products are typically cheap. Such a tax will hurt poor people, those who most of all need lower priced products. Poor people will need support in buying high quality products.

Wouldn’t the simplest way to punish selling crap be to bump up the years of required warranty significantly, for most product categories?

Don't some countries in Europe already have this? Minimum warranties because the product must work for X number of years no matter what?

A sliding tax that got larger the shorter the warranty was would be interesting, perhaps avoidable if you showed a certain amount of repairability (or longevity of product model; a device that has been made for five years is going to be more repairable than one that changes every year, if everything else is the same).