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> but clearly that's not necessary You are both wrong and contradicting yourself. If it isn't necessary, then complaining about the tools is moot since as you

> but clearly that's not necessary You are both wrong and contradicting yourself. If it isn't necessary, then complaining about the tools is moot since as you wrote yourself, it's not necessary. But, if you design a portable consumer device and you know to what tolerance you need a battery to be adhered to the case to make it not come loose, you know what pressure, movement, adhesive etc. are needed to make that happen for the form factor the battery is going to fit in. You know who doesn't know that? Pretty much everyone who isn't an engineer, and for most people who are an engineer, they might know that these are parameters that exist, but they aren't going to know every variation for every device ever produced. So now that nonsense about it being "clearly" is not so clear anymore. Engineering things to be safe and reliable is pretty difficult. Add in batteries and it's suddenly one or more orders of magnitudes more difficult. That much is definitely clear, because when you cut corners, just guess or think to yourself "it is just a battery and some adhesive, how hard can this be" you get phones self-igniting on airplanes. If we take your full line as a quote: > It's like they just copy-pasted their production line processes, but clearly that's not necessary. Do you really think there are a bunch of people using manual hand tools mass producing every aspect of a phone? Sure, there might be a bunch of steps where manual labour was effective and efficient, but it's not like you show up at the factory with your suitcase of tools and go to work at your desk. What they reproduced is the parameters. And that is exactly what you want. A repaired product should be as close to a freshly manufactured product as possible if you're going to be liable for it.

ghodith 2y ago
> What they reproduced is the parameters. And that is exactly what you want. A repaired product should be as close to a freshly manufactured product as possible if you're going to be liable for it. This has some sense to it, mostly from the liability point of view, but this > if you design a portable consumer device and you know to what tolerance you need a battery to be adhered to the case to make it not come loose, you know what pressure, movement, adhesive etc. are needed to make that happen for the form factor the battery is going to fit in. as someone who works in this field, this is overstating the matter quite a bit. The tolerances for something like pressure in this instance are going to be wide enough that "press firmly" would suffice in a rework document. It's made to be very simple on purpose for manufacturing, and a lot of slop is built in so that we're not in this situation where microns or milli-newtons matter and cause a battery fire somewhere down the line. The fixtures are primarily for efficiency gains, and in that sense I would agree with the gp that press fixtures are not practically necessary in an at-home version of this process.
- oneplane 2y ago
  > The fixtures are primarily for efficiency gains I agree, however, the battery example was a prime candidate for "it is not always as simple as it seems". LiPo batteries don't like getting squished.
  - userbinator 2y ago
    Pouch cells are normally under compression as force is required to keep the plates together. A firm press isn't going to hurt them. If you're applying enough force to actually crush and short the cell, you are far too ham-fisted to do work like this. In fact using a tool to apply pressure is more likely to cause damage.

ghodith 2y ago

> What they reproduced is the parameters. And that is exactly what you want. A repaired product should be as close to a freshly manufactured product as possible if you're going to be liable for it. This has some sense to it, mostly from the liability point of view, but this > if you design a portable consumer device and you know to what tolerance you need a battery to be adhered to the case to make it not come loose, you know what pressure, movement, adhesive etc. are needed to make that happen for the form factor the battery is going to fit in. as someone who works in this field, this is overstating the matter quite a bit. The tolerances for something like pressure in this instance are going to be wide enough that "press firmly" would suffice in a rework document. It's made to be very simple on purpose for manufacturing, and a lot of slop is built in so that we're not in this situation where microns or milli-newtons matter and cause a battery fire somewhere down the line. The fixtures are primarily for efficiency gains, and in that sense I would agree with the gp that press fixtures are not practically necessary in an at-home version of this process.

oneplane 2y ago
> The fixtures are primarily for efficiency gains I agree, however, the battery example was a prime candidate for "it is not always as simple as it seems". LiPo batteries don't like getting squished.
- userbinator 2y ago
  Pouch cells are normally under compression as force is required to keep the plates together. A firm press isn't going to hurt them. If you're applying enough force to actually crush and short the cell, you are far too ham-fisted to do work like this. In fact using a tool to apply pressure is more likely to cause damage.