5 ms·

That's the opposite of reality. More mechanical/moving parts increases risk and complexity, not reduces it. If something is misaligned or bends or breaks or ev

by jjk166 6y ago

That's the opposite of reality. More mechanical/moving parts increases risk and complexity, not reduces it. If something is misaligned or bends or breaks or even if it's just insufficiently lubricated, you're SOL. Solid state transistors are stupid reliable in comparison. Further, implementing more than two or three levels of conditional logic with mechanisms is prohibitively expensive, whereas you can have thousands of checks in a digital system practically for free. Finally, a mechanical system can only handle situations it is designed for, upgrades are difficult and sometimes impossible to implement. On the other hand digital logic is easily updated to deal with unforeseen issues. Electricity is just as much a physical phenomenon as fluid flow or mechanical stress. [Edit] I'm a mechanical engineer, no one should be any more enthusiastic about doing things mechanically than I am.

TheCapeGreek 6y ago
Sure, because taking out the digital system to repair/upgrade it (unless your tap is somehow wireless too) is totally different from taking out these damaged/upgradeable mechanical mechanisms.
- jjk166 6y ago
  If you don't see a difference between updating software and hardware, I don't really know what to say.
umvi 6y ago
I guess the point is... say you use a microchip connected to a sensor to determine when to switch off a gas nozzle. It would work, of course, but if the sensor fails, or there's a bug in the firmware, or if power fails... gas spills everywhere. Whereas if you couple the trigger to a physical phenomenon that doesn't need electricity to work, now there's only one thing that can fail, and that's the part converting the physical phenomenon to a mechanical action. I love computers as much as anyone on this site, but I like mechanical things too. I much prefer mechanical locks to digital ones. Mechanical locks are extremely reliable and well made ones work for centuries. Whereas I wouldn't trust a modern fingerprint padlock at all - what if the sensor fails? What if the batteries run out? What if moisture gets inside and corrodes the circuit board? One of the main jobs of a lock is to open when I need it to, and I just don't trust battery powered locks to do that.
- jjk166 6y ago
  > now there's only one thing that can fail That's the sticking point. People tend not to think of mechanical systems as systems full of many components any one of which can fail, but they are. In the case of the gas nozzle, you have the orifice for the airflow which can get blocked, you have the diaphragm which can break, you have the connection to the lever which can sever, you have the lever itself which can bind. Critically if it does fail, it fails catastrophically - gas spills everywhere. On the other hand consider a system employing a capacitive level sensor. When the sensor comes into contact with fluid, the dialectric constant changes and thus the voltage drop across the sensor increases to the point the valve will close itself. If anything goes wrong, say you lose power or a wire breaks or someone physically rips the nozzle off, the voltage still decreases below the cutoff threshold so the valve still closes - it fails safe. People like mechanical systems because they are easy to visualize, but that's not the same as being simple or safe. At the same time, most of our experience with electronics is with low cost consumer electronics where the price of failure is low and there is strong financial incentive to use cheap components with short life expectancies in configurations that aren't fail-safe, so we tend to associate electronics with being unreliable. But on a fundamental level, the force stopping two gears from passing through each other is exactly the same as the one producing a current when you apply a voltage to a piece of copper.
neuralRiot 6y ago
The problem is overengineering a device just for the convenience of the manufacturer or to add wow factor without taking in account reliability. It happens with mechanical and electrical devices as well. Tesla is not the only or the first to use electrically operated door releases.
- jjk166 6y ago
  It's unclear to me whether you are referring to the specific handle deployment or electronic components in general. If the former, I agree that it seems like a dumb feature but if people want to pay for it, so be it. However if you are talking about electronic systems in general, they are not overengineering for the convenience of the manufacturer nor wow factor. Components like solid state relays are chosen because they are safer and simpler than their mechanical counterparts - the fact that you can do more with them and they are cheaper is just further evidence of their overall superiority for most applications. I think what a lot of people are forgetting here is that in the vast majority of situations you don't want random people to be able to easily open up your doors from outside. What failed here was not the door handle - which operated exactly as it should under normal circumstances, but the emergency override that should unlock the car when the airbags deploy. However, it's completely reasonable for some systems to fail when you crash at extremely high speeds - you can't make things indestructible. I see no evidence that a mechanical failsafe would have performed better.
  - neuralRiot 6y ago
    Everything has its tradeoffs, the problem is what are you willing to give to get what, and I don’t think users know exactly that because systems have become so complex that even engineers sometimes struggle to make the right choices specially when pressured by marketing depts. To me personally i trust more a piece of steel wire than a motor-driver-microcontroller-switch-battery chain. Just for my door handles being able to move in and out.

by jjk166 6y ago

TheCapeGreek 6y ago

Sure, because taking out the digital system to repair/upgrade it (unless your tap is somehow wireless too) is totally different from taking out these damaged/upgradeable mechanical mechanisms.

jjk166 6y ago
If you don't see a difference between updating software and hardware, I don't really know what to say.

umvi 6y ago

I guess the point is... say you use a microchip connected to a sensor to determine when to switch off a gas nozzle. It would work, of course, but if the sensor fails, or there's a bug in the firmware, or if power fails... gas spills everywhere. Whereas if you couple the trigger to a physical phenomenon that doesn't need electricity to work, now there's only one thing that can fail, and that's the part converting the physical phenomenon to a mechanical action. I love computers as much as anyone on this site, but I like mechanical things too. I much prefer mechanical locks to digital ones. Mechanical locks are extremely reliable and well made ones work for centuries. Whereas I wouldn't trust a modern fingerprint padlock at all - what if the sensor fails? What if the batteries run out? What if moisture gets inside and corrodes the circuit board? One of the main jobs of a lock is to open when I need it to, and I just don't trust battery powered locks to do that.

jjk166 6y ago
> now there's only one thing that can fail That's the sticking point. People tend not to think of mechanical systems as systems full of many components any one of which can fail, but they are. In the case of the gas nozzle, you have the orifice for the airflow which can get blocked, you have the diaphragm which can break, you have the connection to the lever which can sever, you have the lever itself which can bind. Critically if it does fail, it fails catastrophically - gas spills everywhere. On the other hand consider a system employing a capacitive level sensor. When the sensor comes into contact with fluid, the dialectric constant changes and thus the voltage drop across the sensor increases to the point the valve will close itself. If anything goes wrong, say you lose power or a wire breaks or someone physically rips the nozzle off, the voltage still decreases below the cutoff threshold so the valve still closes - it fails safe. People like mechanical systems because they are easy to visualize, but that's not the same as being simple or safe. At the same time, most of our experience with electronics is with low cost consumer electronics where the price of failure is low and there is strong financial incentive to use cheap components with short life expectancies in configurations that aren't fail-safe, so we tend to associate electronics with being unreliable. But on a fundamental level, the force stopping two gears from passing through each other is exactly the same as the one producing a current when you apply a voltage to a piece of copper.

neuralRiot 6y ago

The problem is overengineering a device just for the convenience of the manufacturer or to add wow factor without taking in account reliability. It happens with mechanical and electrical devices as well. Tesla is not the only or the first to use electrically operated door releases.

jjk166 6y ago
It's unclear to me whether you are referring to the specific handle deployment or electronic components in general. If the former, I agree that it seems like a dumb feature but if people want to pay for it, so be it. However if you are talking about electronic systems in general, they are not overengineering for the convenience of the manufacturer nor wow factor. Components like solid state relays are chosen because they are safer and simpler than their mechanical counterparts - the fact that you can do more with them and they are cheaper is just further evidence of their overall superiority for most applications. I think what a lot of people are forgetting here is that in the vast majority of situations you don't want random people to be able to easily open up your doors from outside. What failed here was not the door handle - which operated exactly as it should under normal circumstances, but the emergency override that should unlock the car when the airbags deploy. However, it's completely reasonable for some systems to fail when you crash at extremely high speeds - you can't make things indestructible. I see no evidence that a mechanical failsafe would have performed better.
- neuralRiot 6y ago
  Everything has its tradeoffs, the problem is what are you willing to give to get what, and I don’t think users know exactly that because systems have become so complex that even engineers sometimes struggle to make the right choices specially when pressured by marketing depts. To me personally i trust more a piece of steel wire than a motor-driver-microcontroller-switch-battery chain. Just for my door handles being able to move in and out.