4 ms·

A friend of mine told me once about working at his family's bowling alley after school one night and suddenly having his shirt ripped off him by one of the sett

A friend of mine told me once about working at his family's bowling alley after school one night and suddenly having his shirt ripped off him by one of the setting machines. He said it was sobering and he felt lucky he didn't go with it.

viraptor 3y ago
This feels so weird. The machines don't need to put that much force into the usual operation. We know how much the arm/scoop weights and the usual resistance the pins can give... So why would there be instances of people being crushed? We've got mechanical ways to restrict the force - what are the issues preventing adding that to the design?
- malfist 3y ago
  Pins are pretty heavy, and the machine needs to throw them around pretty quickly
  - SteveNuts 3y ago
    I'm surprised they don't have failsafes that would stop it immediately if it suddenly has an extra 130+ pounds of load
    - TylerE 3y ago
      The common models in service haven’t really changed much since the 1970s.
      - usrusr 3y ago
        I guess this is also the reason for the dangerously strong forces involved: lots of outputs (surfaces that move pins) powered from few big motors because there's hardly any control besides synchronisation through gears. If the market was big enough to support the adoption of robots arms to the pin setting use case there would be neither strings nor danger from old string-less machines.
        fsckboy 3y ago
        robot arms are quite strong and pretty dangerous when "on task" Chess robot breaks seven-year-old boy's finger during Moscow Open https://www.bbc.com/news/world-europe-62286017 https://www.bbc.com/news/world-europe-62286017
        TylerE 3y ago
        Industrial robots are far more dangerous as they can typically move fully in 3d, whereas an old mechanical system like these… yes it has a gazillion pinch points and minimal guards, but at least each movement will only do one thrust by (eg stroke back and forth or spin).
  - viraptor 3y ago
    They're 1.5kg and the machine slides them, not lifts. Even if it did need to put exactly that much force to lift them, 15kg is really unlikely to kill you - toddlers keep jumping on parents without murdering them.
    - johnwalkr 3y ago
      I recommend watching a video[1] about how these things work. I really don't see how it's feasible to make this complex, heavy machine inherently safe to stick your arms in. And keep in mind these machines have been iterated on for 100 years or more by multiple companies. Modern ones are full of safety features, but they revolve around lockouts, not making everything so weak it can't hurt you. [1]https://www.youtube.com/watch?v=Iod6uwUGM2E https://www.youtube.com/watch?v=Iod6uwUGM2E
      - ikari_pl 3y ago
        thank you. I've only ever seen the string ones, and was wondering what is the older system
    - AndrewKemendo 3y ago
      I don’t understand this attitude Everything shown in the industry backs up the claim of its dangerousness to the point where this entire article revolves around an industry changing in order to make up for that. Why would you, somebody who is not in the industry and has absolutely no clue about this, have an opinion this strongly held?
      - viraptor 3y ago
        This was not an opinion about the machine or industry. I asked why the forces are necessary exactly because I don't know that part. I disagree with the response about the pin weight, because I've got enough clue about mechanics and safety to know it's very unlikely to be a full explanation. The lifting happens either on a conveyor or the lift/harness. We have existing systems that can ensure you don't crush people with the weight itself this way. The dangerousness may come from different parts like higher torque motors, or exposed parts, or programming issues, or ... So feel free to comment on that if you know the answer.
- johnwalkr 3y ago
  There's elevators, gears, levers, belts and chains and stuff in there. Pinsetters are full of pinch hazards and move multiple pins and balls around at the same time. It's not a trivial amount of force, especially if you consider how the tension in a chain translates to a crushing force if you get in between a sprocket and chain, or how the the force in a 1m long arm lifting a 1.5kg pin translates to a crushing force at the centre of rotation. Not to mention the machines are beefy and have to withstand parts of them being hit by 10kg bowling balls. A quick google search indicates a pinsetter machine weighs more than a ton. You could easily lose your shirt, finger or get your hoodie strings caught in there. You'd have to be unlucky to die but it's happened. "Just restricting the force" doesn't work because the force at pinch points will be huge in normal operation and the extra force to slice your finger off at a pinch point would be noise compared to all the other forces.
- aleph_minus_one 3y ago
  I also ask myself: why isn't the pin setter machine always completely powered off when any maintenance is done? If this does not suffice, add a photoelectric barrier that immediately cuts the power of the pin setter machine if it is crossed by some maintenance personal.
  - exclusiv 3y ago
    Valid question but the reason is the mechanics in the back are usually a salty kind (and some drink a LOT in the back) and they'll get a call to fix a lodged pin or something and decide to not turn the power off and bad things sometimes happen. I knew one back in the day that ripped up his arm really bad and had to take a lot of time off.
    - JohnFen 3y ago
      In those cases, the fault isn't the machines, it's the negligence of the mechanics. Where I work, we produce industrial machines that could rip you in half without a hiccup. As a result we (like all industries that use hazardous equipment) have a very strong lock out/tag out policy. I remember in training they warned us that at customer sites, it's common for the customer's employees to be averse to LOTO because of the time and hassle involved, and they may try to pressure us to skip LOTO procedures. We are expressly prohibited from doing so, but the negligence is real.
      - exclusiv 3y ago
        100%. My father in law has spent a lot of time in industrial space and he told me they setup dual buttons for some machines so you are required to press them both with both hands. This prevents them from having a free arm at risk. You have to prevent people from going rogue, otherwise they will.
- dendrite9 3y ago
  Johnwalkr had some good reasons. The machines are old, with gears and belts to transfer motion not something made with separate motors for each motion. I never saw the specific machine I am mentioning but I wouldn't be surprised if protective parts of the machines stayed off to make it easier to fix malfunctions. The machines were designed at a different time. I've been in the back of a few alleys as a kid and they seemed a few steps, but not that many, beyond the shops where all tools were driven by belts from the ceiling. For example power looms severely injured people in a time before they were designed with safety guards and that's just moving thread>

viraptor 3y ago

This feels so weird. The machines don't need to put that much force into the usual operation. We know how much the arm/scoop weights and the usual resistance the pins can give... So why would there be instances of people being crushed? We've got mechanical ways to restrict the force - what are the issues preventing adding that to the design?

malfist 3y ago
Pins are pretty heavy, and the machine needs to throw them around pretty quickly
- SteveNuts 3y ago
  I'm surprised they don't have failsafes that would stop it immediately if it suddenly has an extra 130+ pounds of load
  - TylerE 3y ago
    The common models in service haven’t really changed much since the 1970s.
    - usrusr 3y ago
      I guess this is also the reason for the dangerously strong forces involved: lots of outputs (surfaces that move pins) powered from few big motors because there's hardly any control besides synchronisation through gears. If the market was big enough to support the adoption of robots arms to the pin setting use case there would be neither strings nor danger from old string-less machines.
      - fsckboy 3y ago
        robot arms are quite strong and pretty dangerous when "on task" Chess robot breaks seven-year-old boy's finger during Moscow Open https://www.bbc.com/news/world-europe-62286017 https://www.bbc.com/news/world-europe-62286017
        TylerE 3y ago
        Industrial robots are far more dangerous as they can typically move fully in 3d, whereas an old mechanical system like these… yes it has a gazillion pinch points and minimal guards, but at least each movement will only do one thrust by (eg stroke back and forth or spin).
- viraptor 3y ago
  They're 1.5kg and the machine slides them, not lifts. Even if it did need to put exactly that much force to lift them, 15kg is really unlikely to kill you - toddlers keep jumping on parents without murdering them.
  - johnwalkr 3y ago
    I recommend watching a video[1] about how these things work. I really don't see how it's feasible to make this complex, heavy machine inherently safe to stick your arms in. And keep in mind these machines have been iterated on for 100 years or more by multiple companies. Modern ones are full of safety features, but they revolve around lockouts, not making everything so weak it can't hurt you. [1]https://www.youtube.com/watch?v=Iod6uwUGM2E https://www.youtube.com/watch?v=Iod6uwUGM2E
    - ikari_pl 3y ago
      thank you. I've only ever seen the string ones, and was wondering what is the older system
  - AndrewKemendo 3y ago
    I don’t understand this attitude Everything shown in the industry backs up the claim of its dangerousness to the point where this entire article revolves around an industry changing in order to make up for that. Why would you, somebody who is not in the industry and has absolutely no clue about this, have an opinion this strongly held?
    - viraptor 3y ago
      This was not an opinion about the machine or industry. I asked why the forces are necessary exactly because I don't know that part. I disagree with the response about the pin weight, because I've got enough clue about mechanics and safety to know it's very unlikely to be a full explanation. The lifting happens either on a conveyor or the lift/harness. We have existing systems that can ensure you don't crush people with the weight itself this way. The dangerousness may come from different parts like higher torque motors, or exposed parts, or programming issues, or ... So feel free to comment on that if you know the answer.
johnwalkr 3y ago
There's elevators, gears, levers, belts and chains and stuff in there. Pinsetters are full of pinch hazards and move multiple pins and balls around at the same time. It's not a trivial amount of force, especially if you consider how the tension in a chain translates to a crushing force if you get in between a sprocket and chain, or how the the force in a 1m long arm lifting a 1.5kg pin translates to a crushing force at the centre of rotation. Not to mention the machines are beefy and have to withstand parts of them being hit by 10kg bowling balls. A quick google search indicates a pinsetter machine weighs more than a ton. You could easily lose your shirt, finger or get your hoodie strings caught in there. You'd have to be unlucky to die but it's happened. "Just restricting the force" doesn't work because the force at pinch points will be huge in normal operation and the extra force to slice your finger off at a pinch point would be noise compared to all the other forces.
aleph_minus_one 3y ago
I also ask myself: why isn't the pin setter machine always completely powered off when any maintenance is done? If this does not suffice, add a photoelectric barrier that immediately cuts the power of the pin setter machine if it is crossed by some maintenance personal.
- exclusiv 3y ago
  Valid question but the reason is the mechanics in the back are usually a salty kind (and some drink a LOT in the back) and they'll get a call to fix a lodged pin or something and decide to not turn the power off and bad things sometimes happen. I knew one back in the day that ripped up his arm really bad and had to take a lot of time off.
  - JohnFen 3y ago
    In those cases, the fault isn't the machines, it's the negligence of the mechanics. Where I work, we produce industrial machines that could rip you in half without a hiccup. As a result we (like all industries that use hazardous equipment) have a very strong lock out/tag out policy. I remember in training they warned us that at customer sites, it's common for the customer's employees to be averse to LOTO because of the time and hassle involved, and they may try to pressure us to skip LOTO procedures. We are expressly prohibited from doing so, but the negligence is real.
    - exclusiv 3y ago
      100%. My father in law has spent a lot of time in industrial space and he told me they setup dual buttons for some machines so you are required to press them both with both hands. This prevents them from having a free arm at risk. You have to prevent people from going rogue, otherwise they will.
dendrite9 3y ago
Johnwalkr had some good reasons. The machines are old, with gears and belts to transfer motion not something made with separate motors for each motion. I never saw the specific machine I am mentioning but I wouldn't be surprised if protective parts of the machines stayed off to make it easier to fix malfunctions. The machines were designed at a different time. I've been in the back of a few alleys as a kid and they seemed a few steps, but not that many, beyond the shops where all tools were driven by belts from the ceiling. For example power looms severely injured people in a time before they were designed with safety guards and that's just moving thread>