5 ms·

Anything with an actuator, really. I'm a controls engineer, we work with all kinds of hazards and it's my responsibility to run the risk assessment that makes s

Anything with an actuator, really. I'm a controls engineer, we work with all kinds of hazards and it's my responsibility to run the risk assessment that makes sure no minimum-wage operator gets harmed because of our machine. People are the squishiest, weakest, most sensitive part of just about any shop, so there's a lot of risks to assess! One key observation, though, when working with code is that the machine becomes so close to predictable that it's more dangerous than if it were unpredictable. A cordless handheld drill is hardly a tool that most people would call 'hazardous'. You turn the trigger, the thing rotates, grab the chuck and you can likely stall it. But that much energy in something driven by code is extremely dangerous, it's waiting for any of who knows how many conditions to take off, a common one is that putting your hands in/on something that seems to be not moving can 'make' a sensor and the machine will take off. There are definitely two kinds of safety domains, one applies to manually operated tools where the operator of, say, a knife is responsible for their own safety - if they cut themselves, they're at fault, not the knifemaker. There's another kind of safety engineering where if the machine takes off 'by itself' while an operator is in the way it's the machine designer's fault for not stopping that from happening, the operator can't be expected to know what's going on. The latter should become more common as computers continue to permeate everything we use - that cordless drill is no longer controlled by the operator with a trigger switch that connects power to a DC motor, it's a brushless motor driver with an analog input sensing the position of the trigger and the EMF of the motor, and the charge state of the batteries, and who knows what else. Bump a sensor and it might take off, you don't know why it does what it does. I'll continue to make my automated cells as safe as I can, but don't trust code that's not so simple you can be confident of how it works.

dharmab 5y ago
> A cordless handheld drill is hardly a tool that most people would call 'hazardous'. You turn the trigger, the thing rotates, grab the chuck and you can likely stall it. But that much energy in something driven by code is extremely dangerous, it's waiting for any of who knows how many conditions to take off, a common one is that putting your hands in/on something that seems to be not moving can 'make' a sensor and the machine will take off. A friend needed a valve cover gasket changed on his Honda, and his wife needed to use the car for her Uber runs that night. He came over and instead of our usual hand tools I put a socket adapter on my 20V drill to speed up disassembly. I handed the drill to him and told him "start on the lowest torque setting, and move up in small steps." I turned around to grab more tools from the toolbox. A minute later, I heard a loud noise. I turned to see the car's windshield cracked and a shocked look on my friend's face. My friend was used to his renter's power drill. He hadn't anticipated how much torque a modern contractor's drill outputs and set the torque to the maximum setting. On the third valve cover bolt, the drill had caught on the bolt head and spun my friend around, smashing the battery into the windshield. There's a piece of paper taped to me toolbox called "List of things <friend's name> may not attempt unsupervised." It gained a couple of entries that day...
- whatshisface 5y ago
  Why would a drill be engineered to put out more torque than a human holding the handle could be expected to counterbalance?
  - dharmab 5y ago
    For drilling holes in soft materials like drywall and wood, or even softer metals like aluminum. I recently used that drill to drill into a motorcycle engine to remove a stuck rotor cover. Relevant old article: http://www.team.net/mjb/hawg.html http://www.team.net/mjb/hawg.html
  - duskwuff 5y ago
    Powerful electric drills will often come with an extra handle on the side (or a mounting point for one) so that you can brace them with both hands. It's up to the user to set an appropriate torque limit if they're only using one hand.
    - maccard 5y ago
      Using the analogies above, a drill like that could put the trigger on the awkward handle, forcing the operator to use it
      - dharmab 5y ago
        The second handle sometimes needs to be removed to fit into a narrow space. In that case, you set a torque limit and operate the drill with one hand.
        maccard 5y ago
        That's fair; Maybe you need to hold two triggers, and the torque limit is reduced if you're only operating in "one hand mode"?
  - function_seven 5y ago
prox 5y ago
One of the reasons I love to dable in the game Space Engineers is that you get to experiment with simulated physical equipment. Things often go wrong and boom (or Klang in SE parlance) and you often die or hurt yourself. You seen learn to program in steps for safety.

dharmab 5y ago

> A cordless handheld drill is hardly a tool that most people would call 'hazardous'. You turn the trigger, the thing rotates, grab the chuck and you can likely stall it. But that much energy in something driven by code is extremely dangerous, it's waiting for any of who knows how many conditions to take off, a common one is that putting your hands in/on something that seems to be not moving can 'make' a sensor and the machine will take off. A friend needed a valve cover gasket changed on his Honda, and his wife needed to use the car for her Uber runs that night. He came over and instead of our usual hand tools I put a socket adapter on my 20V drill to speed up disassembly. I handed the drill to him and told him "start on the lowest torque setting, and move up in small steps." I turned around to grab more tools from the toolbox. A minute later, I heard a loud noise. I turned to see the car's windshield cracked and a shocked look on my friend's face. My friend was used to his renter's power drill. He hadn't anticipated how much torque a modern contractor's drill outputs and set the torque to the maximum setting. On the third valve cover bolt, the drill had caught on the bolt head and spun my friend around, smashing the battery into the windshield. There's a piece of paper taped to me toolbox called "List of things <friend's name> may not attempt unsupervised." It gained a couple of entries that day...

whatshisface 5y ago
Why would a drill be engineered to put out more torque than a human holding the handle could be expected to counterbalance?
- dharmab 5y ago
  For drilling holes in soft materials like drywall and wood, or even softer metals like aluminum. I recently used that drill to drill into a motorcycle engine to remove a stuck rotor cover. Relevant old article: http://www.team.net/mjb/hawg.html http://www.team.net/mjb/hawg.html
- duskwuff 5y ago
  Powerful electric drills will often come with an extra handle on the side (or a mounting point for one) so that you can brace them with both hands. It's up to the user to set an appropriate torque limit if they're only using one hand.
  - maccard 5y ago
    Using the analogies above, a drill like that could put the trigger on the awkward handle, forcing the operator to use it
    - dharmab 5y ago
      The second handle sometimes needs to be removed to fit into a narrow space. In that case, you set a torque limit and operate the drill with one hand.
      - maccard 5y ago
        That's fair; Maybe you need to hold two triggers, and the torque limit is reduced if you're only operating in "one hand mode"?
- function_seven 5y ago

prox 5y ago

One of the reasons I love to dable in the game Space Engineers is that you get to experiment with simulated physical equipment. Things often go wrong and boom (or Klang in SE parlance) and you often die or hurt yourself. You seen learn to program in steps for safety.