Back in 2002, I was getting a package with a brand new Pocket PC (smartphone without the phone, running Windows). And I really wanted to know when it was delivered, but the UPS guy would regularly leave packages on the porch without ringing the bell or anything.
This was before you could get delivery alerts or anything like that. But I had a spare laptop with an integrated webcam (wow!), and I'd figured out how to make it run actions on motion detection.
My plan was to point the laptop at the door, and eject the CD drive when it detected motion. The tray of the drive would push a water bottle off the table. That would land on a seesaw, which would launch a deck of cards in a hard plastic case at the door and make a very loud noise.
It's unclear why I couldn't just play a really sound on the speakers instead. Anyway, I tested the program by standing in front of the laptop and waving my hand.
It worked perfectly! The CD tray ejected, and I watched as the water bottle slowly rolled off the table. It dropped onto the seesaw...... and instantly launched a hard plastic deck at my face and got me right between the eyes.
Never again have I been in so much pain and also so excited about my code working perfectly at the exact same time.
This made me actually laugh out loud, it feels like some of the things I came up with as a teenager wanting to do robotics and automation but having no money or way to purchase things online, water bottles were actually a good way of powering things like opening curtains by dropping them on a string.
Also I like that even after you came up with "knock something off the table" you felt you needed a seesaw catapult thing and didn't just knock something off that could make the actual sound like a cake tin or bell or something.
> Also I like that even after you came up with "knock something off the table" you felt you needed a seesaw catapult thing and didn't just knock something off that could make the actual sound like a cake tin or bell or something.
It totally doesn't make any sense! I think I might have been fascinated with the idea of Rube Goldberg machines or something at the time. Or maybe I thought I could build a "security system" with it? Also it was summer and I was a bored teenager.
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.
> 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...
Recently I did what’s called the ‘big 3’ upgrade on my car’s wiring. You replace the oem wiring from your alternator, etc. with 1/0 gauge cable, thus allowing substantially more power through. This is for speakers. I made my own cables and was in the process of upsizing one of the battery lugs by drilling the hole bigger on a drill press. I was just holding the wire steady with my left hand while pulling the drill handle down with my right. The drill bit caught and spun the cable around, including somehow my hand in it, winding my hand up in the cable very tight against the still spinning drill. It’s a small drill press and didn’t have enough torque to keep spinning, but had the drill been stronger I’d have at least broken my hand if not worse. As it was my hand was swollen and scratched pretty good. When you make your living typing this really makes you think.
Having had this happen a few times, I'm pretty obsessive about workholding now. It's a shame that a good drill-press vise can cost almost as much as the drill press itself, because it's really important for safety.
You should image-search the term "radial drill" sometime. ;)
You don't need a high-dollar Kurt milling vise for a drill press, and you only need to constrain the part in one degree of freedom (rotation about Z axis). Just put a single fastener in your table and drop the slots in that vise over it. Gravity and quill pressure hold it in Z, the table holds it flat against rotation about X and Y, and you want it to have the ability to slide a bit in X and Y to let the drill find the center of your punch/pilot hole. If the drill catches, the torque will push against the stud and it can't move.
An impact driver (rattle gun) is much better for speeding up disassembly than a drill. They also don't apply anything like the same feeling of torque to the operator's wrist.
A lower power (e.g. 300Nm max) battery driver is great for when you have to undo lots of lower sized bolts, while it would be a little bit underpowered for wheel nuts or motorcycle fork retaining bolts.
You should be introduced to Italian single-sided-swingarm nuts. For example, my MV Agusta Brutale required 220 to 240Nm tightening. It would come loose with my battery-powered 300NM rattle gun, but only after a while. (Fantastic bike but I no longer own it. I'd rent another though.)
Ducati single-sided swingarm nuts can be similar, but I have not yet owned a Ducati.
They probably could have, had they been ready for it. Not everyone is the same weight and strength either so it could just be that it was out of their physical capabilities.
That is often the difference between home and tradesman tools. A tradesman can reasonably be expected to handle a bit more responsibility from their tools than the home handyman.
I imagine he was leaning over the engine bay, maybe holding the drill in one hand. So in that specific scenario, the tool was more powerful than he could control.
But that same drill might be asked to bore a large hole in a piece of wood, and the user would anticipate the amount of leverage they need to control it. Two hands, arms close to body, etc.
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.
For a continuous drilling operation the torque is totally fine, the problem is abrupt changes in torque because of something catching. On drills without this feature that's what the torque limiting clutch is for.
Dunno about Bosch's implementation, but the Milwaukee one sucks. The drill/impact driver would strip the screw head, jerk your wrist, and then cut the power. I'd much rather have a mechanical clutch than than that one.
We actually had an older drill with the mechanical clutch with a stripped high gear that we kept around for driving screws instead of tossing because the new one was so bad.
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.
When I drill 30cm holes in fiberglass or wood, I place my leg next to the handle. That have saved my wrist many times as the tool bites to the material and send the drill in a circular motion.
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.
