Re: machine shop horror stories
 

The other day, my boss, while showing a group of students from the team how a surface grinder works fired a sprocket into a wall about 10 ft away. We had anticipated the risk though and everyone was standing well back. They now have a beautifully waterjet oval sprocket as a reminder to respect machines.

Re: machine shop horror stories
 

a few years ago someone was using the mill and the wrench up there, the mill spin it up to 2400 rpm and then it shot off the top, nobody was hurt but it traveled about 100 feet across the shop

Re: machine shop horror stories
 

One of our teammates was working on a scissor lift prototype and accidentally dropped it on his finger. Cut it really deeply, maybe all the way to the bone. Never let programmers near metal.

Re: machine shop horror stories
 

Here are some related threads from deep in the archives (not all are entirely about machining):

team emergencies
First Injuries
Grady personal injury avoidance tip #2
Injuries
were there robot related injuries on your team?
pic: When Waterjets Get Nasty
pic: Waterjet nastiness Dermilogical Effects -face
FIRST Injuries
Serious Safety Incident - Please read to your teams

In grade 7 or 8 shop class, someone* nearly did the same to me. He was using a drill press with a fixed cable or chain tied to the chuck key, presumably so as not to lose it—that's an idiotic convenience feature, by the way—and managed to forget the key in the chuck. Upon starting the drill press, it of course got tangled, then broke off and went flying at the spot where I'd been kneeling to pick something up a few seconds before.

Fortunately, an average drill chuck key can't do as much damage as an average lathe chuck key, so I would have been in rather less danger. He didn't fail; the embarrassment was probably sufficient to cement the lesson.


I've done something close to this—as a high school student working rather late one evening to finish off a robot. In my case, all that resulted were a few little scratches and bruises, rather than cuts. It had a lot to do with not realizing that a drill bit (especially a dull one) would catch on to the rough edge at the bottom of a hole in an aluminum plate. This caused it to lift up when I finished drilling the hole out to its finished size. So of course, the 4 in × 8 in × 0.25 in gearbox plate that I'd been working so hard to finish got picked up by the drill bit, unbalancing it; that wobbled around at a few hundred revolutions per minute for a second or so (hence the shallow and essentially bloodless scrapes on my hands), and then sheared the drill bit off, sending the plate glancing off my chest and into a pile of detritus underneath another piece of machinery. I was in no way seriously injured. Despite that fact, that's not a mistake I aim to make again.


Speaking of mistakes I don't aim to make again, avoid leaving the wrench on the drawbar nut of a Bridgeport 2J2 knee mill. No injuries that time, because fortunately the spindle could only advance a half-turn before the wrench hit the motor housing and unseated itself loudly, falling straight to the ground. Like a lathe chuck key, thats a piece of equipment that should not leave your hand while engaged in a moving part, and which deserves to have a well-defined place in your line of sight when you're reaching for the power switch. (This milling machine—like most—was not set up that way: the wrench lived on the right-hand side of the machine, behind the quill lever and partially obscured by the digital readout, while the power switch was located on the upper left of the mill head.)

*He has a ChiefDelphi account, although he didn't at the time.

Re: machine shop horror stories
 

I have some good ones from my real world job (electrician).

Now on our team no, even though I'm accused of being to lax with team safety (I really don't see why people feel the need to tell the guy how works on live switchgear and around industrial equipment all the time how to handle safety but whatever). No flying chuck keys, no eye injuries, no entanglements, just the occasional splinter and minor cut.

Re: machine shop horror stories
 

JDL,
Someday I would like to hear some of those stories in person.

Re: machine shop horror stories
 

It's not exactly a horror story, but mentor Lyle described (video) how he put a scribe through his thumb! Yuck!

Re: machine shop horror stories
 

Using the belt sander four years ago on a tiny piece of wood. Can probably guess what happened, but the wood got sucked between the table and the belt, along with my fingers.

Had a nice sized hole in 8 of my nails for about a month, and its still kinda sensitive. Lucky for me the teacher/mentor forgot to change the belt that day and it was an old belt, not as rough.

Re: machine shop horror stories
 

Today, I was preparing to cut a piece of plastic for a spacer (tough plastic, can't remember the name)and I was going to use a hacksaw to do it. One of our mentors cam up to me and asked why I was using a hacksaw and I said that it was the easiest and safest way to cut the plastic. He then told me to go and use a compound miter saw, for which we only have a wood blade. I informed him of this and he still said I should use the miter saw. I went and tried. The plastic snapped and whizzed across the room, narrowly missing one of my teammates. Thankfully, nobody was hurt and we were all wearing goggles. Just goes to show you: sometimes, mentors don't always know best.

Re: machine shop horror stories
 

Last year a mentor accidentally "punched" the chuck of our lathe while it was turned on. Bloodied up his knuckles a bit, nothing serious.

Re: machine shop horror stories
 

Exact thing happened to me on Friday night except it hit me in the stomach... No damage done besides a huge bruise and a bit of blood..

Re: machine shop horror stories
 

My team has been pretty good about this (knock on wood) but last week I sent part of a lathe (I forgot the actual piece name) flying at my mentor while welding the tip of the blade to the metal I was cutting into. I also broke a tip off, sent a wheel flying off the lathe and cracked a wheel from tightening it all with in 3 hours of each other. No one was hurt in anyway (unless you count my ego.)

:/

Re: machine shop horror stories
 

This did NOT happen in robotics (thank goodness.... a million times)
nor to someone I know...
and I'm not a hundred percent sure of how it happened, but
Someone in a woods class in my school was cutting on a table saw...
Either he reached for a piece of wood near the blade, or tried to cut a piece of wood two short....
Lost a finger, and a half a finger, and a half a thumb, presumably in the fashion of the picture, one straight cut...
Moral of the story : Don't cut small pieces, use a pushstick, and turn off saw to get scrap out.. Please... :(

Re: machine shop horror stories
 

Last week one of my teammates was drilling into a sheet of aluminum and he didn't clamp it with anything so the whole thing spun around and caught him just below the waist and the whole team just started laughing::ouch::

Re: machine shop horror stories
 

Not really in the shop, but I was at a regional competition 3 years ago. I bent down to pick up our robot after a game and caught my arm on the end of a machine screw. Naturally, it was not a clean cut. It actually looked pretty cool, it had jagged edges on either side of it. I now have a scar on my right arm a few inches below my elbow. It's mostly faded now, but you can still faintly make out where I got cut.