machine shop horror stories
 

anybody have any stories of people getting hurt while machining?

any flying chuck keys blinding people, fingers sucked into mills and grinders, etc etc?

Re: machine shop horror stories
 

Or long hair pulling heads into spinning chucks?

No, no horror stories. We Take Care Here.

Re: machine shop horror stories
 

I was once machining 1/4" polycarb on an open CNC router, I think at about 6k RPM. I was cutting out a pocket about 4"x6" square. Forgot to put in screws to hold down the scrap piece. When it finished the cut, the endmill grabbed it and flung it 40 feet across the shop so fast I didn't even see it go. I felt the wind off of it as it flew by. Lucky that's all I felt. It was completely shattered when I found it. Polycarb, shattered.

Be careful out there...

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I remember about 3 years ago(I was a Freshman at the time), and I was drilling into a piece of diamond plate. Being a Freshman at the time, and not to bright in the machining sense; I didn't use anything to lock the plate down. To add to this initial dilemma, I unknowingly was drilling a bit too hard into the plate, and ultimately the plate got stuck in the bit, causing the plate to spin with the bit, resulting in my hands getting badly cut.

Fortunately, it has been a few years since my last machining accident and I always let incoming freshmen and members of my past ignorances.

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Not a machine shop per say...
I work for an aircraft engine manufacturer, pictures have been circulating around the office this week of an incdent that happened at an air field where a mechanic trying to save his hat got sucked into an engine on wing. I WILL NOT share these pictures, it is worse than you imagine.

Re: machine shop horror stories
 

Luckily our team has been basically devoid of serious injuries, but there is one former student turned mentor who practically needs to be followed around with a first aid kit for all the minor cuts, scratches, and burns he manages to give himself. I will not give his name as a courtesy.

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Also not a shop, but I was patching the floor pan in my jeep. Cut a piece of sheet metal and was holding it with pliers. Turned to grab gloves (good for welding) and caught the back of my hand on the freshly sharpened edge. Lets say I could see parts of my hand I shouldn't have been able to see.

I have a good 3 inch scar going from the middle of my and to the first knuckle of my index finger. Probably should have gotten stitches, instead dumped rubbing alcohol on the cut used a few butterfly band-aids as well as plenty of medical tape and went back to welding.

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When I was taking a shop class in college, the lathes were back to back in rows. I was just lucky enough to drop something on the floor (tool or drawing). As I bent to pick it up, the guy at the lathe in the next row turned it on with the chuck handle in place. It went flying overhead where my head and upper body had been. I am alive today because I can't hold onto things. (They don't let me climb towers either.) Needless to say, that guy failed the class.

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I was taking a shop class at a community college, and we were all tramming in mill heads. Somebody turned on the mill to move the sweep bar to the other side (you're supposed to just grab it and swing it). 18" long sweep bar... gauge on the end... spinning at whatever the mill was set to. This lasted a couple of seconds at the most before somebody got to the power switch, but the damage was done.

Nobody got hurt, but the gauge was ruined, and the student didn't come back after that, whether by his own choice or by the instructor's I don't know. I found the needle at the near end of the shop; I think the glass or part of it was near the chip bin near where I'd been a few minutes earlier.

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It was in woodshop, and someone (I don't remember who) was sanding a piece of wood on an oscillating vertical sander, when it caught and was flung into the top of a nearby band-saw. Thankfully the band-saw had a large upper structure so the wood hit only it - and not any person. But it was Loud.

Now, in Robotics, there haven't been any serious incidents, just the usual scrapes. Ironically, First Aid is in the cutting drawer...

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Well... No serious injuries... But I busted my knuckle open with a wrench while doing some lathe work. Did I get a band-aid? Hahaha no. I just kept wiping the blood on my pants. I really wanted to get that part done!

Re: machine shop horror stories
 

We've had a girl get her fingers broken in a gearbox.
There was another story (not on our team), either last year or the year before, where a girl got her hair caught in a machine, managed to not get her face pulled in because her hand got pulled in first. She tried to pull her hair out with her hand, which got pulled into the machine with her hair and she lost most of her fingers.

Re: machine shop horror stories
 

Someone, somewhere was filing down an good sized chunk of metal on a belt sander-like device and lost his grip sending the part about 15 feet across the room missing his son's head by about half a foot.

Re: machine shop horror stories
 

Way way back at the dawn of time when our team was young... (10 years ago) We got to build in the machine shop at the Land Machines Division of Brown & Root. AND they let us use their nice lathes and mills. With those nifty speedy chuck keys and everything. Then there was the day we all heard a gigantic bang from the lathe area. High speed flying chuck keys are terrifying and loud when they hit the wall. But that wasn't what got use restricted to spring loaded safety keys. It was the second time the key was left in the lathe and (luckily) stayed in long enough to be violently slammed into the ways and visibly bent. So yeah, everyone please remember that lathes are one of the most dangerous machine tools you'll encounter. And keep your hand on the chuck key whenever it's in the chuck. If you never let it go till it's out of the chuck, it's stupendously less likely to take flight.

Unrelated to FRC, but we recently had a close call at my workplace. A welding positioner about the size of the attached photo was being anchored to the concrete when one of the anchors failed and the whole thing fell forward, narrowly missing one of our shop hands. Obviously an extremely serious incident and we're making some changes around the shop to prevent any reoccurrences. So any of you working in industrial shops, do remember to be wary of the big machines around you.

Re: machine shop horror stories
 

I am that guy on my team sadly... I think its just a bad luck thing... I take every precaution and I end up hurt.. 3 times this week sadly...

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!

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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.

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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..

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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.

Re: machine shop horror stories
 

Well, nothing serious happened to us, but during my rookie year, I was milling a circular piece of aluminum the old fashioned way and while turning the knob, I managed to scrape my thumb against the edge of aluminum. It bled quite a lot and I learned that I should start wearing gloves a lot more.

As for this season, one of our seniors was working on the lathe, cutting down a cast iron pulley and accidentally cut too much in one pass, sending a large chunk of cast iron flying by his head. He was safe, but was quite embarrassed seeing that we had to order a new one.

Re: machine shop horror stories
 

This thread is why I don't machine things.

Re: machine shop horror stories
 

But do you drive a car?

I don't know the statistics, but how many people get seriously injured from machining things, vs how many people how don't?

Re: machine shop horror stories
 

A simple look at "number of injuries" wouldn't really suffice as many more people drive cars for longer periods of time than stand in a machine shop.

When machining, if you forget something critical you can do some major damage very quickly, a lot more than in a car. I am totally the kind of person who would forget to clamp something down or have a part kick back on a table saw - hence I avoid machining.

Re: machine shop horror stories
 

I have only ever used a lathe twice. One of the two times, I left the key thingy in and it flew out. Not good.

Being a programmer, I generally don't do precision machining (mill and lathe), but will make small parts - generally to mount electrical components. They generally aren't that perfect, but they are good enough for electrical components.

Re: machine shop horror stories
 

Or anything else, for that matter. From the two or three times (over four years) I've accidentally had the key fly out, I'm convinced that the chuck key exiting the chuck also creates a terrifying bang.

I can't echo this enough - I'm my team's main lather operator, and I've learned that those things are horrendously dangerous. Chuck keys are one among the many things that can go flying if the operator isn't careful. Please also remember to make sure that whatever is chucked up is in there TIGHTLY. If you start cutting and hear a clunk, stop the lathe and check to make sure the metal (or PVC, or plastic, or whatever you're cutting) hasn't slipped. Make sure that the material is in there straight, and that EVERYTHING is squared up. You definitely don't want your material to slip out and hit you in the face. I'm sure it hurts.

One more lathe safety thing: even though we don't want chuck keys flying at all, make sure that the area in front of and behind the chuck are clear. Nobody should be standing in the area in front of and behind the chuck, including you. Take a step to the left or right before you turn the machine on.

----

I've had a few close calls myself, but thankfully nothing horribly bloody. Freshman year, I managed to tear off about a quarter of my fingernail on the lathe, and I'm still not entirely sure how it happened, but I think my finger got hit by part of the chuck somehow. I also currently have some small burns from hot metal chips hitting my skin. It's painful.

I was also drilling a hole in a piece of extruded aluminum that I had clamped in a vice, and the drill bit got caught on the metal. It spun the entire vice around and took a good amount of skin off of my left wrist, which was the hand that was holding the vice. No blood, but it was very painful, and I still have the scar. Always clamp things down to the table when working with machinery!

Re: machine shop horror stories
 

no injuries on the team but I did shoot a metal shard into my eye when i was cutting some sheetmetal for my car with a grinder it was sticking in there pretty well but after a few rinses it did come out the dumb part is that i had the glasses right next to me

Re: machine shop horror stories
 

This didn't happen in robotics but my sophomore year in metal shop me and a buddy were using the acytelaine torch to heat up what would become a crowbar and a fire poker, respectively. I finished before he did and was cleaning up when he came up to me and asked my opinion on whether it looked evenly pounded. Me, being smart, decided that this piece of metal warranted a closer look, so i grab the piece of metal, which I found out was still hot. I had burn marks all over my hand after that.

LESSON: if something is being held with vice grips, do not grab the piece of metal with your bare hands.

Re: machine shop horror stories
 

EDIT: for bonus points mark the point in the story where you know whats about to happen.


In the summer of 2006 we got our first (and currently only) mill. its a 10.5"^2 3 axis CNC techno Devinnci (its small its cheep but its our baby so please be kind). Well in the fall we do BEST so we used the BEST robot as a test bed for our new mill (we ended up making plywood omni wheels). So we had sent one of our mentors to training down in San Antonio and we felt OK to turn it on and start to cut. As BEST only really allows plywood and plastic, and doesn't give you much plastic, we started with plywood as our first cut. We set the mill up to how our mentor was trained and started to watch it go. Now at this time I should mention that our mentor was trained on this mill using brass and light steel, so we had the head speed turned all the way up the travel speed all the way down and were using like a 8 flute bit.

About 5 min in ( or 3 in in to the cut) the student monitoring the mill (in BEST the students have to do 100% of the work, but they do allow mentor guidance) noticed that the mill started to smell really really good like a pine forest in spring. We took a look at how the cut was going saw that there was just a pile of saw dust forming and no large chunks flinging off , it was rather unimpressive. We felt confidant enough to open the door and further "investigate" the pine fresh sent. As we opened the door a draft blew the pile of saw dust in to the air . . it was at this point as the dust mixed with the new air and aided by the very hot bit that most of the part ,as well as the aspirated saw dust, caught fire.

we have since moved to a 4 flute bit. turned the head down, increased the travel speed . . and got a vacuum attachment. We have had no further flame ups.

Re: machine shop horror stories
 

Chris, if I can do it anyone can.

I always have someone else double check the set up before I do anything more complex than use a bandsaw. We also have a rule where no one works alone on anything so oversights are pretty rare, we've had a few times where things come loose but nothing flying across the shop.

I have to disagree with your comment about the car. I drive a small car (2800lbs) but it'll do 0-60 in sub 7 seconds. Do some quick math on that, 2.5 tons moving at 60mph compared to a lathe chuck key. You screw up in a car and someone is just as dead as if you embed a lathe chuck key in their head. All you can do is follow the appropriate safety precautions. Don't operate under the influence, don't horse around, focus on what you are doing, and respect the machine. For the longest time I was afraid of the mill, a couple years ago I had to get over that and now I have a healthy respect for it. Until about 2 hours ago I was nervous about using a lathe but turning out a couple pulleys and I got over that.

For those of you who don't want to read a block of text:

Respect the Tools.

Re: machine shop horror stories
 

Quite a few are just funny with no serious injury involved (although one or two are pretty nasty).

Here's a funny one; the other day I was using a grinder up on an a frame ladder and it caught something and flew out of my hands and went flying around on the floor (it was locked on) for a little bit till it shut off when the lock on disengaged. I only got a little scrape from a chunk of wheel that hit me, I had gloves on and had my hard hat w/ shield on, that stopped me from taking a hit to the face so safety does pay off.

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A professional machinist at a local shop left a chuck key in a high speed lathe and when it flew out it killed the guy it hit :eek:

When my team worked in this shop we never had any accidents save one: a friend of mine was turning down an aluminum sprocket when the lathe chuck fell off. At 1000+RPM. Turning towards him. Thank god the part shield was down, no doubt it saved serious injury. One of the mentors who worked in the shop said "I've never seen so much damage done to a lathe" and fortunately the incident was deemed not his fault.

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Circa 1978 shop class. I was using a table router. I was using the fence the wrong way reaching over the fence holding the piece against the fence. In the last 1/4 of the groove was making was a knot. It grabbed the knot, spun the piece of wood around, taking my thumb into bit. The board shot off of the table hitting a kid in the temple, immediately knocking him out. I ran, turned off the emergency power. Checking on the dude, someone said hey r3P0 your hand is bleeding. 3 inside stitches 9 more to close it up. The dude that got hit received a free concussion from the event and a goose egg the size of golfball!

But wait there is another story from same highschool ( who has an team so I will not mention where I went to HS). We had an upper level gas welding shop. A kid was playing on the lift that takes the tanks up to that level while it was going up. No Chain connected, he slips and to catch himself he pulls a full O2 bottle off the lift from the second story with no protective cover over vavle. When it hit the concrete the "rocket" was born, the tank moved a workbench about 3 feet, ricochets off that through the garage door and screamed across the field hitting the elementary school about 100 yards way. Need less to say, I think OSHA came into the HS and we all got to watch the safety videos again. ( Old timers know the videos I'm talking about)


Always intense!
r3P0

Re: machine shop horror stories
 

I just remembered one that happened to me in the off-season in our team's shop during school. It was first hour and I had a study hall, in the previous year all our welders graduated and I was the only student left with a basic understanding of welding, so naturally I had to practice for build season. As I finished a weld and pulled up the mask I dropped the welding stick (I was TIG welding) and tried to catch it. If you have ever TIG welded before you know this in itself is not a bad thing but on my way down I managed to plant my hand on the aluminum part that had been basically a liquid only seconds before. I had some cool 2nd degree burns but being a boyscout I was used to getting these without any kind of way to treat them so I just went on my way to my next class.

Re: machine shop horror stories
 

wow...badass haha

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Not to single you out, but I think there's a bit of a lesson here that bears mentioning. I can appreciate that maybe you felt that there really was nothing to be done about the injury, and you'd made up your mind that you might as well not waste time obsessing over it. On the other hand, given that first aid for burns is pretty straightforward—why didn't you administer it or seek it out? Generally the first step would be to cool the affected area with water for a few minutes.

(I'm not saying that I haven't shrugged off a minor injury before—sure, of course I have—but I shrug them off after taking the standard first aid precautions.)

No, not exactly. If you think it is, you're unwittingly contributing to the problem.

Report the injury to someone trustworthy and level-headed, ideally the supervising teacher. Although granted, it may not have been a consideration in your case, it's surprising how easy it is to do something that triggers symptoms of shock—and when that happens, as a precaution, you want someone observing you while you go about the rest of your business. And even if shock isn't a concern, there are numerous practical reasons to report it.

In a workplace that takes safety seriously, there's no retributive action taken for getting injured and reporting it. Hopefully, your school would have been enlightened enough to be able to chalk it up as a lesson learned, without banning you from using the welder, or some other overreaction. After all, that would only encourage you not to report it the next time.

Re: machine shop horror stories
 

Me too. I don't even go into the shop to take photos.
Ignorance is bliss.