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?

Or long hair pulling heads into spinning chucks?

No, no horror stories. We Take Care Here.

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…

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.

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.

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.

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.

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.

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.

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…

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!

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.

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.

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.





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…

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.

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

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.

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.

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.