machine shop horror stories

[alex334]

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.

[Chris is me]

This thread is why I don't machine things.

[nighterfighter]

Originally Posted by Chris is me

This thread is why I don't machine things.

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?

[Chris is me]

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.

[apalrd]

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.

[Karibou]

Originally Posted by Kevin Sevcik

High speed flying chuck keys are terrifying and loud when they hit the wall.

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.

Originally Posted by Kevin Sevcik

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.

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!

[KC1AJT]

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

[flippy147852]

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.

[Stuart]

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.

[Andrew Schreiber]

Originally Posted by Chris is me

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.

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.

[JDL]

Originally Posted by Al Skierkiewicz

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

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.

[JamesCH95]

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

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.

[R3P0]

Originally Posted by unionylibertad

anybody have any stories of people getting hurt while machining?

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

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

[Henry Williams]

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.

[unionylibertad]

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.

wow...badass haha