I had a chuck key, which I had my hand on. try and bite me........ 14 inch Clausing with the hydraulic speed control, well, I was new to machining and at home with my cute lathe.... thought I could just bump the chuck a quarter turn for some reason... well, that key came around with my meathooks on it and when it hit the way, the square drive on key broke off and the lathe kept on turning.....I was very lucky to have not broken my arm...... scarred the poo out of me for sure, and I learned a very valuable lesson... love all your videos John...... best wishes from Florida, Paul
I seen a chuck key swing and hit the way and break off the square. Lol... Now, I have seen handles on top of a Bridgeport get flung a ways after beating up the top of the machine. Lol Can you do a test with a tighter fitting chuck key? It should break or bend the key and depending on the ways it'll dent or polish them 😂😂😅 Side note: you guys are fawking awesome! Lol. This, IMO is by far the best video to date. This is classic machinist humor heckling the hecklers. LOVE IT!
The reasons I always heard were not necessarily throwing the chuck key, but it hanging on long enough to pinch or grab some clothing and drag you in, or with a long handled key smacking into the bed ways and flinging from there, (presumably getting a lot of energy from the flexing of the shaft, presumably with a big geared head lathe that would just keep turning right through the key and not stall out)
OK, Lets talk about something us junkers like . Your shop yard, I see a lot of cool stuff that could be interesting projects. A little look around would be nice. I'm in Georgia so not to worry about me slipping in after dark. All kidding aside, Your channel is the first one I look at every day. Thank You for having it. Educational and entertaining for me. Now I'm headed out to my shop. Have a healthy day.
When I was starting out learning on a lathe, I had the misfortune of leaving the chuck key in the chuck, a couple of times. Given the size of the lathe compared to my stature, generally I set the key between 10:00 and 11:00. Most every time I made the blunder of leaving the key in the chuck, it would slam to the floor right about directly in front of the lathe. I did get hit once after the key ricocheted off of the ways. It hurt like hell but didn't do any lasting or serious damage. The worst experience I had in the machine shop was with an old style tig welder. They had a big (red) AC/DC welder, with a High Frequency box on top. This thing utilized a foot peddle with a huge rheostat that was about 16" in diameter with no shielding. The boss put me to tigging up some dipole shields for a navigational system that was the forerunner of GPS. About middle of the day, the repetitiveness of doing the same task got monotonous and I stopped paying attention long enough to lay my leg against that rheostat. Needless to say, I no longer wondered what that high Frequency box did to that welding current. I had been shocked a couple of times stick welding, but that tig rig was the worst shock I've ever had. That high Frequency current will make you taste your fillings in your teeth.
Always been more worried about drawbar spanner’s seen a few helicopters in the workshop although they never flew off. With our apprentices I always liked to instil some fear of the machines so they didn’t get cocky, probably why these stories are so common.
When I first started at a machine shop, we had a big lathe with a bent chuck key handle. I was told that the boss had done that many years ago. I was admonished to never leave the key in the chuck, yada, yada, yada. A year or two later, we got a new chuck for that machine. I got it all installed and dialed in. Finally, a straight chuck key. Within a week or two the boss was doing something on that lathe and next thing I knew I heard this bang and turned in time to see the chuck key fly up maybe 3 or 4 feet and land on the top of a tooling cabinet. The lathe was running really slow and there wasn't clearance for the key, so it hit the carriage and snapped off the square part neat as can be. Still didn't have much energy, but startled me and the boss. New key was junk so I had to pull out the old bent one and use it the rest of the years I worked there. This is why we can't have nice things.
I threw a chuck key in school. Machines were all at an angle so the chuck/headstock of mine was in line with the operator behind me. Who happened to be one of two cute girls in our engineering program. It hit the floor and slid right between her feet with enough speed that hitting her would have been bad but probably not terrible and then it hit the next machine behind her on the leg of the tailstock side. The look I got when I turned around was very memorable. I have never left a key in a lathe since. I still think about it every time I use one 15 years later. I was probably running around 600RPM would be my guess.
Almost exactly the way I saw it happen in tech school. Next guy along the row forgot to take it out, starts up the spindle, and it makes a big bang and goes skittering off across the floor around my ankles. Wakes you up, makes it clear why you ought be wearing steel toes, but not exactly the 8 windows story lol.
Saw one launch further than these just a couple of weeks ago, from a little old 3 foot bed Craftsman lathe, with enough force to knock some teeth out. It has to do with acceleration speed and key mass and balance, as well as how tight it fits in the chuck.
The real dangerous situation is with a tighter fitting chuck key that is left in with the machine turned on-that does not initially come out…but spins up fast and shoots out upon the chuck completely accelerated.
Thanks for posting this. It should also be pointed out that most of your really dramatic flings were with the key in the 3-4:00 position when in reality it would almost always be left in the 10-12:00 position.
It is seemingly the surprise that makes it more shocking to the senses. I wonder if some of the more extreme examples involved the chuck key pinching against other lathe parts and the spin up rate varies, as you showed.
Hello for Scotland, When I was an apprentice one of the worst crimes that you could commit was leaving your chuck key in. You soon got used to putting it in your pocket every time you left the lathe or one of your workmates would put it in for you and wait until you were at the other side of the shop before shouting as loud as they could, "Jon, you've left your chuck key in!" The apprentice school foreman must have had high blood pressure, can you imagine being in charge of forty sixteen to nineteen year old boys and as many dangerous machines? I recently bought some lathe chucks, one is a Cushman chuck and has got me scratching my head. I have put it on RU-vid, 'Unusual lathe chuck'. I would very much appreciate it if you could have a look at it and throw a bit of light. Thank you, Jon
Yes, I am familiar with them. The first ones I know of in the US were made by Buck Chuck Company 1940s-50s?. I used one at my first industrial machinist job, they became popular for a short time in the later 70's to the early 90's, as CNC made them less expensive to build. You could set a eccentric condition, then repeat it quickly, they didn't stay put well though & needed tweaking often.
Hi John Made me laugh with the reality applied. Someone (you would know him)here years ago Left chuck wrench in 17” lathe and snapped off .575 square stub off factory chuck wrench. I don’t know what speed he was doing. Some of these lathes have a pretty fast start up like Regal LeBlond , Clausing Colchester. Good video DP
I’ll add that I was hit in the jaw and chest in high school machine shop class. We had smaller lathes with 6” or 8” chucks. A lighter chuck will spin up quicker. That’s why drag racers use titanium rims instead of steel. Also the lathes were angled approx 15 degrees which aligned the next lathes operator with their chuck! Also 5 foot spacing. I can also see a lighter/smaller key that fits well as being thrown the furthest.
The other thing is that inexperienced people are more likely to use a smaller lathe, which would spin up much faster, and launch the smaller chuck keys with a greater velocity. I will admit I have done that. No damage beyond my pride.
I agree the lighter lathes are most dangerous for throwing. Never did it on the Clausing but my 9X20 Chinese lathe(with a lightweight key) launched over my left shoulder once and hit the sander or something on the opposite side of the 2-car garage. I do remembering knowing better and was surprised at the force. It hit the other side before I realized what it was. That lathe sits pretty high so I shutter to think what that would have done to my teeth. As far as just not standing in front of the chuck, I agree, however, if someone will neglect to remove the key, they will likely forget to not stand in front of the chuck. Accidents are seldom caused one mistake but by multiple mistakes coming together. I certainly wouldn’t call this busted or “a lie” if only from what I saw with a small hobby lathe. Again, best practice.
I did this when I was new, and what the video shows is exactly what happened. My boss got after me about leaving the key in the 4th axis on the mill. I had it at the 12 o clock position and left it in there overnight to remind me it wasn't tight and still needed aligning. I'm the only one who uses this old mill these days. My boss comes in early and turns it on to warm up the electronics, because its old and finicky. He never, ever, has homed the machine for me. Apparently this morning he decided to, and was homing it and somehow didn't notice the key in there until the last second and almost crashed the machine and destroyed it...
Speaking of stuff flying and potentially getting someone hurt pretty bad… the shop I work in, years before I got there one year ago, an arbor cutter got put in a mill backwards and/or loose, and when he started the cut the screw backed out and sent the probably 6”x1/8” cutter clean across the shop and a couple guys saw it go by pretty close to them. Got told that story the first time I ran a part that needed a slit cut in it and I’ve made dang sure to triple check the direction of everything ever since.
The one lathe I wouldn't dare test is an older Haas TL1. It's a servo spindle, yet is a hybrid CNC/Manual lathe with no shields. It can ramp up to 2000 RPM from a dead stop in less than a second. But to be fair, I'm more worried about not clamping my part well enough. That is terrifying.
That’s a very dangerous experiment! I’m going to need to take that lathe off of your hands so you guys don’t get hurt!😳🤣😬🔥🙌 Joking aside, thank you for this video! You all are awesome!
this gave me the biggest chuckle. i dont wanna be on the receiving end of any of those chuck keys though. good advise not standing in the line of fire for sure. lol
You were looking for the correct term for throwing keys .. it's obviously called CHUCKING keys ! And hello from a fellow shop and mill in the upper peninsula. Michelle
When I was around 12 I slung one across my dads shop, nobody was around nobody hurt. But it came out of that chuck extremely fast and it hit the wall very hard about 20ft away. I would guess in this case it could have really hurt someone. So all the variables were just right on my experience. But it really left a lasting impression on me and I've never done it since.
Chuck key should have a home. My friends outside of work at training age didn't understand the danger. But turning on power what direction does your body move. Straight into the line of fire. My guard was dropped after a previous night's celebration. Coffee helps.
I once had a chuck jaw on a wood lathe come out at 1000rpm which made me jump out of my skin. It was an old double-ended lathe where you could turn on either the inboard side (over the ways for you metal folk) or on the outboard side and I would leave a chuck on the outboard side, I think because it was threaded onto the outboard side it was spinning technically in reverse to how it would conventionally and it unwound the scroll over time to the point where the jaw was ejected. I've always been a chuck key skeptic. Even if the chuck key was ejected from a lathe with a 12" chuck that could instantaneously start at 3000rpm, it would be travelling at around 100mph which is not dissimilar to what a top-level professional baseball pitcher could throw. At a more realistic 1000rpm with the same lathe it would only throw it at around 35mph which a child could achieve by throwing it. There's a reason you never see any real examples or health and safety case studies of this thing happening, because it doesn't happen and people make up long tales.
HAHA, I support this video. I have to admit, I often wince when I see those comments on forums and such and think to myself, "Did it REALLY go through a brick wall though?..." 🤣😂
I don't think science will get in the way of internet experts. Personally I think the key should always be in the chuck. That way you get used to checking the chuck has clearance before you turn it on. Of course that is heresy, but I do what I like in my own shop.
Your demonstration debunked one of my most cherished warning beliefs. I still don't want to get hit and will still follow the no chuck key left in the chuck best practices. I did get to see the effects of unsupported stock stickout of the back end of the lathe spindle. It bent 90 degrees and then broke off. No one got hurt, but it did some impressive damage when the brken piece flew through the shop. It seems to me that the unsupported stickout was about 24". Another similar unexpected accident of this type happened to my 2nd shift maintenance tech. He was prepping to rig a Blanchard grinder alone. He was jacking one end if the machine with a 2x6 yellow pine block on top of a jacking air pillow. The bottom edge of the machine casting was very narrow at that location. It cut the 2x6 in half accross grain and sent the sheared end of the 2x6 block to the 24' high roof decking ceiling. The 2x6 dented the steel decking. I arrived shortly after the event to continue the machine relocation task. He was still shaking and was very pale. This jacking technique was standard practice and had never previously seemed in the slightest way dangerous. Most machine base castings in our shop were inches wide and jacking forces only made an indentation in YP blocking. Weeks prior to my industrial employment a workpiece was thrown out of a lathe. The workpiece went through the CNC lathe enclosure landing 2 machines away. The machine enclosure had been patched, but the scar was pretty impressive. I gained some early respect of what a lathe can do. My new boss was involved in the lathe repair and he was a believer in the power of a lathe. He made me a believer. A frequent repair on our Burgmaster CNC milling machines (vintage mid 1980's) involved disassembling the ATC claws. Spring tesion held the claws closed. The coil springs were stacked with a smaller diameter spring inside a larger spring. The nominal 10" long springs were preloaded to about half their relaxed length and secured with a counter bored nut. The nut had about 3/4" of thread. To compress (preload) the springs a length of 1/4-20 all thread was threaded onto the back of the jaw via the drilled hole in the securing nut and the ID of the coil spring stack. The disassembly procedure to relax the spring preload was to "simultaneously" back a jam nut on the all thread while removing the retaining nut. I was frustrated by the tediousness of this process, so I backed the all thread jam nut to allow about .100" clearance and loosened the retaining nut. When the retaining nut fully unthreaded it couldn't have had any more than the .100" free travel, but it slammed into the jam nut with enough force to stretch the all thread nearly 1". It made a surprising amount of noise in my face. The all thread didn't break, but there was a lengthy section of stretched threads that were nearly broken. I have often wondered how far that nut could have flown if not retained? We do lots of things routinely in the shop that are on the verge of real danger. The actual accidents demonstrate how close to the safety margin normal practices can be. I am like most industrial experienced techs and I am pretty jaded by the safety nazis, but I have experienced enough life changing events personally and second hand to respect the risk of the stored enegy and power that we work with. I am disappointed that the lathe chuck key lethal threat is so exaggerated. Has anyone tested the knocking over a welding cylinder missle threat? One safety video we had to endure showed a tank missle crashing through an office wall and head strking the boss. The boss injury prompted a room full of employee chuckles and cheers.
Hear me Out Maschinist Training Story : Germany Year 2010 . Manual milling Maschine course. We had a Cast Iron square Key to Change Tools in the Manual milling Maschines ..the Attachment Point was at about Head height. Guy on the mill next To me Changes in a 3mm drill Sets the gearbox for max max rpm of 2500 and hits Spindle Forward. The 3 pound Key Starts Spinning and then Release into the the Office cabin of the teachers. Trough a Window into the Backwall nearly and i really mean nearly Kills our instructor. He was Kater fired for not looking after us and because of His booze Problem. Was His Last day in the Job and nearly the Last of His Life. Stay save .
Mention was made of a machine that would not turn off. Due to warmth and then cooling cycles of the electrical contactor condensation can form on them under certain humidity conditions causing corrosion in the contactors. This can cause them to stick in the engaged position after the stop button is pressed and power dropped to the coil. The contactor can usually be taken apart, cleaned up, lubed.
This Lathe has multiple problem, the control harness was smashed, then Freddy Flinstoned together, the contactors are good. It also has some twisted shafts & broken gears.
@@HOWEES Freddy Flintstoned would mean that you're using rocks and sticks to fix it. Anyway, what I mentioned is the most common cause of why machines that use the 'start - stop' type of control circuit for engaging motor contactors to stick 'on' and punching the stop button eventually no longer makes them stop. Fairly dangerous situation. It goes for all kinds of machines with this control, saws, drill presses, you name it. As an aside a damaged wiring harness would not cause the stop button in the start stop circuit to no longer stop the machine. If the wire becomes broken, the start button can't start it to begin with because power flows thorough the stop button. If the wiring is somehow shorted to something else you're going to have a problem where the run contactor picks itself due to getting voltage from a different source than where it should.. The start button won't have the control of the motor to begin with.
@@fredflintstone8048 I fully understand, And stuck contactor point can be a problem, I had not noticed Your user name before🙃. I would say Rube Goldberged would have been a better description. If the Contactor had been stuck, the foot switch would not shut it off either. I might make it into a welding fixture, if We do it will get all new control wiring.
@@HOWEES I mentioned one common cause for contactors to tend to stick in the closed position, the other can be that the worn contacts can sometimes weld when they close. This can of course also happen with manually operated switches. I grew up watching the Flintstones and got a kick out of how everything was made with rocks, logs, and animal skins. I also like how they had Fred start and stop his car, and the way his car would keep going after he got it moving. I also learned a bit of adult humor in how they handled Fred and Barney's marriages in the cartoons.
I did work with a guy that had his finger tip pinched off by a chuck key in 1978. He was tightening the chuck when the compressed air hose fell down and hit the start lever. His finger got pinched between the chuck key and ways.
I was just about to comment that I would expect the risk of a crush injury to be far higher, especially if the key was a snug fit, and you seem to have provided the only real injury evidence so far. (Though to be fair, I haven't read all of the comments.) I guess that may be an argument for leaving the gap out of the bed if so equipped? 😂
Yeah, I saw his finger tip was missing and asked what happened. The shop owner at another place I worked, his fingertip was also missing. They say he was removing burrs from a thread and wasn't running the lathe in reverse. It threaded his finger tip in and twisted it off.
Another good one 👍🏻. I never had problems with chuck keys I think mostly cause I had good teachers and safety training however when I went to work for a machine shop where I was mostly working alone until various employees joined one at a time. I was using a mill near the wall and someone was using a large lathe behind me and he forgot to remove his stop (a 5 inch piece of hardened steel) from behind the workpiece in the chuck so when he started it at a fast spindle speed it flew out past my head and my machine and hit the wall and bounced all over the place. When I turned around to look at him he had this stupid like on his face and didn’t even apologize.😂 I don’t think it had enough energy to crack my thick skull but I’m sure it would’ve hurt might had cracked my coconut though.
I had a small clocksmith lathe, i left the key in and when i turned it on it hit me in the face.... i then could not find it as the key was somewhere on the floor.
Try it with a tight fitting (new) chuck key in a small chuck that can swing over the bed. Three phase DOL start motor. I agree with the line of fire comments. Dont like running a lathe any size without apron controls and a foot brake. I also remove all chuck guards immediately, for safety.
You did enough tests with the chuck key handle vertical to the spindle but never tested it when the handle is parallel to the spindle and can bind though...
The spawner from my Jacobs chuck on the bridge port almost spawned my wrist and went 10ft at 1000 rpm when I switched out a drill and went from the break on the spindle to the on switch.
Realistically a chuck key ejected from a spinning chuck is not going to have enough energy to really hurt someone, the actual dangers are damage to the lathe's ways and clothes/body parts getting caught. It's good practice to remove the chuck key, especially if there's people walking around or you're stepping away from the lathe. Any lathe big enough to grab you and pull you in should just have a safety cover over the chuck, which stops you from inserting the key while it's down and stops the lathe from turing on while it's up
I actually sent a chuck key flying forgetting to remove it, it didn't do any dmg, but it might hurt someone. I'd be more worried about if it didn't fly out and instead spun around and either broke off or broke the machine
So what are the rules of the chuck key throwing contest? Lathes okay, people okay, cannons? What about size of chuck key? Does it have to be found or just mark a target? =)
Not sure, first we need to get enough people that are interested in coming to Fox, Alaska for the event. 3 events tentatively, distance with lathe chuck key not over 3? pounds, not under 1? Free throw by hand, standardized chuck key weight of 1.5? pounds, then the gun powder/air/etc. cannon event , that would be depth of penetration into the hillside.
We had a guy pushing something out of a bore,with a 50 ton press, must have been a bearing or a bushing, but he decided to use a hardened bolt or spring pin and that thing shot across the shop like a bullet !! It left a nice dent in the block wall. I swear that thing would have went right through a person. ALWAYS use a non hardened pusher on the press. At least you can see it bending and theres time to react.
I mean... its still a terrible idea, and my training is screaming at me right now lol, but also I wonder if a smaller chuck would throw it farther (kenetics and speed etc) still though, having a chuck key wallop me beside the head will get the S kicked out of someone... (my Skills Center had a series of holes in the concrete block notably behind the lathes... we were told it was from chuck keys? made sense at the time)
I was setting up a through head stop for some parts over the weekend and turned the lathe on to check the stop alignment and didn't realize the key was in the chuck and it came down and smacked my ways... 😥 So your scrapping that lathe because of a power control issue?
This Lathe has multiple problems, the control harness was smashed, then Freddy Flinstoned together. It also has some twisted shafts & broken gears, if we get more shop space it might become a welding fixture.
There's a lot of liar/narcissists out there exaggerating their stories apparently. It's nice you have some free time to have a little fun up there in Fairbanks. If I get up to Alaska again, I would love to stop in and see your operation.
Worse than 😮 this demonstration is the stacking of steel parts on a surface grinder's magnetic chuck and impinging them to the rotating grinding wheel; then when the grinding wheel has come up to speed throwing the lever to the magnetic chuck and watching the load fly off at high speed into the far wall.
back when i was new too machining (still am by many people standards :p) i accidentally left the chuck key in the CNC lathe and it flew out of the chuck and hit the enclosed door, it would've hit me if i didnt have the doors closed
@@austinpaxman503 You close the guard over the chuck key (yes this works, i've seen it done). Now the key can't fly out and will jam somewhere on the bed of the machine. Now the idiot who put it there will try to pull it out with the machine still on. Bang, arm's gone!
@@reinermiteibidde1009sounds like that chuck guard needs the switch that keeps it from turning on if it isn’t down, that is if your trusting a guard and not the user. But yeah, trusting gimmicky safety measures is more dangerous than not having them and using your brain to me.
I think the chuck key launching competition should be divided into two classes. It should be with and without a vfd. 60hz or whatever ramp rate and frequency you can manage.
In the spirit of your suggestion, We could have both A stock class, and modified class. I think the inverter advantage would be small. The inverter would need to over speed the lathe, and then a quick mechanical clutch to have an advantage, a different set of belts would do the same thing. The clutch design would be the more important hot rodding.
@@HOWEES Would it be legal to lighten the chuck a huge amount and add weight to the rotating parts on the motor side of the clutch? Maybe there should be a regulation chuck key provided by the sanctioning body (NLRA) to keep people from adding weight and golf ball dimples.
@@HOWEES The clutch should use dog engagement rings or something similar. Imagine getting prints from a customer to make a replacement shaft for an old southbend lathe and they specify vascomax 350 for the material because they keep breaking anything less.
Short answer, no. Machinists use their brain as the most important safety equipment. Often one needs to do some finishing operation close to the chuck and the guard would make that even more dangerous than it already would be.
Moral of the story dont piss off your co-worker and might not get a chuck key thrown at you... now for their accuracy this sounds like its in question.....
Just a beautiful place you got there... really don't mind the rough appearance of the yard but I like the location .. in rural area where you can focus on your work. Anyway, thanks for putting an end to all those comments about chuck key in chuck being extremely dangerous.