Chuck Key

[Alb]

Hi All,

Hope this helps
My brother got a chuch key bounce off his cake hole Lucky for him is was a drill chuck key
With that in mind when i got my md65 lathe the first thing i did was braze on a washer about half way down the shank of the key then stuck on a spring from a bycicle pump so that you have to push the square into the chuck and if you let go it will just spring out ;D

James

 

[Sparticusrye]

About 3 years ago. I had the person operating the lathe infront of me on the shop floor leave his key in and turn on the lathe. I heard a scary woosh as it flew over my shoulder. I took his chuck key and put a spring on it with a retaining ring. So now it won't stay in the chuck without his hand on it. The lathes in that shop were set on a slight angle which is probably what saved me.

I never take my hand off the key when in use. That was too close for comfort.

 

[Paulsv]

I have a bell hanging outside the shop. Just loud enough to get my attention over the loudest machine in the shop but not so loud it scares the bejeezes out of me. There is a sign asking folks to ring the bell before entering, and the bell is far enough from the door to give me a good 5 second warning. I have not been startled since installing it.

When I built my basement shop, my wife laughed because I used a set of French doors as the entrance to the shop. She thought I was trying to be stylish, but I really just wanted to be able to see or sense anyone that was about to enter the shop when I was using a machine, especially the table saw, which scares me a lot worse than metal working machines.

 

[picclock]

I always make it a habit to rotate the chuck by hand before turning the machine on. This prevents unintended tool crashes and as the key will not clear the ways prevents the chuck rotating.

Seems to work for me.

picclock

 

[tornitore45]

I never had a problem with forgetting the key in, so far.
My problem is to find it when needed, sometime I have in the hand after losening a part and walk away from the late, put down the key pick up another something...

It was so bad with the little drill press key that finally I chained it. Is not as handy but can be too far.

 

[mklotz]

I've seen those chuck keys with the auto-ejection springs. It would drive me crazy(ier) to be forced to use one. I'd grind that spring off the first time it hopped out of the hole when I needed that hand to make an adjustment.

The best approach is to mount a microswitch at the bottom of the tube which you use to hold the wrench when it's not in use. Wire the microswitch in series with the tool (lathe, drill press, etc.) so the wrench has to be in the holder for the tool to operate. A side benefit of this approach is that you'll always be able to find the wrench the next time you need it.

 

[tornitore45]

The spring that came with the chuck key was removed instantly and saved in spring bin, you never know when you need a spring.

They are unpractical.

 

[user 284]

I have no doubt this is going to sound like I'm an uncaring know it all. That's not what I'm trying to give for an impression and you can think about my points however and whatever you'd like because I'm not about to change what works for me.

I run and have run mobile construction and mining equipment for about 40 years. Some of it has weighed up to 2,000 tons. There's no safe guards on this equipment and any operater can easily damage the equipment or injure and even kill himself or others. You work your way up in this business. Have I made mistakes? Of course, Thankfully none very serious. But you learn to do an automatic check list and grow a third eye in the back of your head. For some equipment like rope shovels and excavators, A few items to visually check on that list might be done 600-1,000 times in a 12 hour shift.

I can't recall exactly where I read it, But I think it was in one of George Thomas's books. "It's just as easy to learn good working habits as bad". So on most hobby size equipment it's pretty easy to make a full rotation on the chuck checking for clearance on our lathes, mills and drill presses. I've bought a few drill press chucks with those spring loaded chuck keys and I've removed the spring on every single one.They really are useless and a joke. They do more damage to the chuck and key teeth than their worth due to being forced out of engagement as their rotated. A simple 10 second visual check along with a designated hanger for any chuck key should take about 3 days for a inexperienced operater to learn to use for a lifetimes habit. Even when I'm 100% positive my clearances are fine, I ALWAYS rotate that lathe chuck one revolution just as a check before hitting the power switch. That way I never make a mistake about forgetting to do so when or if there is a clearance problem. In my industry you don't get cut any slack for forgetting the basics. In fact your judged more than very harshly. I also don't cut myself any slack for forgetting those basics in my shop either. Microswitches, spring loaded keys etc are fine as an idea, But you will never 100% outwit true stupidity or lack of attention to detail. Better education about safety and personal shop habits will do far more than all these "safe for the incompetent" systems ever will.

A dead simple checklist that works for how you do takes just a few seconds and after a bit of time you don't even think about doing it.

So do my methods work? I've yet to forget a chuck key. And up to now I've never run a cutting tool or the carriage parts into a lathe chuck or a tool into a milling vice or the table. You can explain all these chuck key dangers in a brand new post every single day, But if a person won't learn or understand about the safety issues? Sorry, But I just don't have a lot of sympathy for them. For some items in life? "I forgot" really isn't an option or a reasonable excuse.

Pete

 

[chrsbrbnk]

Kind of the other side of the routine I was holding the chuck key in my hand on a hardinge hlv toolroom lathe operating the chuck when an allen wrench fell out of the tool holder, hits the forward lever which turns the machine on slamming my hand and chuck wrench against the side of the head stock. really hurt and scared the crap out of me.

 

[bezalel2000]

U gota Love all those safety devices.

It seams that every time they invent a better "idiot-proof" safety device, we manage to find a better class of idiot. :-\

 

[mgbrv8]

A while back I was the "Lucky" person in the shop to teach a safety course. The people in the course werent machineist they were engineers i being an engineer and raised as a Machinist by my tool and die maker father know that engineers can be difficult at times. Needless to say they thought they knew everything but in fact they knew nothing. There was this one guy that was so mechanically inept that it was unbelievable. He left the chuck key in and turn on the machine on four occasions now this is on a hardinge HLVH of all things. I was not allowed to throw him out. but I did duck tape the chuck key to his hand for the rest of the day. needless to say he was perturbed but he didn't leave the chuck key in for the rest of the day and he learned his lesson.

David Hetrick

 

[Boot]

Never leave a wrench or lead hammer on a miller table when using a facing cutter in the horizontal position. I launched a 5 lb. lead hammer to the ceiling in my younger days. You will learn the safty rules real quick. Boot

 

[Tin Falcon]

As many of you know I was trained as a Machinist By the USAF . At the time the school was at Aberdeen Proving ground MD.We shared the school building with the US Army And navy/Marine corps. The lathe lab was a shared class room there were several row of lathes and each service branch had there assigned section of the lab. Safety was a big thing at the beging of each class section no student was allowed to cross the yellow line until sleeves were rolled up safety glasses on and a safety given a student had to read the rules to the class. The chuck key rule was strictly enforced. A safety violation during a practical test was automatic test failure.
The army took a different tact on the chuck key rule . someone had machined a giant aluminum chuck key IIRC it was about 2 foot long and the handle about the same length. Any violator had to carry the thing around for the rest of the day it did have a leather strap on it and I did see it being carried .
I do like the duct tape to the hand Idea.
Tin

 

[steamer]

I've seent he chuck key on a chain hanging around the neck for a day Tin.

 

[neptune769]

I went to a vocational High School for machining. We were taught that once that chuck key goes in the chuck it's part of your hand until you remove it from the chuck. When I was a Junior a Freshman left the key in the chuck. The shop teacher caught him so he taped it to his hand. Of course he didn't run a machine like that. Wait it gets better. Another freshman did the same thing. So he got a key taped to his opposite hand. Then the teacher took the guys free hands and taped a single wood 2x4 between them. Now the Carpentry shop was at the other end of the school. The teacher sent the guys there to have the 2x4 cut in two. Needles to say they never left the key in the chuck again. At least while was there. :big:

Regards,
Dennis L.

 

[rake60]

The Shop Teacher story brings back memories.

When I'm using a hand file on a lathe, I would sometimes hold the file handle
in my right hand and the front end of the file with my left hand.

BAD PRACTICE!

If that spinning chuck clips your left elbow you may be festering bone chips out
of it for the rest of your life.

If the shop teacher saw you doing that, he'd calmly ask you to shut the machine off.
Then he would rap your left elbow with his 12" scale.
Then he'd say:

"That had to hurt. Just imagine how much more it would have hurt if the chuck had hit you!
Don't be stupid in MY SHOP!"

Rick

 

[Ken I]

Some of those "old school" teachers had some tricks to make you remember.

I had a woodwork teacher that if he caught you "choking" a hammer (holding it near the head) - he would issue you with a hammer with a 5" handle - it was yours until he caught someone else doing it.

It became progressively harder to get rid of the damn thing as time went by... lesson learned.

I launched one chuck key early in my carreer - smacking it into the bed, ruining the key & throwing the headstock out of whack - I was made to fix it - long story I've told before - I haven't done it since.

Ken

 

[pcw]

i remember back in school. chuck-keys didnt have the safety spring like modern day keys have. we HAD to place the key in special holder on the lathe otherwise the lathe wouldnt turn. was just quite simple pvc pipe with switch in it. worked very well.

 

[Admiral_dk]

I had my formal machineshop training back in 1979 and the shop had rows of Myford lathes and two big German/Swiss ?) lathes with extremely powerful motors that would go from a dead stop to 3000 rpm i a 1/4 of a rotation and stop in the same distance.

Our teacher warned us about the chuck key : "I have warned ALL my student the last 30 years about the hazard of leaving the chuck key in the chuck and there has ALWAYS been at least one in each class that either didn't listen or forgot the warning ...!!!!... Well I hope that telling you this true story about a very unfortunate / fortunate student from the class of 1978 - a year ago now - he forgot the chuck key in the (brandname of the big machine), had it set to 3000 rpm's and pressed start, Because of the extreme acceleration on these machines, the chuck key left the chuck after a 1/4 of a turn and hit him straight in the forehead with only the handle being left on the outside of the scull !!!!.... I dialed 000 (911 back then in Denmark) and was told to leave the chuck key undisturbed and they would send an ambulance immediately .... Well he survived and will have a permanent brain damage and by some good fortune will be able to function on a disability pension for the rest of his life - Now can I get you ALL to promise me that you NEVER forget the chuck key in the chuck ??!!"

Well I never forgot the story, maybe partly because I was using one of the two big lathes and I hope that I never will forget the chuck key in the chuck.

 

[digiex-chris]

another one I ran into (well, ran into me) yesterday is just as dangerous. I've got a relatively little lathe, takes some time to get up to any reasonable rpm, and I'm still in the "repeat things enough to make them a good habit" phase. I hit start, and something smacked me in the chest giving me a cut right through my tshirt. I thought it was the chuck, but no, it's right where I always put it, right under the on button. Looked at the chuck, but no my workpiece was still there. Looked around the shop, and found the culprit. I was setting up a squaring off job in my 4 jaw chuck, using a piece of 1/2" square by about 4" long tool steel blank as a parallel between the chuck face and the little block. I'd tapped the work down against it, so it didn't fall out when I let go of it. I'd meant to remove it, but it slipped my mind. Possibly a little more dangerous because it's not in the same brain space as the chuck key. Setting up a job like that is not something you do every time you turn the machine on.

I've also had parallels vibrate out from under the work in the milling vise and fall on the floor too. I have no doubt that would hurt getting caught and flung. I've started taping checklists to my machines that flop over the on button so I've gotta look at the checklist enough to lift it and hit the button. Since I'm the only one using the machines and I'm dedicated to making the safe practices second nature, this is working well for me.