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Safety First
« on: July 07, 2011, 01:13:49 PM »
Hi Guys

Having just read a recent post about operating Estop button with mouse, I thought I would add my advice to that of many others who say that you really must have a hard wired emergency stop switch which is easily accessible, cuts off all power to spindle and drives and is independent of software.

I have 30 odd years experience as a machinist and should really know better, but we all do stupid things sometimes. The other day i was turning a large piece of bar in the lathe. The chuck jaws were protruding well beyond the diameter of the chuck which was peventing me from fully closing the chuck guard. I was in low gear running only at about 100 RPM, but with lots of torque.

As I reached over the lathe to get something from a shelf, my Teeshirt slipped out of my waistband and was immediately caught up in the jaws of the chuck. This twisted me around and pulled me down towards the ground with the chuck jaws pounding against my back. I aimed a good hard blow at the mushroom switch which is my emergency stop button and all power was immediately disconnected. Unfortunately, in my panic I slammed my knee into the machine. The result of all this was a badly bruised back, a broken leg and 3 days in hospital.

However if I had to rely on getting to the mouse and finding the Estop icon on the screen, it could have been a lot worse. Experienced machinists will know that you should not wear loose clothing whilst operating machinery. It is also not a good idea to reach over moving machinery, but above all you need a reliable way of stopping the machine quickly in the avent of an emergency.

I hope my experiance may be of benefit to newcommers to machining and perhaps just a reminder to everyone else.

Neptune

Offline Sam

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Re: Safety First
« Reply #1 on: July 07, 2011, 04:50:29 PM »
Wow  :o  Glad you made it out alive. It coulda been a whooooole lot worse. Actually being able to focus your mind into hitting the E-stop in a time of panic is no easy feat. If the chuck had been spinning faster it prolly woulda got ya regardless. Hopefully the company won't try to pin it all on you, not following safety protocol, and fire you or "downsize" or some other nonsense to get rid of ya.
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preventing me from fully closing the chuck guard
What's this "guard" you speak of?   >:D All of ours are removed. Hope I never pay for it with injury.
Thanks for sharing your experiences.
"CONFIDENCE: it's the feeling you experience before you fully understand the situation."

Offline budman68

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Re: Safety First
« Reply #2 on: July 08, 2011, 04:59:45 AM »
Glad you're ok!

This is the reason the word safety exists, and thanks for sobering some of us up a bit-

Dave
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Offline Jeff_Birt

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Re: Safety First
« Reply #3 on: July 10, 2011, 07:45:31 AM »
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Having just read a recent post about operating Estop button with mouse, I thought I would add my advice to that of many others who say that you really must have a hard wired emergency stop switch which is easily accessible, cuts off all power to spindle and drives and is independent of software.

Ahmen!

I'm glad to hear that you are doing OK Neptune and thank you very much for sharing your story. Many hobbyist and even folks in industry tend to discount the value of having a proper EStop system, I even see commercially made machines that are improperly wired from the factory in this regard. There was a young girl killed at a US university earlier this year when a lathe got a hold of her hair and there was no-one else around in that area of the shop to help her out. What a tragedy.

These types of accidents to not happen frequently but the fact is they are avoidable. Having a guard over the chuck serves two purposes, one is to help keep one from starting the lathe with the chuck key still in the chuck (and we have seen/done that), the second is to help keep body parts out of the chuck. My first thought for the case presented here is, "Why have a shelf behind the lathe?" I admit I have some things hanging on a peg board behind my older Clausing lathe, it makes me reconsider an earlier idea of moving it to a position angled from the wall so there is nothing behind it. My initial idea in moving it was to better organize the shop and make it easier to clean behind the lathe but now I can see the value in removing the temptation to reach over the lathe when it is in operation.

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What's this "guard" you speak of?    All of ours are removed. Hope I never pay for it with injury.

Then you should quit and/or turn them into OSHA and find a different job. I am NOT one to want to run to big brother government but it really ticks me off to see a business treat their employees as disposable. If an individual wants to remove safety guards form their own personal equipment then that is their own decision. A business has a responsibility to take reasonable steps to keep their employees safe, removing guards shows a disregard for others.
Happy machining , Jeff Birt
 

Offline Chaoticone

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Re: Safety First
« Reply #4 on: July 10, 2011, 08:23:25 AM »
Neptune, so glad your still with us and hate you had to go through this.  Thanks for shareing.  All of us need to hear about these things when they happen.  They are sobering reminders. 

Get well soon,
Brett
;D If you could see the things I have in my head, you would be laughing too. ;D

My guard dog is not what you need to worry about!
Re: Safety First
« Reply #5 on: July 10, 2011, 10:19:38 AM »
Thanks for all your comments.

Jeff, it is a bad idea to have a shelf behind the lathe. It's just that in a home workshop many of us are limited for space and there is a temptation to use every available bit of wall, but it has made me think about re-arranging things.

Sam makes a good point.

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Actually being able to focus your mind into hitting the E-stop in a time of panic is no easy feat.

When these things happen, your brain seems to work in slow motion. You are thinking, how do I stop this thing - oh yeah, hit the big red switch. You don't want to be thinking, where did I put the mouse when it was in the way just now, why is the mouse pad cluttered up with tools so that I can't move it, why can't I see the monitor from where I am trapped or why has Mach chosen this moment to freeze, etc, etc.

Seconds really count in such circumstances.

Thanks again
Neptune

Offline Sam

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Re: Safety First
« Reply #6 on: July 10, 2011, 01:54:54 PM »
Jeff, by no means are they removed and thrown away. Any time if I feel like using them, they are right there next to the machines. 100% personal preference. You'd be hard pressed to go into a job shop, around here, anyhow, and find 1/10th the safety equipment, and operating rules that a larger industrial place has. Not trying to sway from the original thread here, but...personally I feel like SOME of the "safety" measures put in place are just as much of an added hazard, as to what they really offer in protection. Take vehicle air bags for instance. They are a great thing and save many lives, but lets say that airbags were not enclosed, but rather partially inflated. They are put in place to protect you, but the added hazard of working around them, actually creates or contributes to other hazards. This very subject (safety guards) has been preached many times in other forums, especially in woodworking forums. Wars have been fought about it, and people have been killed. Kinda like religion or politics. What I'm concerned most about on a lathe is the stringer chips. Get a pile of those in the pan, and it don't take but but a split second for a stringer to pick them back out of the pan, in tornado fashion. Only thing a guard would have done in that particular case, is add to the shrapnel flying around. To each his own, I guess. Nothing is a guarantee, whatever the choice. Do whatever is safest for you.

About the mind focus...I ALWAYS have my hand on the e-stop when I run a part for the first time on the CNC lathe, and turn the feed rate down. Things have gone wrong before, and even then, when I'm prepared for it, my mind still thinks "oh crap, what do I do!" for a split second, and I have to refocus on pressing that button. Strange.

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When these things happen, your brain seems to work in slow motion.
A guy at a shop next door to us was using a large hand held disk grinder. He must have been using it in an awkward position or something, but it kicked back, and gashed the side of his neck open. I spoke with him later, and he said that the first thing he thought was "I'm dead. I'm going to bleed out before I can get to the hospital."
     'I had come to terms with that, and that's just the way it was. There's nothing I could do about it.'
"Then I thought, How are my wife and kid going to make it without me. I don't have enough life insurance to secure their future."
"You'd be amazed at the things that you think about when something like that happens. It's not the bills that are coming due, or new tires for the car, but all the important things in life that really matter."

It was sobering to hear him tell it, and see the skin graft battle scar. Sends shivers down my spine every time I see the guy now.
« Last Edit: July 10, 2011, 02:05:58 PM by Sam »
"CONFIDENCE: it's the feeling you experience before you fully understand the situation."