key in chuck safety device

When I first bought my lathe, I've made this device afraid of letting the key in chuck.

https://youtu.be/pzLVN8HWLLY

As a side effect, it becomes very convenient when I finish a part I just grab the key (to remove part) and lathe stop.

Hi Cascao
Nice original thinking
Key left in chuck is not something I ever do even for a few seconds, however for those who are worried about this issue yours is the best fail safe solution I have seen and could become a commercial feature. It certainly avoids the infuriating self ejecting coil spring on the key.
Regards
Olderdan

I've seen the equivalent setup used on drill presses. As Olderdan points out, it's the least infuriating solution.

The only problem with it is the fact that it's easily defeated. Simply shove a screwdriver or similar in there and the chuck key is free. Not a problem in a one man shop but in a multiuser setup it is a threat.

There are (overly complex) ways to avoid the screwdriver shortcut. For example, mount several switches to contact the wrench at body and tip. These switches would, in effect, read the shape of the wrench and only complete the circuit if all were operated. Defeating something like this would require turning an accurate facsimile of the real wrench and inserting it - something the average bodger isn't likely to do.

As I said, way too complex to be practical.

I see nothing wrong with your idea of disconnecting the power when the key is removed from its holder. I would have an issue with the idea that the spindle appears top be on lock down when the key is removed. I find it best to rotate the chuck when tightening stock in a 3 jaw to check concentricy with a dial indicator. this is a must when using a 4 jaw
The first thing I would have to do if any lathe of mine had an electro magnetic brake on it would be to install a foot switch which releases the brake but does not allow for motor start up That way the the spindle could be rotated with the key out of the holder but the motor could not be started

What happened to just being careful, nothing can override that.

I like the idea, as long as spindle isn't locked from rotating, per Frank S's observation.

Being careful is a conscious act of knowledge; and at least visualization of hazards. 'We' have it. We even converse about it...
It comes with education:soapbox:, mentoring:headshake:, sometimes experience :smash:

Ornate safety mechanisms, boilerplate disclaimers, and numerous hoops to navigate, not to mention endless liability suits; cater 2-3 generations who didn't grow up in an environment learning general mechanical practices by steps. Many have no genuine exposure at all, neither orbital or direct.
They see a video, go out to buy, plug and play. Fine for some endeavors, not OK for others.
Instant gratification is not an appropriate learning curve.

My 12" X 36" lathe from the Far East has a "chuck guard" which has a pivot shaft connected to an electrical cut off switch. If the guard is raised while the machine is running the machine turns off, the machine can't be restarted until the guard is lowered and the guard cannot be lowered if the chuck key is in the chuck.
When I first started operating this machine I wasn't that keen on this feature, but have become used to it and subconsciously use it as a pseudo on/off switch.

Great idea cascao

Own up chaps, has anyone here launched a chuck key yet.
thankfully not, but i did launch a thin wall pipe that i was supposed to be turning into a jewellery box at school in my very first lesson. Initially i was stunned then had uncontrollable fits of laughter. The only thing to hit me was the back of Mr Clarke's hand. I know of two people who have lost fingers in Lathe accidents, i'm pleased to say i maintain a healthy fear of machines, you don't see fighter pilots getting complacent, putting there feet up and having a chat. FEAR is your friend.

I agree with toolmaker, its better to remove the idiots from the equation. The UK is hell bent on employing graduates with engineering degrees now, even for menial roles. University's don't teach practical skills and craftsmen have all but gone. Screaming out for skilled people to fill to fill the void has proved fruitless as many skilled people don't want to work for the minimum wage - cant afford to live on it for starters. Where rents for housing are now 60% of your salary. In this nanny state of over zealous health and safety i can only see the skills problem getting worse and a few thickets being consumed by machines when they bugger up.
I have found the safest place for my chuck key is in the tray or when its not in use back in the tool rack on the wall. I have a friend David Rhodes who has a machine shop here in Carlisle, i was gob smacked to see him leave his chuck key sticking out of the chuck, he used to work in the weaving mills as a machinist and should know better, he will have started as an apprentice and worked his way up.
Oh the days before health and safety when natural wastage ruled the day, idiots just killed themselves leaving less idiots on the planet.

When i was say at New Years looking back at what id achieved and where i wanted to aim in 2018, i realised that in life i have now reached a point where i have put more things together than what i have taken apart. Yes i started off as a stupid boy taking everything apart, i'm pleased to say i recovered. My aim for 2018 is to keep banging on about the skills shortage in the UK, i should probably get over it but this would mean a career change. Unfortunately as they say. " Hi my name is Jason and i'm an Engineer" ( applause ) now all i need is detox. I've heard the only cure is to have your spine surgically removed, damned if you do get out of engineering damned if you don't.

Growing up in an environment at school and when working if you did not practice safe work habits you would be kicked, wacked around the head or have something heavy thrown at you if you stuffed up I just about have a panic attack if I looking at a photo of a key sitting in a chuck that does not have a hand attached.
Nice mod Cascao, no matter how hard we try there may always be that day so everything we can do to 'make safe' without being stupid is good.

MeJasonT, I hate to be the bearer of bad news but your lament is a global one. What makes things worse is that those younger people who have a genuine longing to learn are stifled by regulation and all the old hands are retired, retiring or dead. I know that everything new I learn makes me realise how little I know and despite my love of reading some things can;t be learnt from a book, app or You Tube, common sense being first and foremost.

<!-- BEGIN /var/www/html/homemadetools/protected/modules/zeus/views/tool/postUpdate.php -->
Thanks Cascao! We've added your Lathe Cutoff Switch to our Safety category,
as well as to your builder page: Cascao's Homemade Tools. Your receipt:

<div id="blocks"> <div class="block b1 pngfix"> <div class="bimg"> <div> <a href="http://www.homemadetools.net/homemade-lathe-cutoff-switch"> <img src="/uploads/208993/homemade-lathe-cutoff-switch.jpeg"/> </a> </div> </div> <div class="head pngfix"></div> <div class="left pngfix"></div> <div class="right pngfix"></div> <div class="blockover b1 pngfix"> <div class="title"> <a href="http://www.homemadetools.net/homemade-lathe-cutoff-switch">Lathe Cutoff Switch</a> <span> by <a href="http://www.homemadetools.net/builder/Cascao">Cascao</a></span> </div> <div class="tags">tags: <a href='http://www.homemadetools.net/tag/lathe'>lathe</a>, <a href='http://www.homemadetools.net/tag/switch'>switch</a> </div> </div> </div> </div>
<!-- END /var/www/html/homemadetools/protected/modules/zeus/views/tool/postUpdate.php -->

No matter what you do YA just faint fix stupid . Good way to start but they would disable it somehow.

I see there is a happy little band following this thread, about Cascao's chuck key.
You'll all laugh at this, but I have instances where the key needs use often. Wearing shop apron, or pants and tucked-in shirt, I find slipping the keys shank in the belt awfully convenient.
Otherwise, my rule of thumb is if the key's in the chuck, one hand is on it. On some lathes, keys are a good 'handle' jogging gear trains when shifting speeds. That's part of the belt & key thing, it is in my right hand.

Key in the right hand? Only us old guys who have had to jog a 20" or larger chuck a few degrees back and forth to be able to get the gears to change Don't remember ever tucking one in my belt but have dropped it in my apron pocket on occasion rip more pockets off that way

I think that is a brilliant idea. Simple and effective. While I have never made the mistake of leaving the key in the chuck (I put that down to a very good metal work teacher at high school) I have come close. It’s so tempting sometimes to just leave the key there for a second while I get something but I always stop myself and remove the key. Your idea will stop that and I hope you don’t mind me using it. I think I will call it a Cascao key :lol:. Thanks Stuart, Australia.

Early on I formed the habit of never leaving the key in the chuck - it always goes right back to its parking space even before I pull the work out of the chuck. It's a habit that hasn't failed me so far and in fact it's even a bit of a reminder to stay alert and not be doing anything while on autopilot.

I do tie wrap my other tools' chuck keys to the plug end of their power cords so that I'm forced to disconnect power before putting a key in any chuck.

Still got ten and no stubbys (knock on wood) but I have had a hole cutter bar and cutting tool go flying close by me at not quite mach 1.