Lathe chuck guards – how many folk use them?

[RedsetterParticipant @redsetter]

Posted by Robin Graham on 05/11/2019 00:41:45:

Thanks for comments about leaving the chuck key in. For me personally I don't think I'm going to get bitten by this because the process of removing the key after tightening has become instinctive (where I put afterwards is another matter – definitely STM issues there!). I guess that it may be more problematic in an industrial environment. But I like to try and understand these things.

Robin

Famous last words!

If you instinctively remove the key after tightening, why do you then leave it in when the chuck is empty?

One day you will forget, and start the lathe with the chuck empty and the key in place.

I'm sorry mate, but you will get bitten.

[not done it yetParticipant @notdoneityet]

Well said, Redsetter. Having a mishap requires only one mistake if the key is left in as a ‘routine’; it requires two mistakes if one resolutely never ever leave the chuck key in. Once that initial mistake (of leaving it in) has been made ( and hopefully noted before the second mistake) it would reinforce the fact that anyone can forget their routine. We are not infallible. If we were, we would never have any dud workpieces in the scrap bin!

[DanielParticipant @daniel]

+ 1 to the above.

The only time my chuck key is in the chuck, is when it is actaully being used.

Rigidly, after that it is replaced into it's hole on the rear splash guard.

This deliberately forced habit has become a reflex, not unlike wearing a car seatbelt.

ATB,

Daniel

[Michael GilliganParticipant @michaelgilligan61133]

Just a thought …

Perhaps we should follow the aerospace example: **LINK**

https://en.wikipedia.org/wiki/Remove_before_flight

provided, of course, that there is somewhere to safely stow the flagged key after removal !!

MichaelG.

[not done it yetParticipant @notdoneityet]

Posted by Michael Gilligan on 05/11/2019 09:56:47:

Just a thought …

Perhaps we should follow the aerospace example: **LINK**

https://en.wikipedia.org/wiki/Remove_before_flight

provided, of course, that there is somewhere to safely stow the flagged key after removal !!

MichaelG.

A bit OTT? We are likely only to kill or maim ourselves, not an aerospace risk which could injure/kill lots of people.

Adequate in this case would be a limit switch, in the normal parking spot (for the key), in series with any safety interlocks (emergency stop circuit)?.  That, I think, would suffice – if really deemed necessary.

As I said earlier, my lathe has soft start, so even if I left the key in the chuck, I doubt it would become a particularly dangerous projectile as all my VDFs are programmed for a fairly sedate ramping of speed. I am not in a production environment. It is my hobby and as such a leisure activity (most of the time).  More likely to damage my lathe than me?

Edited By not done it yet on 05/11/2019 10:16:59

[JuddyParticipant @juddy]

The precautions you take should be in proportion the risk they represent, for example if the chuck key is left in when a lathe is started, this could in extreme but foreseeable circumstances kill, certainly if it hit you full in the face. Then the precaution put in place to prevent this happening should be robust and infallible as possible, hence the interlocked chuck guard, sprung key etc. Remove these features and the risk increases. As discussed within this topic, the risk may be small for a person of experience that keeps to a routine regarding key removal, but the risk is still there and the consequences real.

I use a sprung chuck key, which I find a pain to use, but I know I’m not perfect and I do make mistakes even if rarely so I keep the spring in place. The chuck guard on my old Boxford is not interlocked but it is still on the machine and does get used when I deem there is a risk of flying swarf, coolant or I’m not confident that I can work within what I deem an acceptable risk to me or any family that come into the workshop (bringing tea hopefully).

This is more about levels of personal risk acceptance than whether the guard can be taken off or not, just be aware that you are not just accepting the risk but the consequences of it being realized if it goes wrong. Once it has gone wrong how serious the accident is up to the Gods.

[Michael GilliganParticipant @michaelgilligan61133]

Posted by not done it yet on 05/11/2019 10:13:58:

Posted by Michael Gilligan on 05/11/2019 09:56:47:

Just a thought …

Perhaps we should follow the aerospace example: **LINK**

https://en.wikipedia.org/wiki/Remove_before_flight

provided, of course, that there is somewhere to safely stow the flagged key after removal !!

MichaelG.

A bit OTT? We are likely only to kill or maim ourselves, not an aerospace risk which could injure/kill lots of people.

Adequate in this case would be a limit switch, in the normal parking spot (for the key), in series with any safety interlocks (emergency stop circuit)?. That, I think, would suffice – if really deemed necessary.

[…]

.

 … A cost comparison between these two solutions might inform the decision as to which one is OTT **LINK**

MichaelG.

Edited By Michael Gilligan on 05/11/2019 10:50:00

[Brian GParticipant @briang]

I like the idea of a limit switch to enforce a fixed location for the chuck key. Not so much for safety (I have an interlocked chuck guard) but to save my regular 5 minute searches for it. I suspect that my son would say that a silhouette board or french-fitted drawer with switches for my micrometers, calipers, toolholders, scriber, rules etc. might be even better.

Brian

[Mick B1Participant @mickb1]

I think one should consider risk in proportion to its possible consequences. I'm no more perfect than anyone, and on the occasions where I've switched on with the key in place on my ME-sized lathes – I do it perhaps once a year or so – I've suffered no more than a non-bruising clout on the ribs, plus an unpleasant surprise at myself. Maybe because I tend to use HSS and slower speeds than some.

I do remember from my days in industry when a key flew from the chuck of a big Binns & Berry I was running to make cable reel end flanges for the Coal Board. It stove a deep gash in a chipboard partition several yards away. 'Twasn't me that started it, it was the maintenance man, who was sorting out the rapid traverse on its heavy saddle – but it might have been me that left the key there. No real harm done, but it showed what could've been.

So if you develop habits on your size machines, remember they may need different emphases elsewhere.

[David James JennerParticipant @davidjamesjenner99025]

My Mini lathe came with a interlocked chuck cover, a shield bolted to the carriage and a spring on the chuck key.

I removed them all as I found that the already restricted access was made worse.

In my defence, I was apprentice trained (1973, 74 with the CEGB ) and the one thing we never did was to leave a key in any chuck, be it a lathe chuck or a drill/mill chuck. More out of fear of the instructors seeing it and the "telling off" in no uncertain terms in front of the entire group than the physical injury.

In fact its best not to leave any handle or key in any machine that is not needed for the immediate operation as these can snag.

The other saying that stuck was not to put your finger where you would not put your "*****"!

Dave

[Martin KyteParticipant @martinkyte99762]

The key to safety is good practice and guards, interlocks and all the rest are there to either engender good practice or in extreme cases to force it.

In single operator workshops I guess we have to consider the things that cause us personally the most dificulty in staying safe. I have no problem consistantly removing chuck keys but it clearly worries some so it would make sense for them to have some kind of mechanical reminder system such as key springs or guards with interlocks. The important thing is to understand you own peculiarities and act accordingly. A habit of automatically thinking about potential pitfalls as they are created helps. How many of us think if I don't move that I will trip over it etc.

The other thing that occurs to me is what happens when we cease to be the only user when a grandchild has become old enough to come and have a go. I am sure my workshop would need some serious thought to remove potential for harm for a small person who has no previous awareness of the hazards. Just as the level of guarding appropriate to a factory floor may be over the top when applied to a tool room, what we would consider 'safe' may be inadequate for a youngster.

I don't have a guard fitted to the Myford, but I will if my young great nephews come and have a go.

regards Martin

[Mick B1Participant @mickb1]

Posted by Martin Kyte on 05/11/2019 13:28:40:

…what we would consider 'safe' may be inadequate for a youngster.

I don't have a guard fitted to the Myford, but I will if my young great nephews come and have a go.

regards Martin

I've had one of my granddaughters making a pen body on my Warco when she was 7.

'Tain't the guard you have to worry about – it's their distraction of the thousand other incomprehensible (to them) things in yer workshop. You have to watch 'em like a hawk to see what they might pick up.

She made the pen fine, and without incident, but watching and teaching for an hour or two – whilst it was fun – was no trivial piece of work …

[old martParticipant @oldmart]

I noticed that a good many people removed their chuck guard because it was badly designed, or just got in the way. Nobody seemed to think of designing and fitting an improved one.

This thread makes me think of parents taking their kids for a bike ride and dutifully fitting cycling helmets to their kids heads while going bareheaded themselves.

[Mick B1Participant @mickb1]

Posted by old mart on 06/11/2019 21:08:55:

I noticed that a good many people removed their chuck guard because it was badly designed, or just got in the way. Nobody seemed to think of designing and fitting an improved one.

…

I don't think that's gonna happen. Anything that works as a guard must also interfere with close examination of what's going on at the toolface. Anything transparent just gets crudded up in seconds, even when cutting dry.

[ChrisHParticipant @chrish]

I've been using lathes on and off for over 50 years, but all the lathes I've used were old ones – my lathe at home is circa late 1960's early 1970's. No lathe I used ever had a chuck guard fitted, and I've lived happily without one, most of the time. The only time I would like one is when I'm using coolant, so save on the mess going all over the shed floor, but otherwise I've never felt I needed one. I never stand in way of the swarf coming off, never leave a chuck key in the chuck – my initial training left a huge impression on me – and don't use two chuck keys on 4 jaw chucks.

But I see new lathe increasingly have a guard fitted in front of the toolpost as well, and for the life of me cannot understand why. In my shed that would be the first thing to be binned, but there is only me in my shed.

My mill/drill had an interlocked guard fitted in front of the quill action bit. That got binned very quickly, it interfered too much with setting up processes. Too often guards fitted to machines prevents the operator from seeing exactly what is going on too. A temporary screen gets put in place to stop chips and coolant getting flung all over the shed, but is quickly able to be removed out the way when required.

The important thing about guards is that they should be designed with the operation and maintenance of the machine in mind, so that their interference with the discharge of both tasks are minimised. This should be borne in mind when guarding is designed, but is very often not, guarding usually seemingly being designed by someone sitting at a desk far away from the shop floor, who has never had to operate or maintain (or even seen?) the machine they are designing guarding for; if they had, that guarding would have surely been very quickly redesigned!

If a guard interferes with the natural operation of a machine by its operator, human nature being what it is, then ways will be quickly found to circumvent the guard – and from experience in production industry, that is a proven. Guarding design is not the walk in the park designers often seem to think it is. Anyone can slap a secure 'screen' around a machine or tool, but can you then operate it?

Remember also, whether in your own shed on your own or in the firms shop, an accident only ever happens due to there being an unsafe action taken or unsafe condition existing. It therefore the responsibility of all of us to ensure unsafe conditions do not occur, neither do we take unsafe actions, however we operate our machines or provide for our own safety.

Have a nice day!

Chris

[Mike PooleParticipant @mikepoole82104]

Is a chuck guard a solution to a problem most people don’t have?

Mike

[Bob Brown 1Participant @bobbrown1]

When I purchased my Boxford AUD metric lathe (ex school) it came with interlocks on the chuck guard and gear cover so they both got removed as I like to apply a little oil to the gear train and the guard is just a pain.

[martin perman 1Participant @martinperman1]

Going slightly of track I've been using my local saw doctor a lot with them making me new blades for my powered saw, I aksed one day if they could show me their machines and was taken into the workshop where they had a mixture of old and new machines, one machine had a cover over it and I asked if it was still used and was told the the local health and safety office had insisted they fit guarding to it, the company said they couldnt because its design guarding would make it impossible to use so H & E banned them from using it. I think that we who have removed our guards have the same thoughts of the saw company, we use our machines knowing that we have to be careful and adjust our operations to cater for the lack of the guarding most of us use splash guarding which afford some safety but are easily removed to make setting easier. In industry I found that safety issues were addressed by putting physical blocks in the way as it was cheaper long term to do this than to train operators to properly use the machines, I say that knowing that mechanical blocks work and machine operators were cheap labour doing laborious repetative jobs.

Martin P

[SillyOldDufferModerator @sillyoldduffer]

Posted by Mike Poole on 07/11/2019 00:05:48:

Is a chuck guard a solution to a problem most people don’t have?

Mike

No, they're a simple way keeping flying oil, coolant, swarf, and broken bits of metal out of eyes!

Dave

[Perko7Participant @perko7]

Have not read all the replies to the OP, but enough to get a sense that there are 2 points of view.

My thought is that if it doesn't get in the way and does what it is intended i.e. stops you leaving the chuck key in, then why not leave it on? My Sieg C6 has one, and I'm glad it does. It doesn't stop lubricant or swarf flying about, it's not wide enough for that, just enough to cover the chuck body. It does make sure the chuck key is removed before I turn it on. It also makes a handy arm-rest when I need to use some emery cloth to polish something i've just turned. My Ideal lathe doesn't have one but I only run that at less than 500rpm and it is slow to speed up with slippage in the flat belt as the tension is applied so less potential damage if a chuck key is left in.

I have left a chuck key in the drill press chuck once. It has no guard. There is now a dent at face level on the side of a cabinet about 2m away, glad I wasn't standing in between them at the time.

[Robert Atkinson 2Participant @robertatkinson2]

Posted by ChrisH on 07/11/2019 00:05:13:

<BIG SNIP>

Remember also, whether in your own shed on your own or in the firms shop, an accident only ever happens due to there being an unsafe action taken or unsafe condition existing. It therefore the responsibility of all of us to ensure unsafe conditions do not occur, neither do we take unsafe actions, however we operate our machines or provide for our own safety.

Have a nice day!

Chris

The problem is that you say you have taken that first "Unsafe action" – removing the guard- in your workshop. You also seem to be advocating removing guards to others.
Assessing the suitability of guards should be part of the machine selection process. If it's not suitable get the vendor to fix it or look elsewhere.

Generally in industry it is insurance assessors that drive good behaviour regarding guards and the like. If they refuse cover you can't legally work (at least in the UK if you have employees or public access to your business) Note that even in the home workshop removing guards could have accident or life insurance implications if the worst happens and they find guards were removed. Not very likely but some insurance companies seem to be looking for any excuse to reduce a settlement or increase a premium.

Robert G8RPI.

[Robert Atkinson 2Participant @robertatkinson2]

Double post

Edited By Robert Atkinson 2 on 08/11/2019 12:45:39

[Mick B1Participant @mickb1]

Posted by Robert Atkinson 2 on 08/11/2019 12:45:05:

…

Assessing the suitability of guards should be part of the machine selection process. If it's not suitable get the vendor to fix it or look elsewhere.

…

Given that the presence of guards is often a lipservice provision by machine builders, and that we're supposed to be engineers capable of making up our own minds on a solution, I don't think any machine majoring primarily on its guards for USPs would likely make it into the bestsellers lists….

[old martParticipant @oldmart]

Dead right, Mick, machine builders have to supply their products with safety devices to satisfy the legislation, but there is nothing that says that the design has to be actually usable. Some of the worst designs are drilling machine chuck guards.

[Mick B1Participant @mickb1]

Posted by old mart on 08/11/2019 14:02:51:

Dead right, Mick, machine builders have to supply their products with safety devices to satisfy the legislation, but there is nothing that says that the design has to be actually usable. Some of the worst designs are drilling machine chuck guards.

Yes. Some seem to be intended to prevent anything cutting anything.

A cynic might say that the builders know full well that the first thing the buyer's gonna do is whip it off…

[Author]

Posts