Thread: chuck gards on lathes

Originally Posted by Steamwhisperer

I found it odd that when I bought my AL340D brand new that it was physically impossible to fit the faceplate with the chuck guard in place. I had to remove the mounting bracket as that was the part that was fouling. I haven't got around to refitting it yet. I thought there might have been clearance holes to facilitate moving the mounting bracket slightly and leaving enough room between the bracket and faceplate but nope. So I guess it will have to stay off. Crazy they would fit a guard you can't use.

Phil

That is an interesting situation, with a brand new machine. My new lathe, as I am sure I have mentioned before had a chuck guard fitted not long before it was condemmed for not having a feed screw cover. I have been cleaning up various bits ready for the wet months to prevent more rust forming than was there when I got it. The face plate is 450mm diam. It had a bit of surface rust on it but also what appeared to be the paper used to protect flat surfaces. I don't thin k it has ever been used since new in 1997. I doubt it would fit with the guard in place.

My thought was to leave the guard in place but not switching the lathe and try to make it easily removable altogether. Like the guard on my mill I have not decided yet but I am very close with that item.

Dean

This is a friend of a friend story but a wire product manufacturer in Brisbane, packed up all his equipment and shipped it overseas because of guarding rules.... He was told to place guard over x part of machine, he explained a guard there would foul the machine and it would no longer operate.... They said they did not care, put a guard there...

So now he still makes product, and we use it in Australia, but instead of being made here, it comes in, in shipping containers, the risk to human health is still the same, just that risk no longer applies to Australian people... That must make it OK..

Although there were probably other factors as well in his decision to move off shore and the OHS was the tipping point.

Originally Posted by .RC.

This is a friend of a friend story but a wire product manufacturer in Brisbane, packed up all his equipment and shipped it overseas because of guarding rules.... He was told to place guard over x part of machine, he explained a guard there would foul the machine and it would no longer operate.... They said they did not care, put a guard there...

So now he still makes product, and we use it in Australia, but instead of being made here, it comes in, in shipping containers, the risk to human health is still the same, just that risk no longer applies to Australian people... That must make it OK..

Although there were probably other factors as well in his decision to move off shore and the OHS was the tipping point.

Sounds like a story a mate told me about his gun securing issues many years ago. He was told he had to secure his rifle with a padlock attached to the trigger guard. This guard was plastic and could be broken very easily. Did not matter. Rules are rules.

Dean

Originally Posted by Michael G

My copy of the relevant Australian Standard is years old and I haven't read it cover to cover recently, but my understanding was that production equipment had to be guarded when ever possible to avoid (presumably inexperienced or untrained) operators being able to come into contact with parts that may injure, whether that be rotating or crushing or whatever. From memory there was an exception granted for jobbing machines - because of the varied nature of the work done on them operators were excused from having extensive guarding. For example, if you think about a job mounted on a faceplate, a chuck guard soon becomes impractical. The assumption was also made that the machines were operated by properly trained people who understood the dangers present.
There is also the risk mitigation school of thought that says dangers are to be removed/ guarded against etc whenever the analysis of consequence and likelihood suggest there may be an issue. From a manufacturer's point of view chuck guards are cheap, well known and can be fitted. Therefore to guard themselves against accusations of selling "unsafe" products, they fit them. (I don't like seeing that word - "unsafe" - it is usually brandished by people who have no idea about risk or reality). You are not allowed to mention cost and safety together, but the guiding principle in risk reduction is ALARP - "As Low As Reasonably Practical", so unreasonable expense is a defence for not having full guarding, although other measures would be required to mitigate the risk present (training for example).
As a result your lathe probably has a chuck guard because it could be used in a production environment, and guards are not expensive or difficult to fit.
I bought a drill press for work the other day which also had a chuck guard. The really weird thing was that it was so big that it meant that you couldn't actually use the drill properly. I can't of course tell our fitters to modify safety equipment so that it can be negated but I can guess one of the first things that will 'break' on that drill press.

Michael

hi Michael
how are you.
what aust standard is that?
thanks aaron

Hi All,
There are many Standards for Machine Safety, the main one being AS4024.1-2006 Safety of Machinery. It is in 26 Parts and takes a Risk and Hazard approach to Safety. It was based on the European Standards and condensedinto one folder.
It works on looking at the Hazard and how a person will interface with that Hazard and recommends methods to reduce the Risk, a relative cheap method is Guarding as it works on separating the Hazard from the person and in the case of Lathes where the Guard is fitted at the Chuck and isusually a Hinged Guard it is interlocked into the Machines Control System via a Switch which usually is a Limit Switch.
This method is used by a lot of Machinery Manufacturers as seen on the Lathes, Drills and Mills from suppliers like H&F, it if you lookat it is just a bolt-on after thought to give them some compliance to Australian Regulations.
In the case of Machine Tools like Lathes, Mills and Drills the basic versions are manually operated so these guarding methods mentioned are deemed to be appropriate as the operator is in control of the machining but in the case of automated Machine Tools like CNC the operator is not in full control of the Machine so more complex Guards are fitted and have more complex Safety Control Systems.
A lot of the Guards that are on Lathes are not well thoughtout and in some operations are in the way or dangerous hence people overriding them or just removing them. In a home workshop you are not subjected to the same requirements as in Industry so are free to make any modifications you want but in Industry you need to comply to the relevant State Act and Regulation that requires some form of guarding.
There are no easy answers so we will see different forms of guarding the good and the bad.
Keith_W

G'day Aaron
The standard that I have is AS4024.1 - 1996, so an earlier version of the one that Keith has referred to. It is also risk based but I would have to check it against the latest version to see how much it has changed.
I can't (with a casual flick through) see the bit I thought existed that suggested a less extensive guarding was needed in jobbing machines, so that could well have been from an earlier standard. AS4024 was derived from an ISO standard in 1992, so I am possibly thinking of something from before then. Using a risk based approach a case could be made different safeguards on machines that are used for jobbing by experienced people.

All that aside, I was trained to take the view that safety is the responsibility of everyone and the primary defence against an accident should be the person behaving in a safe manner rather than abdicating this responsibility and (for example) relying on guarding to protect them. I deplore the idea that extensive guarding or interlocks are needed just so people can behave like idiots without taking personal responsibility. Guarding is in place on my equipment but just like a seat belt it is one of those things that I hope is never necessary that I test.

Michael

hi ill have to read this all again. thanks for the replys

Originally Posted by Keith_W

Hi All,
.........
In a home workshop you are not subjected to the same requirements as in Industry so are free to make any modifications you want but in Industry you need to comply to the relevant State Act and Regulation that requires some form of guarding.
There are no easy answers so we will see different forms of guarding the good and the bad.
Keith_W

Keith, you may make any modifications you see fit in a home workshop, however if the worst happens & if the regulators prove you are conducting an "undertaking" they may deem you must comply and may have grounds to prosecute. Unlikely but possible. It starts getting very muddy when hobbyists sell products or "teach" others - does that meet the criteria as an "undertaking."

This is a very intersting thread btw. Particularly the comments about training & experience and using jobbing lathes. My interest is in woodturning & safety which has some strong parallels with similar hazards & risk but with the additional hazards & risks of hand held tools and close proximity to rotating workpieces etc.

Originally Posted by Michael G

G'day Aaron
....... I deplore the idea that extensive guarding or interlocks are needed just so people can behave like idiots without taking personal responsibility. Guarding is in place on my equipment but just like a seat belt it is one of those things that I hope is never necessary that I test.

Michael

Training......??? Every one is cutting corners & relying upon on the job training. Unfortunately that is why guarding is there to protect people from themselves; & bosses & insurers from their workers plus the occasional act of willful injury.

I would like to add some more of my observations on OHS inparticular about Machine Guarding and welcome any comment on them.
I am looking at an Employer who has a Business Undertaking, the new term that the regulators are using as found in the current OHS Acts andRegulations. Each State has taken the Federal Governments Model OHS Act and Regulations and are enacting it in their State with some modifications but in essence following the main principals. In the Regulations you will find a section on General Risk and Workplace Management,I include an excerpt from the NSW Regulation;

“Chapter 3 General risk andworkplace management
Part 3.1 Managing risks tohealth and safety
32 Application of Part 3.1
33 Specific requirements must becomplied with
34 Duty to identify hazards
35 Managing risks to health andsafety
36 Hierarchy of control measures
37 Maintenance of controlmeasures
38 Review of control measures“

In the Part 36 they use the Hierarchy of Controls to be applied by the duty holder (Employer) when the Risks cannot be eliminated,excerpt from NSW Regulation;

“36 Hierarchy of control measures
(1) Thisclause applies if it is not reasonably practicable for a duty holder toeliminate risks to health and safety.
(2) Aduty holder, in minimising risks to health and safety, must implement riskcontrol measures in accordance with this clause.
(3) The duty holder must minimise risks, so far asis reasonably practicable, by doing 1 or more of the following:
(a) Substituting (wholly or partly) the hazardgiving rise to the risk with something that gives rise to a lesser risk,
(b)isolating the hazard from any person exposed to it,
(c)implementing engineering controls.
(4) If arisk then remains, the duty holder must minimise the remaining risk, so far asis reasonably practicable, by implementing administrative controls.
(5) If arisk then remains, the duty holder must minimise the remaining risk, so far asis reasonably practicable, by ensuring the provision and use of suitablepersonal protective equipment.
Note. A combination of the controlsset out in this clause may be used to minimise risks, so far as is reasonablypracticable, if a single control is not sufficient for the purpose.”

My observations of this is that if you cannot eliminate the Hazard and in this Thread we are talking about Lathes measures like paragraph 3 b & c are used, e.g. Guarding and the Interlocking of that Guarding to meet the Engineering Controls and paragraph 4 Administrative Controls e.g. things like Work Method Statements, Training etc.

As has been discussed Guarding offers an easy solution in achieving this and is why you see things like Chuck Guards, Covers over the Screw, Enclosed Gear Trains etc. For the Engineering Controls you see things like Micro Switches interlocked on the Guards into the Lathes Control,Emergency Stops fitted or Foot Stops/Brakes fitted etc.

In most of the Regulations at they offer Australian Standards as guide lines to achieve these and the current StandardAS4024.1-2006 is listed as a guide for Machine Safety where there is not a specific Standard for the Machine or a Code of Practice.
I attach a Word Document that lists the parts of AS4024.1-2006 and gives an outline of the different parts.

This Standard is what is commonly used by theMachine Tool Manufacturers and is from a number of European Standards. In Europe they have been updating their Standards and there are two new Standards that would apply being EN-ISO 13849-1 IEC 602061 which are being used and intime our Australian Standards will adopt into AS 4024.1.
As I said before these are my observations and throw this into the mix.

Keith_W

thanks again every one. i should put it out there the way i see it..
i think the shiny bums at work are using the no chuck guard approach to get rid of the lathes and dont really understand the value of the machines.
they feel they are only used for foreigners and this isn't true.
aaron

Originally Posted by azzrock

thanks again every one. i should put it out there the way i see it..
i think the shiny bums at work are using the no chuck guard approach to get rid of the lathes and dont really understand the value of the machines.
they feel they are only used for foreigners and this isn't true.
aaron

What about guards on the feed screws etc. My work, as I have already said fitted a chuck guard but it was the feed screw problem that condemmed the lathe as it was too hard to remedy. This is over the border in SA tho.

We have had a problem for years with cleaning silicon bungs used in the barrels. One method suggested was to use a cement mixer, toss them in as they are freed up and clean them on a daily basis. Empty every morning after a rinse. We kept being told about the guarding problem which I could not understand. They are sold to the public they have to meet safety standards. What is the problem. When I picked up my mill last year from Paramount Browns I had a look. They had about 5 of differing sizes outside on display. I instantly saw the problem. The guard over the drive gear had such a large gap that even the largest hands could get easily get thru and caught in the gears. Obviously too expensive to fit secure guarding and this is one situation where it would be of positive benefit.

Dean

Yesterday I used the big Nuttall lathe at work to turn a 100 mm diam steel rod. This lathe has recently been fitted with a guard and seeing as the lathe can take big chucks so it has to be a big guard and I have to say I found the guard quite useful and not at all intrusive especially as the power interlock has been disable. The first thing I noticed was the guard does reduce the temptation to stick your hand in there to clear balls of swarf but the best thing about it was I could run the coolant at a reasonable flow and chuck at top speed and the guard caught most of the coolant spinning off the chuck. I reckon I might have to have a crack at making one for the Hercus.

Seems there maybe 2 things a bit amiss in that scenario,defeats the purpose slightly if the interlock has been by passed,not sure how workcover/authorities would look at that.

The other with the training and work habits of the operator being tempted to remove swarf by hand.