Safety Light Curtains

I do not know the safety regulations in your country.

In some countries the fence must be bullet proof and with light curtains this is not possible

also beware that not all light curtains are created equal. some are not safety rated. and even some of the safety rated are not rated for applications using robot or press.

i have seen laser scanners that are very sensitive to dust and trip even if no dust cloud can be observed.

but light curtains are not relying on reflection, they use beam-through and are much more immune to particles in the air and lens contamination. the light curtain however requires proper alignment. i use SICK laser pointer tool for this, AR60

I've never seen a light screen tripped by weld slag spray or dust, but I have seen them tripped by birds flying through them, and sometimes by someone amusing themselves by tossing small bolts or nuts through them. And it's intuitively obvious that enough dust accumulating on the optics would eventually cause them to be tripped.

To deal with this, most light screens have some tolerance for extremely brief interruptions, and many have a "size" tolerance. But these tolerances have to be very small to still qualify for safety.

KImalia

Can you post the light curtain name and model ?

what safety regulations are required in your country?

@kimalia

What are the regulations in your country? It would be very kind to answer this question?

Quote from kimalia

I wonder, will the dust and chips set off the light curtains?

The breaking tip is the problem and not dust but 2m in my opinion is to short anyway

What are you actually asking for:

Distance is to short and flying bullets are deadly (I have seen a flying bullet and only a wall (steel and teflar saved our lives)

@ all:

the problem is not the distance between you and the robot (2m is too short; you may be within a time slot of 1 or 2 s (not much distince) but you may get hurt by the bullet (after beeing dead you could say the distance was ok, but the bullet killed me - did this help?)

In robotics safety is a very important issue: SAFETY FIRST

If you want an alibi I would suggest using a safety carbet; it could be still deadly (do you care about this?) but at least you had some thinking about it

let me type this very slowly : what...is...your...country...? what.. is ...your... light ..curtain... model?

each country has own standards and regulations. are we supposed to guess?

in Canada machine guarding directive is CSA Z432

robotic safety standard is CSA Z434

etc.

light curtains have different resolutions. spacing of beams is NOT the same. if you are using light curtain 2m away from hazard, chances are that is not going to be finger-safe model ...

Is your milling application just for fun (private use) or industrial use?

The regulations help to make the system more safe therefore you should care

The poster went with a Fence instead of light curtain so probably isn't concerned with light curtain regulations anymore. With Milling and chips flying, a light curtain may cause issues so not a bad decision.

The only safety issue that may be of concern is if you are using a cutting tool that could lose an insert and go flying through a wire fence opening. Depending on the tooling used and fence material used that may or may not be a concern. If that is a possibility then you should use solid fencing such as sheet metal instead of wire mesh to prevent a person on the outside from being struck.

Quote from kimalia

i do not care for the regulations in this case.

Anyone in this line of work who says something like that has proven they should not be trusted with automated equipment. Either they don't know what they're doing, or have a callous disregard for human life.

Most of the people you're interacting with in this thread have been in the field long enough to see people injured, or even killed, by the attitude you implied above. I've had two incidents where I came within millimeters of losing my life because someone else said "I don't care" and proceeded to act on that attitude. And if I'm honest, I can count 2-3 incidents where I was the one who got careless (due to fatigue or moving too quickly) and got lucky that no one got hurt as a result of my carelessness.

So, saying "I don't care" on this subject is a very good way to get experienced people to stop helping you on the forum. Because we don't want to help you in injuring or killing someone. And if you "don't care," you will injure or kill someone, eventually. It's hard enough to avoid even when you follow every safety rule obsessively.

And before you try to say we're taking an offhand comment too seriously: this is a topic where we cannot afford to have a sense of humor. If someone says "I don't care," we have to take it seriously, barring explicit clarification. And anyone in the forum who enables this kind of attitude is a candidate for banning.

TLDR: there are damned good reasons we take this subject seriously. Respect that or GTFO.

EDIT: I probably came across as rather intemperate, above. There's a reason for that. I literally just left an entire production line that was, apparently, designed&built by a Chinese company, to apparently no safety standard, and shipped to be installed and put into production in a North American plant.

There was no safety. At all. The robots had their built-in pendant E-Stops, but those only stopped that robot -- nothing else. There was no lock on the gate, not even a latch -- anyone could walk into the cell, at any time, and everything would keep running. There was no place to lock out air, electrical mains, or other energy sources -- killing the 480V mains to one robot required going to the plant level main electrical box and turning off the breakers for an entire zone of the building. Every safety interlock on the robot was hot-wired. There was no "software" safety -- the PLCs were non-safety rated, there was no CIP-Safe on the Ethernet/IP network, and no safety options installed in the robot (hence, no safety-rated way to ensure the robot couldn't punch right through the fence if someone programmed it incorrectly). Adding even minimal safety to meet RIA 15.06 will require massive amounts of new hardware, and re-wiring everything.

In the two weeks this line had been powered up for installation, they've already had two "near miss" events where someone teaching one robot was nearly hit by an adjoining robot that someone else had put into automatic and accidentally started.

I've seen some pretty damn serious safety oversights in the past, but this was pure, high-octane nightmare fuel. I did a massive write-up, helped add some makeshift interim safeties using the non-safe I/O, and made it clear I would not hesitate to call the responsible authorities if this plant was put into production without addressing these issues.

Quote

...wanted a answer to a simple question that was not answered

not for lack of trying... and we did not get our own questions answered.

Quote from kimalia

I'm completely aware that there are regulations. in the EU and in the country that I currently reside in.
But again, as previously mentioned. Regulations has nothing to do with this post, and is completely off topic.

so why you did ask?

as I know in the EU you can't even use a fence, you have to use a bullet proof wall (unless you want to kill someone)

Quote from kimalia

n the end, as previously stated I'm no expert. I am a buyer who wanted a answer to a simple question that was not answered, so I dumped the light curtains and took the less ''fancy'' rout and ordered a fence instead.

This question was answered and you as owner have to go to jail if someone has died (at least in the EU)

Think about that