Can anyone help me with a purchase???

[Stuka]

I am interested in a similar solenoid-shutter project and was wondering - if you're using a higher-power laser (300mW or higher), what would most of you consider a safe "target" material for the beam once it is blocked or diverted?

Thanks -

RR

[Jem]

O.K. Guys. You've sort of convinced me that I don't *really* need the shutter on Ebay. I just thought the price was reasonable and I could 'play' with it and perhaps learn something along the way.

I've ordered a solenoid from farnells as Simon suggested and will fabricate a mount for it.

I too am a little puzzled as to the *Real* point of a shutter unless it has some external controlling circuitry that monitors various functions of the projector. I was simply going to wire this into an emergency stop button. Alternatively, I suppose I could wire a relay into the modulation circuit to cut the +5v to the lasers when the emergency button was pressed.

When I arrive at the UK meet with my projector are any of you folks going to ask if I have a laser shutter fitted before I can use the projector? - I thought not, maybe i'm missing something here.

Although it seems to be a legal requirement to have a safety shutter I seem to be missing the point of it, perhaps someone can explain it to me in very simple terms Surely there are better alternatives.

Anyways, i'll fit one just so my projector has one

Cheers

Jem

[p1t8ull]

I too am a little puzzled as to the *Real* point of a shutter

Purely safety Jem. The shutter *should* be gravity closed, energised open and wired into an interlock circuit. The controller is the only thing that signals it to open, which it will do - so long as all the other interlocks are closed. Interlocks can include the emergency stop, a keyswitch, tamper switches on the projector housing etc.

Without a gravity shutter, some lasers will project a static, full intensity beam as soon as the controller is powered off...

I was once asked to prevent the laser from ever projecting, unless the target screen was fully lowered, so just rigged up a microswitch on the screen housing and tapped into the interlock circuit.

[buffo]

The shutter *should* be gravity closed

Actually, I think over here the CDRH requires that it be SPRING closed, not just gravity. But yeah, like you said - the only thing that opens it is the controller, and then only when everything is kosher.

Re: A beamstop... I don't think that's really necessary until you get up into the multiple-watt lasers. (Then a nice block of carbon would work well.) But there's certainly nothing wrong with dumping 300-500 mw of light onto the metal arm of the shutter. (Or using a mirror to reflect it onto the inside of the case.)

Adam

[Banthai]

Hi Jem

A Prime example from me is that when i used to run the alphalite software ... sometimes it would crash halfway through a show and would not blank the laser .... which left a single 300mW beam directed straight into the audience .... if it happened ( and it did quite often ) i could hit the estop closing the shutter to minimise the situation ... although now using Mamba i never have seen the same situation

also at the control desk along with the E-stop i have a key switch .... which is also connected to the shutter .... so if i have to leave the desk for any reason the key is chained to me and no one else is able start up the show ....

basicaly thats it for me

all the best ... Karl

[Jem]

Thanks Guys, I'm getting a better understanding of it now. I'll put it together as I think best and let anyone who's interested have a peek at it at the UK meet. You can then all then throw in your tuppence worth

As always, everything's a learning curve when you're new to it.

Many thanks

Jem

[fluff]

Hi Jem

Just to let you know, there is no specific law on operating show lasers in the UK.

The HS (G) 95 doc are just guidlines to follow.

This is only ever an issue when doing a risk assessment for the local authorities. You can , of course , be taken to task if you blind someone, through the normal legal channels!

The only other consideration is your own conscience. Most responsible laserists will ensure their shows are safe. Most lower power commercial units don't have a mechanical shutter. Interlocks and keyswitches which kill the output are the usual safety devices, as already mentioned.

When I did shows I always made sure that if a single beam popped out for any reason, the laser was pointing straight out, above head height !

The big problem is when scanners seize . If they seize in the wrong position you have a problem! Fortunately this is a very rare occurance. I've only had one scanner fail in the last three or four years ( a CTI 6210 ! ). It overheated due to poor thermal transfer to the bed.

I'll tell you more about it at the meet.

I also suggest you get a copy of the HS (G)95 and have a read here http://www.hse.gov.uk/pubns/INDG224.htm


Regards

Fluff

[Jem]

Hi all

Fluff, thanks for the comprehensive reply. I already have the HSG95 document along with bucketfulls of other stuff pertaining to laser safety etc. I was also on the Laservisuals course along with Andy from AC Lasers, Simon (Pit8ull) and Rob (Stanwax).

I realise that there is no specific law relating to operating lasers in public. However, in agreement with yourself, a lack of understanding and a failure to follow guidelines are just asking for trouble. If someone gets injured the door is wide open for the Health & Safety people and the no win no fee lawyers to have a go at you. In the event that best practice hasn't been followed with regard to safety issues they'll probably win as I would have no defence - I knew about the guidelines and chose not to follow them. Even if I didn't know about the guidelines, ignorance of the law is (apparently) no excuse.

One of the problems/benefits is that I work in (Ophthalmic) Optics. I'm therefore only too well aware of the potential risks to the eyes from stray beams and want to do everything I can to stop it happening. Having said that, i've scoured the web and many professional optical journals trying to find evidence of persons being injured with laser 'Projectors' used in entertainment. The only injuries I can find are more from Lab type and industrial laser accidents. If anyone can provide absolute concrete proof of an eye injury from a laser projector being used in an entertainment environment i'd love to hear from them.

So, in conclusion, i'm still very much a 'novice' when it comes to projectors and i'm very eager to learn from others experiences as to what is 'good' and what isn't. I would like to thank everyone for their input and I respect the time and effort that you have all put in to be able to pass on the benefits of that experience to newcomers like myself. In time, I too hope to be able to pass on information. Some of the questions I ask are probably a bit 'simple' but i've quite often heard from others via PM who have thanked me for asking a certain question that they wanted answering, but that they were too afraid to ask in case they looked stupid. Me, I don't care if I look daft, I think it's more important to know the answer rather than guessing.

I realise that i'm rambling on a bit now, possibly as a result of the (very) nice (almost empty) bottle of red that's sat at the side of me. I've even lost track of what point I was trying to make, ah well, that's life

Cheers everyone!

Jem

[steve-o]

Thanks You-all. It's clearer now, Is the interlock a microswitch for the cover being opened? I'll put in a shutter, a remote control e-stop and a hardwire e-stop, and I suppose a key-switch. I wont be running any 'conventional' Software/Dacs/Amps/Scanners yet. Money's tight and as far as I can figure its 550 for the DTs, 500 for the Pango hobby version (anyone have one of those yet?) and I blew out my reds so there is a monitary penalty for being stupid there.. heh.. live and learn..the hard way..thats how I seem to learn most of lifes lessons.

[fluff]

Hi all

Fluff, thanks for the comprehensive reply. I already have the HSG95 document along with bucketfulls of other stuff pertaining to laser safety etc. I was also on the Laservisuals course along with Andy from AC Lasers, Simon (Pit8ull) and Rob (Stanwax).

I realise that there is no specific law relating to operating lasers in public. However, in agreement with yourself, a lack of understanding and a failure to follow guidelines are just asking for trouble. If someone gets injured the door is wide open for the Health & Safety people and the no win no fee lawyers to have a go at you. In the event that best practice hasn't been followed with regard to safety issues they'll probably win as I would have no defence - I knew about the guidelines and chose not to follow them. Even if I didn't know about the guidelines, ignorance of the law is (apparently) no excuse.

One of the problems/benefits is that I work in (Ophthalmic) Optics. I'm therefore only too well aware of the potential risks to the eyes from stray beams and want to do everything I can to stop it happening. Having said that, i've scoured the web and many professional optical journals trying to find evidence of persons being injured with laser 'Projectors' used in entertainment. The only injuries I can find are more from Lab type and industrial laser accidents. If anyone can provide absolute concrete proof of an eye injury from a laser projector being used in an entertainment environment i'd love to hear from them.

So, in conclusion, i'm still very much a 'novice' when it comes to projectors and i'm very eager to learn from others experiences as to what is 'good' and what isn't. I would like to thank everyone for their input and I respect the time and effort that you have all put in to be able to pass on the benefits of that experience to newcomers like myself. In time, I too hope to be able to pass on information. Some of the questions I ask are probably a bit 'simple' but i've quite often heard from others via PM who have thanked me for asking a certain question that they wanted answering, but that they were too afraid to ask in case they looked stupid. Me, I don't care if I look daft, I think it's more important to know the answer rather than guessing.

I realise that i'm rambling on a bit now, possibly as a result of the (very) nice (almost empty) bottle of red that's sat at the side of me. I've even lost track of what point I was trying to make, ah well, that's life

Cheers everyone!

Jem

Hey Jem

Bit early for the pop

I also don't know of any documented incident of eye damage at a laser show.

However, this may be due to the fact that most people would probably be unaware that they had damaged their eyesight, unless they had regular checkups from someone experienced in retinal burns. The odds of that happening are slim to none ( evidently )!

This is down to the very nature of laser exposure on the eye.

This applies especially to nightclub enviroments. Most of the customers are so drunk/pilled , you could poke them in the eye with a sharp stick, and they wouldn't notice the next day !

The fact is, it probably has happend, but the victim was/is unaware.

Obviously a smack in the eye with a multiwatt yag is a different story !

I am sure that legislation is on its way though, so if your on the case now, you'll be ok when the law is introduced.

Fluff