Laser displays/shows - UK laws - Help?

[Pangolin]

Hi Andy_con,

I would highly recommend you reveiw the Theses of John O'Hagan from the UK National Radiologocal Protection Board. The theses discusses risk analysis of doing laser shows. It is particularly good for audience scanning shows, but his principals of risk analysis are applicable for all show types:
http://www.pangolin.com/resguide09b.htm

If you plan on doing audience scanning, don't do it unless you have experience. Also, I would highly recommend you read my article on the subject:
http://www.pangolin.com/resguide09a.htm

Best regards,

William Benner

[andy_con]

Lucky... though you do have to pay for import taxes Still, a very small price to pay considering the huge hassle of doing laser shows in the states.

Hey Andy, when ya get it set up, take some pics when the venue is hoppin'!

shame i had the scanners 1 day and broke them LOL - i broke a mirror.

dont worry once i get going there will be millions of pics, i do like a good old photo. and ill do some pics and vids of the party "hoppin" LOL

did you check my site boomdog? www.laser-man.co.uk big section on your scanner.

[andy_con]

oh really kool, so i dont need a license or anything like that?

i was gona go with beam shows above the crowd, my laser is only 100mw 532nm so should be fine once in scanning routing

Don't audience scan, before you have taken time to read up and understand the dangers associated(there are some very good articles in the Pangolin resource section). A laser that 'is only 100mw' can still do damage to a bystanders eyes if used incorrectly.

oh i will do some reading dont worry, im not just going to do a show without knowing anything.

when i say audience scanning, i mean above their heads not at them. So they could put there hands up into the beam but thats it.

a 100mw 532nm laser is pretty powerful i can light a match form 27metres, but once scanning it becomes ok. But i still dont intending on aiming it in peoples eyes.

[Pangolin]

Hi Andy_con,

One more thing about those scanners. The mirrors are really way too thin. That's the fault of the manufacturer (see my previous post about people foolishly thinking that thin mirrors are better). I recommend you put some epoxy on the back side of these mirrors after you have mounted them. Just a thin layer will do it. This will make the mirror artificially thicker, and will also "kill the Q" of resonances related to the mirror.

Bill

[andy_con]

Hi Andy_con,

I would highly recommend you reveiw the Theses of John O'Hagan from the UK National Radiologocal Protection Board. The theses discusses risk analysis of doing laser shows. It is particularly good for audience scanning shows, but his principals of risk analysis are applicable for all show types:
http://www.pangolin.com/resguide09b.htm

If you plan on doing audience scanning, don't do it unless you have experience. Also, I would highly recommend you read my article on the subject:
http://www.pangolin.com/resguide09a.htm

Best regards,

William Benner

i will have a read of that mate, cheers

[andy_con]

Hi Andy_con,

One more thing about those scanners. The mirrors are really way too thin. That's the fault of the manufacturer (see my previous post about people foolishly thinking that thin mirrors are better). I recommend you put some epoxy on the back side of these mirrors after you have mounted them. Just a thin layer will do it. This will make the mirror artificially thicker, and will also "kill the Q" of resonances related to the mirror.

Bill

ok cheers, but i dont get what you mean????

[Pangolin]

I guess a picture is worth a thousand words. Unfortunately I can not provide a picture because I myself do not have these scanners. I only saw them at a client's site, and then recommended they do the same.

Basically, you just put epoxy on the back of the mirror. That makes the mirror artificially thicker. It also will kill the Q of the resonances. If you don't undersand this technical term, then you will just have to trust me on that one...

You don't need much epoxy either. Just a thin layer. But not too thin...

Bill

[JimBo]

Andy,
did you manage to get a copy of the HSE regs?

I have a copy that I can scan and put a link to.
Its 65 pages long and covers what is expected of you to put a laser system and show on safetly.

It also has the MPE equations to use for audience scanning.

Unlike the US though you dont need to get a varience or license to do the show.

Jim

[jian725]

Hi Andy_con,

One more thing about those scanners. The mirrors are really way too thin. That's the fault of the manufacturer (see my previous post about people foolishly thinking that thin mirrors are better). I recommend you put some epoxy on the back side of these mirrors after you have mounted them. Just a thin layer will do it. This will make the mirror artificially thicker, and will also "kill the Q" of resonances related to the mirror.

Bill

:?
I think that just temp ,not the ultimate put the axe in the helve.
If the mirror broken a little (if the originally mirror long 10mm,now 8mm only and you re-install it).
Then the mirror inertia was change,must re-adjust the driver.

If "put some epoxy on the back "then the mirror would be not balance.
The laser image bad ,probably the beeline become a curve and more noise :roll:

JIAN

[Pangolin]

Hi Jian,

Epoxy has far less mass than glass. And thus, the contribution to inertia is tiny.

Yes, it is imbalanced, and worst, could result in what's known as a "dynamic forcing function". BUT, it is the lesser of two evils...

If the mirror is too thin, the frequency of longitudinal resonances will be very low, and most certainly excited by scanning, especially faster than around 15K. By putting epoxy on the back, you artificially "thicken" the mirror, thus raising the resonant frequency. And more importantly, you "kill the Q of the resonance" since epoxy is not a very stiff material, so you will not observe the result of the resonance or the dynamic forcing function.

The best answer would be to install thicker mirrors, but that may not be possible. For one thing, the slot in the shaft of cheap scanners may not be thick enough to accommodate thicker mirrors. For another thing, to obtain thicker mirrors after the fact may very well cost more than the original scanner purchase...

So again, epoxy is a simple solution for people. Everyone can get epoxy, no matter where they are located in the world. Not everyone can get thicker mirrors... It's a cheap solution, but it will work in a pinch

Bill

PS: Actually the absolute best solution would be to use Cambridge model 6215 scanners, but of course that is more costly than epoxy