Laser pointer discussion. Read/write reviews of laser pointers and laser pointer companies. Learn about all types of laser pointers and lasers





One laser store meets all your needs

Go Back   Laser Pointer Forums - Discuss Laser Pointers > Lasers > Laser Shows





Reply
 
LinkBack Thread Tools Display Modes
Old 10-06-2011, 12:05 AM #1
Junior Member
 
Join Date: Oct 2011
Posts: 4
Rep Power: 0
Laz321 is on a distinguished road
Laz321 Laz321 is offline
Junior Member
 
Join Date: Oct 2011
Posts: 4
Rep Power: 0
Laz321 is on a distinguished road
Default Safety Concern Regarding Very Basic Projector

Hello everyone, this is my first post here so I hope it in the correct place. I have been planning on doing this simple project for a while now but am no having some concerns about safety. I am building this project for home use but am concerned about damage to my own or family member's eyes.

The basic layout is as fallows:
2x Slow DC Motors (Roughly 45 rpm)
2x Defraction Gratings (2 Plain) attached to two plexiglass discs
1x mirror
1x Laser module with heatsink

The laser would reflect off the mirror which I may eventually have rotating, through the two slowly rotating defraction gratings attached to the motors. I believe this produces 25+ beams which in turn are again split, producing I believe hundreds of beams.

My concerns are the following. I REALLY wanted to use a 445nm laser because of the color. I purchased one from eBay which was originally intended to be one watt, however I asked the seller if he could tune it down for the use I had in mind. He was able to bring it down to about 250 mA of current with an output of 169mw max. I also know from shining my green laser pointer through one grating that the center beam is still relatively powerful.

Is this thing doomed to be an unsafe projector or can I modify it to increase the safety of it? Could I unfocus the beam to make it wider or reflect if off more surfaces? If not, I will simply convert to module into a laser pointer and get a significantly less powerful module at a different wavelength.

Thanks,
Laz

Edit: Here is the module for anyone curious: http://www.ebay.com/itm/180707971676...84.m1497.l2649



Last edited by Laz321; 10-06-2011 at 12:07 AM. Reason: Link to module
Laz321 is offline   Reply With Quote


















Old 10-06-2011, 12:10 AM #2
ShortyInCanada's Avatar
Class 2M Laser
 
Join Date: Mar 2011
Location: Beautiful British Columbia
Posts: 617
Rep Power: 552
ShortyInCanada has a reputation beyond reputeShortyInCanada has a reputation beyond reputeShortyInCanada has a reputation beyond reputeShortyInCanada has a reputation beyond reputeShortyInCanada has a reputation beyond reputeShortyInCanada has a reputation beyond reputeShortyInCanada has a reputation beyond reputeShortyInCanada has a reputation beyond reputeShortyInCanada has a reputation beyond reputeShortyInCanada has a reputation beyond reputeShortyInCanada has a reputation beyond repute
ShortyInCanada ShortyInCanada is offline
Class 2M Laser
ShortyInCanada's Avatar
 
Join Date: Mar 2011
Location: Beautiful British Columbia
Posts: 617
Rep Power: 552
ShortyInCanada has a reputation beyond reputeShortyInCanada has a reputation beyond reputeShortyInCanada has a reputation beyond reputeShortyInCanada has a reputation beyond reputeShortyInCanada has a reputation beyond reputeShortyInCanada has a reputation beyond reputeShortyInCanada has a reputation beyond reputeShortyInCanada has a reputation beyond reputeShortyInCanada has a reputation beyond reputeShortyInCanada has a reputation beyond reputeShortyInCanada has a reputation beyond repute
Default Re: Safety Concern Regarding Very Basic Projector

To put it simply, there is a reason why the US bans lasers over 5mw.
Safety.
A 169mw beam, even if broken up by diffraction gratings and counting the loss from the bounce mirror would still be far too dangerous. Although the 445 color would be suitable for blink reflex the power absorbed before closing the eye would still be far too damaging.

Don't do it !

ShortyInCanada is offline   Reply With Quote
Old 10-06-2011, 12:37 AM #3
Cyparagon's Avatar
Class 4 Laser
 
Join Date: Sep 2007
Location: Wisconsin
Posts: 9,177
Rep Power: 17961
Cyparagon has a reputation beyond reputeCyparagon has a reputation beyond reputeCyparagon has a reputation beyond reputeCyparagon has a reputation beyond reputeCyparagon has a reputation beyond reputeCyparagon has a reputation beyond reputeCyparagon has a reputation beyond reputeCyparagon has a reputation beyond reputeCyparagon has a reputation beyond reputeCyparagon has a reputation beyond reputeCyparagon has a reputation beyond repute
Cyparagon Cyparagon is offline
Class 4 Laser
Cyparagon's Avatar
 
Join Date: Sep 2007
Location: Wisconsin
Posts: 9,177
Rep Power: 17961
Cyparagon has a reputation beyond reputeCyparagon has a reputation beyond reputeCyparagon has a reputation beyond reputeCyparagon has a reputation beyond reputeCyparagon has a reputation beyond reputeCyparagon has a reputation beyond reputeCyparagon has a reputation beyond reputeCyparagon has a reputation beyond reputeCyparagon has a reputation beyond reputeCyparagon has a reputation beyond reputeCyparagon has a reputation beyond repute
Default Re: Safety Concern Regarding Very Basic Projector

Quote:
Originally Posted by ShortyInCanada View Post
A 169mw beam, even if broken up by diffraction gratings...would still be far too dangerous.
Why do you say that?
__________________
A problem well stated is a problem half solved.
Cyparagon is offline   Reply With Quote
Old 10-07-2011, 05:17 PM #4
ShortyInCanada's Avatar
Class 2M Laser
 
Join Date: Mar 2011
Location: Beautiful British Columbia
Posts: 617
Rep Power: 552
ShortyInCanada has a reputation beyond reputeShortyInCanada has a reputation beyond reputeShortyInCanada has a reputation beyond reputeShortyInCanada has a reputation beyond reputeShortyInCanada has a reputation beyond reputeShortyInCanada has a reputation beyond reputeShortyInCanada has a reputation beyond reputeShortyInCanada has a reputation beyond reputeShortyInCanada has a reputation beyond reputeShortyInCanada has a reputation beyond reputeShortyInCanada has a reputation beyond repute
ShortyInCanada ShortyInCanada is offline
Class 2M Laser
ShortyInCanada's Avatar
 
Join Date: Mar 2011
Location: Beautiful British Columbia
Posts: 617
Rep Power: 552
ShortyInCanada has a reputation beyond reputeShortyInCanada has a reputation beyond reputeShortyInCanada has a reputation beyond reputeShortyInCanada has a reputation beyond reputeShortyInCanada has a reputation beyond reputeShortyInCanada has a reputation beyond reputeShortyInCanada has a reputation beyond reputeShortyInCanada has a reputation beyond reputeShortyInCanada has a reputation beyond reputeShortyInCanada has a reputation beyond reputeShortyInCanada has a reputation beyond repute
Default Re: Safety Concern Regarding Very Basic Projector

As the OP stated, "I also know from shining my green laser pointer through one grating that the center beam is still relatively powerful. "

The chances of those centre spots being above a safe thresh-hold is too great.
As a new member the guy is showing signs of the proper thinking.
Better safe than sorry.
If he was to try out a lower powered unit in the completed assembly and physically test the output of those centre spots to see the actual PEAK output under the conditions given then extrapolate the results from a much higher output power and determine them to be completely safe even in a state of failure, well then I will stand corrected and take all the verbal abuse that you can throw at me.
But as it will have caused even one more person to get serious about the safety and make them consider the possibility of the consequences from their build suffering failures (say one of the diffraction gratings comes loose and falls away) then I will say that it was worth it.
Sometimes I'm such a glutton for punishment.
ShortyInCanada is offline   Reply With Quote
Old 10-07-2011, 05:44 PM #5
Junior Member
 
Join Date: Oct 2011
Posts: 4
Rep Power: 0
Laz321 is on a distinguished road
Laz321 Laz321 is offline
Junior Member
 
Join Date: Oct 2011
Posts: 4
Rep Power: 0
Laz321 is on a distinguished road
Default Re: Safety Concern Regarding Very Basic Projector

Thanks for the replies guys. Is there any low cost way to approximate or get an exact reading on the power of the center beams? I've looked at some laser power measuring devices and they all seem to run upwards of $250+
Laz321 is offline   Reply With Quote
Old 10-08-2011, 09:14 PM #6
Class 2 Laser
 
Join Date: Mar 2009
Location: California
Posts: 328
Rep Power: 15
whatsupadrian is a glorious beacon of lightwhatsupadrian is a glorious beacon of lightwhatsupadrian is a glorious beacon of lightwhatsupadrian is a glorious beacon of lightwhatsupadrian is a glorious beacon of lightwhatsupadrian is a glorious beacon of light
Send a message via AIM to whatsupadrian
whatsupadrian whatsupadrian is offline
Class 2 Laser
 
Join Date: Mar 2009
Location: California
Posts: 328
Rep Power: 15
whatsupadrian is a glorious beacon of lightwhatsupadrian is a glorious beacon of lightwhatsupadrian is a glorious beacon of lightwhatsupadrian is a glorious beacon of lightwhatsupadrian is a glorious beacon of lightwhatsupadrian is a glorious beacon of light
Send a message via AIM to whatsupadrian
Default Re: Safety Concern Regarding Very Basic Projector

I have a laserbee hobiest laser power meter that may be perfect for you. The one you take readings with a multimeter, ill include the multimeter.
25$ + ship where are you located?
whatsupadrian is offline   Reply With Quote
Old 10-08-2011, 11:16 PM #7
Junior Member
 
Join Date: Oct 2011
Posts: 4
Rep Power: 0
Laz321 is on a distinguished road
Laz321 Laz321 is offline
Junior Member
 
Join Date: Oct 2011
Posts: 4
Rep Power: 0
Laz321 is on a distinguished road
Default Re: Safety Concern Regarding Very Basic Projector

Quote:
Originally Posted by whatsupadrian View Post
I have a laserbee hobiest laser power meter that may be perfect for you. The one you take readings with a multimeter, ill include the multimeter.
25$ + ship where are you located?
That would be great. I'm located in Connecticut. Do you have any pictures to give me an idea of how it works and would you accept Paypal?

EDIT: Also I was wondering I'm using some Dewault laser glasses which are supposed to magnify the weak red lasers from laser levels. I've tested them with my green laser pointer which is roughly 80mW (Not wearing them!) and no light shines through at all. Now these are not marketed as laser safety goggles, but seam to work somewhat well. Do you think these are sufficient for use with lasers below 200mw?

Last edited by Laz321; 10-08-2011 at 11:28 PM.
Laz321 is offline   Reply With Quote
Old 10-09-2011, 05:35 AM #8
Bionic-Badger's Avatar
Class 4 Laser
 
Join Date: Oct 2007
Location: Oregon, USA
Posts: 5,478
Rep Power: 3157
Bionic-Badger has a reputation beyond reputeBionic-Badger has a reputation beyond reputeBionic-Badger has a reputation beyond reputeBionic-Badger has a reputation beyond reputeBionic-Badger has a reputation beyond reputeBionic-Badger has a reputation beyond reputeBionic-Badger has a reputation beyond reputeBionic-Badger has a reputation beyond reputeBionic-Badger has a reputation beyond reputeBionic-Badger has a reputation beyond reputeBionic-Badger has a reputation beyond repute
Bionic-Badger Bionic-Badger is offline
Class 4 Laser
Bionic-Badger's Avatar
 
Join Date: Oct 2007
Location: Oregon, USA
Posts: 5,478
Rep Power: 3157
Bionic-Badger has a reputation beyond reputeBionic-Badger has a reputation beyond reputeBionic-Badger has a reputation beyond reputeBionic-Badger has a reputation beyond reputeBionic-Badger has a reputation beyond reputeBionic-Badger has a reputation beyond reputeBionic-Badger has a reputation beyond reputeBionic-Badger has a reputation beyond reputeBionic-Badger has a reputation beyond reputeBionic-Badger has a reputation beyond reputeBionic-Badger has a reputation beyond repute
Default Re: Safety Concern Regarding Very Basic Projector

Yes, those laser enhancement goggles work well (almost too well) with green lasers.
Bionic-Badger is offline   Reply With Quote
Reply





Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are On











Loading
















Privacy Policy | Advertising Disclaimer | Terms of Use


 


All times are GMT. The time now is 11:06 PM.


Powered by: vBulletin
Copyright ©2000 - 2017, Jelsoft Enterprises Ltd.
Search Engine Friendly URLs by vBSEO
Privacy Policy | Advertising Disclaimer | Terms of Use
Copyright (C) 2017 Laser Pointer Forums, LLC