Please recommend a laser for a diy spirograph.

Hi Folks - havent been around in a while.

For history's sake - I was pretty into Argon Multiline a couple of years ago and ended up selling my kit as it wasnt getting used and my interested changed.

Well - My kiddos are 2 and 3 now, and I think they would like to play with a spirograph - so I'm thinking of designing one with an interface they could use.

I'm not interested in high high power... I want safety first - so I would like recommendations on a lab-style, or other host that could be converted to lab-style blue laser in a low mw range (under 30mw I would think).

I want the dot to be safely visible. The kids will not have access to the laser itsself, so they will not be able to look into the aperture.... I will be mounting everything on a board or something similar and will set it in a place so they can't get in the beam-path.

So - my questions are:
1) What mw rating would you recommend for a good spirograph that will allow direct viewing of the dot without harm? Is it also possible to have enough mw rating for some beam effects via smoke, fog, etc?
2) Are there any current lasers available that meet this criteria?
3) I would like a 100% duty cycle and can add a cooling fan if needed.

Thanks in advance for your suggestions!

If your kids are 2 and 3 I'd keep the power way down under
3mW...
You can get some cheap 532nm and 650nm Lasers off eBay.
You will need to verify their output since sellers on eBay can
no longer sell Lasers >5mW but they still do and mark them
5mW.

Or you could get a laser from a member here that has a LPM
to verify the outputs to be <3mW.


Jerry

You can contact us at any time through our Website: J.BAUER Electronics

You'll really just have to experiment. Also, if you want a blue in lower mW ranges you'll need to buy one of those single mode lasers. I'm not even sure if even they go as low as 30mW.

Before you buy any lasers buy some goggles. When you're working with optics, there's a much greater chance that you'll be exposed to reflections from the laser. Don't let your kids in the room when you're working on it as well.

Yup - already have a pair from my argon days... OD4 from dragonlasers..

I'm now thinking about using some sort of attenuation - I wonder if I could split the beam several times... So if I had a 70mw then I could get three 25/75 splitters and end up with around 1mw.. and still be able to go up in power down the road for other uses.

Just use some ND filters... Much easier and
less expensive.


Jerry

You can contact us at any time through our Website: J.BAUER Electronics

can I use ND filters to attenuate output from high power lasers and then measure them readable on lower power LPMs in some predictable manner?

Yeah... but you must test the power reduction ratio
through your specific ND filter at the wavelength of
the Laser you are testing.
Not all ND filters behave the same at all Laser
wavelengths.


Jerry

You can contact us at any time on our Website: J.BAUER Electronics

A standard 2mW red module like this one might be your best option.