Frickin' Lasers

[Johnnycrash]

Have any of you out there had any experience with these or similar laser pointers??

http://www.amazon.com/gp/product/B00R73 ... U5OH73UZ8M

http://www.amazon.com/gp/product/B00JJX ... T0K02X500M



From what I can tell, all you need to do is hook up an appropriate power source, and presto, instant cat toy.

I am NOT looking to install these into a model, but it is model relented usage. I want to build two main jigs to help chop into/up models. Getting a straight cut is always a pain, even more so on compound curved surfaces. As well, making a hole for tubing to be inserted is hard to map out on said surfaces. The circle jig would comprise about 6 or so dot lasers. They could be adjusted for different sizes of circles, and would spin to draw the circle on the complex model surface. (I have a great kitbash, but cutting into it to mount a deflector dish has stopped me dead - hence the laser idea)

With these lasers, and the right jig, I'll make that all easier. Hopefully.

But, I have NO experiences with these, or any lasers. Thoughts??

[Ant]

Laser diodes are constant current devices like LEDs, but are far more sensitive to abuse. Whereas you can get by using a series resistor to limit the current on a low power LED, you're more likely to damage a LD using just a resistor due to operating changes whilst in use (e.g. temperature)

These cheapo LDs are usually still supplied with a built in series resistor to keep the costs low low low, but you really need a proper constant current driver circuit for long term reliable operation.

If you want to keep it simple, stick with using button cells as these have a high internal resistance anyway and are usually incapable of supplying enough current to damage the device even in a runaway situation.

Also the flying leads and solder connections on these things are extremely fragile and won't take much wiggling!

[Johnnycrash]

Thanks Ant. I thought I may have had to quite this entire forum when no one answered me instantly.

So, I ONLY need a power source, and I should be good?? And you suggest the button batteries. Perfect if so. For the Circle Maker, the laser head or whatever it's called needs to spin. Hard to do with a big power supply. It doesn't need to spin at high speed, just so I can poke the next red dot with a Sharpie to show where to cut.

And if I DO burn them out, they are cheap. I can get 10pcs for $4.00.

Now, all I need to do is engineer the jigs. Ugh!! Oh, and figure out how to wire 6 diodes together in a way they get ONLY the power they need, and I can turn them all on with one switch. Ugh!!

[Ant]

The traditional way to get a laser to paint a circle is to shine it onto a mirror mounted at an angle on the end of a spinning motor - that way none of the laser assembly needs to spin.

Shine the result onto another spinning mirror and you can create all sorts of cool lissajous patterns

https://www.howtosmile.org/resource/smi ... 00-001-785

[Johnnycrash]

Very true. But... Cool yes, but that's a little complicated than I need.

I am looking at being able to resize the circle to precise (enough) dims by moving them out/inward together (like this or something), and spinning at probably no more than 10rpm or so.

I'll have to get a few of the diodes and play with them a bit.

[MillenniumFalsehood]

Oh, and figure out how to wire 6 diodes together in a way they get ONLY the power they need, and I can turn them all on with one switch. Ugh!!

This isn't too big of a deal, honestly. Just wire them all in series and put current limiting resistors on them, and it should work just fine. Then put a power switch between the battery and the circuit and you're good to go.

[Johnnycrash]

This isn't too big of a deal, honestly.

Thanks. That is pretty easy. I may put an eye out yet.

[MillenniumFalsehood]

That's why God gave you two.