Moving Diffraction Grating Build - Any Ideas to Make it Better?

[BrewCityMusic]

Well I finally put together two of these builds to use as accents for the shows - pretty simple concept, the laser is an Aixiz Labbie (one at 118mW, one at about 92-ish) that runs through a diffraction grating revolving at 3rpm, then through 2 static diffraction gratings before exiting the aperature...

I gave them the first test on Wed night at our show, but had some stability troubles with one of the labbies (one has a REALLY touchy sweet spot and sometimes will strobe when first fired up, so I turned it off just to be safe) - hence only one is shown in the photo:

The build uses a couple of old-style American DJ "Groove Wheels" with the controller board and "guts" removed, as well as the original optics:

Anyhow, what I'm searching for here are some ideas to make these more unique - don't get me wrong, they're a really nice "Laser Moonflower" effect as they are, I just was hoping someone else has built similar units and maybe hit on something even MORE unique...

The next concept is a pair of lumia wheel lasers to illuminate the dance floor, BTW, using a couple of the ADJ "Topaz" water-wheel effects lights (one has been prototyped already and it's an amazingly simple build) - Again though, any input on these builds would be greatly appreciated!

 

[ElektroFreak]

^It's a bit off-topic, bit it occurred to me that some of your troubles with the Aixiz labbies may be due to a lack of warm-up. I've noticed that often they will behave strangely for the first 10 minutes or so, and then they settle down.. of course, it's pretty commonplace for any cheap dpss laser to misbehave a little until it warms up.

 

[BrewCityMusic]

Thanks for the tip, EF - here's a question, though, if the laser "strobes" until it warms up, is that strobing potentially dangerous to the laser? Thanks!

 

[ElektroFreak]

No, since any strobing caused by driver instability will be limited by the circuitry of the driver, so no transients should hit the diode. Strobing caused by the inner workings of the laser head itself (the crystals) will not damage the laser since this is not occurring at the diode, but rather inside the crystals. In truth, at it's worst this strobing could be compared to modulation, which is typically not dangerous either.

 

[HIMNL9]

If for "make them more unique" you're speaking about effects (grating), i can suggest you to do the same thing i've done in the past, take two motors at different speeds, like 1 and 3 rpm, put a diffracter on each one, and let the beam pass through both of them ..... continuously random diffractions (just keep the two diffractors as close as possible, practically one almost touching the other)

Just another of my crazy ideas

 

[Jaseth]

I have a couple of ideas which might be of interest:
A green labby @ ~200mW which shines onto a large chrome ball and then through a diffraction grating. Onto the chrome ball there would at certain intervals (of about 1 minute) be dripped a drop of oil. This slow dripping should not be too difficult to achieve with a pipette type container. Two small motors would constantly, slowly turn the chrome ball.

I actually saw a small version of this at a bar I often go to - They just had a cheap ~50mW green labby pointing at a small turning ball with no diffraction grating (you probably know the effect).
The aim would be to get the oil to run very slowly across the area the laser is shining on while making the pattern change often by turning the ball. If the surface is flat enough (read: large ball) and the ball is not completely smothered in oil the directed beam should not be too spread out, and if the diffraction grating is close to the ball, 200mW should be powerful enough to be seen clearly even after passing the grating. This would mostly be a really awesome watery effect to project onto walls.

Another possibility would be.. oh darn I forgot it now.. I will try to remember it and hit you back with a couple more ideas.
Any specific requests for the shows? I mean, would you prefer visible beams, wall projections, controlled or natural effects?

 

[BrewCityMusic]

HIMNL: I tried your idea, but it isn't going to conveniently fit in the enclosure (although I'm already searching for another couple of enclosures as I really like the effect)

Jaseth: Your idea might take a little work, but I'll definitely give it a go - sounds unique as hell (the trouble I see would be with collecting the oil to re-drip, but that might actually work OK with a small peristasic pump, which I believe I may have laying around somewhere from an old lamp) ...

As to what I'm looking for, probably the most important would be a nice trippy projection for the dance floor (hence the limia wheel idea) - the diffraction lasers will add a nice slow, groovy "moonflower" effect to the racks...

Thanks, Guys!

 

[laserist]

It might be interesting to go after something of a moire pattern with your diffraction gratings usig some sort of rotating spiral disk

. Back in the day - Laserium had a number that had a similar diffraction grating theme. We used a segment from a liquid crystal display to fuzz the beam to the music, and at the end the "stationary" diffraction grating was spun at 10 or so rpm in alternating directions to the music. It was an interesting effect - but the spinning didn't make up for three minutes of "Set the Controls for the Heart of the Sun" boredom.

 

[Jaseth]

Yes it is indeed unique! I am not really sure about what oil they used but I would guess that it was just silicone oil or something similar. It has to be fairly thick so it flows slowly, but thin enough to be a layer rather than a blob.
Good idea with the pump! It does give a trippy effect, it's a bit like a mix between the reflection of melting plastic and the standard reflection from a piece of shiny metal. I always like experimenting with unique effects - while scanners and diffraction gratings are awesome sometimes you just want a random, messy but magical pattern.

No problem Let me know if you manage to make it!

 

[HIMNL9]

@ BrewCityMusic:

I made a mini unit this way for a friend, a pair of years ago, and solved the space problem in this way (the attached draws, not in scale but i think it's clear enough ).

Just need attention working on the gears, and probally you need more than 2 ( i breaked the first 2 for too much impatience, LOL), but can be done

About the oil, i had a different idea, but is so strange that i need to check it before