Construction questions - Realignment avoidance, AR glass, and taming fat beams...

[Stuka]

OK -
A few questions here for those folks who have completed a projector or two:

(1.) For those who move their projectors a lot -
Once you have found the "sweet spot" for your optics alignment, do you use anything (thread seal, etc.) on the optics adjustment and mounting hardware, or is periodic realignment just one of those "annoyances" you learn to live with?

(2.) Custom AR glass -
My RGB projector case aperture would require a 2" x 6" piece of glass to seal the opening (oversized aperture for "expansion plans"...). Any recommendations for a source for a custom cut of AR glass that won't suck the life out of my checking account or output beam power?

(3.) Taming fat 635nm beams -
I'm still thinking about putting that 660/635 dichro to use, and I realize the 635nm beam is going to be WAY bigger. For those other folks using 635nm lasers - do you use a "pinhole mask" or something similar to cut the beam width down a bit, or just live with the "laser flab" falling off the sides of the scanner mirrors?

Thanks!!

[Anthony]

OK -

(2.) Custom AR glass -
My RGB projector case aperture would require a 2" x 6" piece of glass to seal the opening (oversized aperture for "expansion plans"...). Any recommendations for a source for a custom cut of AR glass that won't suck the life out of my checking account or output beam power?

Bridge/Laserwave should be able to suplly you AR coated glass.
I don't know what sizes he can supply and if he still offers the glass.

[allthatwhichis]

I use a mask for my 635. I cannot stand seeing the photons missing the mirror. I am losing those photons, but would be wasting the either way. There for a while, I was "slicing" some of the 635 away by knife edging a mirror into the beam to reflect what I would usually mask into a different direction and use it as you would a "waste" beam; grating, or other beam effects from another device.

[dsli_jon]

Hey Randy -

OK -
A few questions here for those folks who have completed a projector or two:

(1.) For those who move their projectors a lot -
Once you have found the "sweet spot" for your optics alignment, do you use anything (thread seal, etc.) on the optics adjustment and mounting hardware, or is periodic realignment just one of those "annoyances" you learn to live with?

For builds, I usually use 'blue' threadlocker (locktite, etc) cause you can move it later w/o too much heat - holds pretty good for most apps - but if you have a 'projector cover', make sure you let the system run - including projecting constant graphics - (so galvos / amps are kicking out the 'typical' amount of heat they would in a show) and once good-and-warmed-up (ie - running a couple healthy hours) then pull your cover, tweek, if needed, and lock-it down, replace cover (keep running) and pull cover / tweek as-needed, till the goo is dry...

Of course, that depends on the 'beefitude' of your adjusters, too - if they are thick, heavy mounts vs thin, 'bargain' mounts, you'll have less thermal-drift, even if you ie: do a gig in a 'hot nightclub', etc...

(2.) Custom AR glass -
My RGB projector case aperture would require a 2" x 6" piece of glass to seal the opening (oversized aperture for "expansion plans"...). Any recommendations for a source for a custom cut of AR glass that won't suck the life out of my checking account or output beam power?[/quote]

This stuff is the best we've found http://www.edmundoptics.com/onlineca...productID=1919

Extremely-low loss... (same coating used on most computer monitors...) What we do is, buy the 8" x 10" and cut-to-size. If you have a good, experienced glass-shop in town - even a picture-framing place - they usually have the pro-grade diamond-tip cutters, and will cut you up whatever you want...

But if you go that route - TIP: DON'T remove the blue-coating it ships with, TILL cut / ready to mount in your box - just draw the 'snap line' on the blue plastic coating with a fine-point 'sharpie', and CAREFULLY (so as not to scratch the glass, though it is pretty tough..) cut a strip out of the blue coating with an x-acto, strip it away, and tell the glass cutter to cut INSIDE that little 'bare' strip (line-width should be between 1/32" - 1/16")

This way, you protect the rest of your window, and keep 'hard-to-remove' fingerprints off...Cleaning is best done with slightly-soapy (ie dishsoap) water and a soft, lintless cloth OR an ammonia-based cleaner (ie windex) + water vs Acetone / Methanol (both leave streakies...)

Of course, you can also 'DIY' with a nice, new glass cutter, but TIP: get some 'practice glass' and the secret to a good 'glass snap' is confidence (ONE-stroke cut; ONE snap) and correctly-placed, firm, even pressure along the entire snap-edge.. but for such a 'narrow' piece it might just-as-well be worth a trip to the glass-shop, where they'll have a nice 'pro cutter' / table...

(3.) Taming fat 635nm beams[/quote]

If you have the money to invest in some optics, you'd be surprised the magic you can achieve, if it's really bad - if not, your pinhole / sweet-spot or MechEngs great idea of using the 'slop' for other fx is prolly the simplest...

Hope this helps...
peace..
j

[buffo]

OneStopLaserShop.com sells AR glass, and they will cut it to fit. Give Amanda or Fred a call and they'll hook you up. (Mention PhotonLexicon and they'll give you 10% off, btw.)

As for the thread locking compound, I've *never* had a need to put that on my optics. They don't move that much. My projector has been transported over a dozen times in the back of my Jeep, and the alignment never changes. (Randy, you know what a heap my Jeep is... You can just imagine how it rides... Like a tank!)

Adam

[Stuka]

Good info & ideas - thanks guys!!

Randy