Sealed Optical Housing - Ideas?

Has anyone implemented a "sealed" optical section on their projector yet? Ideally, some setup that would allow for beam height adjustments, keep dust off lasers, dichro & scanner optics, yet heatsinked sufficiently to avoid any problems?

Seems like I recall Dave & Aijii mentioning this for a projector some time back - sure would appreciate seeing any photos from those that may have done this already.

I had planned to use an optical breadboard, maybe wall off the lasers/optics and cap the unused holes? Possible heatsink to the underside, if needed.

Suggestions welcomed....

Greg

Drill and Tap aluminum board....so you don't have to plug anything.
Optics and lasers goes on one side PSes and Drivers on other. Fans are cooling lower compartment. Thats basically all to it.:D
But lasers have to be solidly attached to the board with aluminum spacers and thermo paste. (Arctic Silver for ex.).

google:

parframe
structural aluminum
slotted aluminum
slotted rail

thorlabs xframe

the slots in 1" slotted al rail exactly hold the .220" lexan you can get from a plastics shop.

Steve

you can also put the sealed part under positive pressure. that'll keep the dirt from getting in and help to cool your lasers/scanners. jsut get a small (new) car air filter and have a fan pulling air through it and blowing into the sealed part.

I've heard of hermetically sealing optics enclosures, but haven't seen an example of this in practice.

Otherwise, another tip I've received is to use one of these camera lenses for your beam aperture:
http://www.photonlexicon.com/forums/...1&d=1219254097

-Jonathan

I hear they work well.

-Jonathan

Quote:

---

Originally Posted by platinum

I've heard of hermetically sealing optics enclosures, but haven't seen an example of this in practice.

Otherwise, another tip I've received is to use one of these camera lenses for your beam aperture:
http://www.photonlexicon.com/forums/...1&d=1219254097

-Jonathan

I hear they work well.

-Jonathan

---

Jonathan / Platnium

I can highly recommend this filter, I use one on my projector

Jonathon have you checked out the gallery?

"Skylight 1B
Reduces the excessive bluishness that frequently occurs in outdoor color photography, especially in open shade under a clear, blue sky. The absorption peak is in the range which corresponds to the film's green spectrum. This means outstanding outdoor shots with superb color balance and clarity under all conditions. Also keeps skin tones free of colored reflections from nearby objects such as the shade of trees."

I wonder what they do to 405nm?

http://www.hoyafilter.com/products/hoya/coatings.html

Quote:

---

Originally Posted by dar303

"Skylight 1B
Reduces the excessive bluishness that frequently occurs in outdoor color photography, especially in open shade under a clear, blue sky. The absorption peak is in the range which corresponds to the film's green spectrum. This means outstanding outdoor shots with superb color balance and clarity under all conditions. Also keeps skin tones free of colored reflections from nearby objects such as the shade of trees."

I wonder what they do to 405nm?

http://www.hoyafilter.com/products/hoya/coatings.html

---

http://www.hoyafilter.com/products/h...es/005fig1.jpg

Looks like they can, although you might lose ~2% of light that low on the spectrum, according to this chart anyway.

Definitely go with the SMC option.


-Jonathan

Provided heat build up from the scanners isn't excessive, I can't see why in principle you couldn't have completely sealed optics.

Essentially I think you'd need a solid shell to fit over the optics area and fasten down hard onto the optics base plate and against the front wall including aperture (obviously the aperture would either have to be glass sealed or subject to the addition of a glass seal in the cover), (with a rubber edge seal if you really want to keep dust out) and then into the side / end of that shell you'd need windows (maybe skylight filters) to allow the beams from the lasers to shine inside to the dichros. I dare say there'd be slight loss but looking at the filter specs above, it would be small and would have to be balanced against losses that might be caused through dispersion by dust on the dichros / mirrors.

This is only an opinion though and is untried by me.

You can have complete sealed projectors, including the PSU's, laser, scanneramps, etc.

Just make sure the lasers/drivers/etc. don't have fans on them and the drivers are mounted at the heatsink-bottom. Heatsink can be actively cooled using a fan at the outside.

at the first uk laser meet mark (fluff) had a unit with sealed optics. said it worked very well

near the top

http://www.laser-man.co.uk/2006/inde...d=51&Itemid=71

hepa filters work good and are cheap from home heating uses and from car passenger compartment air filters these days.

Steve

Quote:

---

Originally Posted by mixedgas

hepa filters work good and are cheap from home heating uses and from car passenger compartment air filters these days.

Steve

---

What about vacuum cleaners? (the HEPA ones) Just a thought..

-Jonathan

adhesives they use suspended silver must be mixed prior to use, but you will get no lower thermal resistance figures anywhere this from a sworn user its the Xhit! Diematt has sent me samples they recommend (weird premix in a hotdog roller or keeping on dry ice from purchase to usage.

On sealed projectors I use a 2 inch or higher fined heatsink and mount laser galvo amps on it the fins are most efficient upward if you can but I have my optical table offset from case bottom and then forced air if possible get supplies in 3 rd space top and again open to convection cooling. In otherwards get a largeheatsink and use as optical table, fins down, if not flat since extruded I have taken to cnc machine shop or auto and have sand or machine milled flat. I hit junkyards big heatsinks are not always easy to find.

artic silver is good this stuff is leading edge if you are working with lots of heat producing equipment and need the best conductivity offered anywhere, check out Diematt.

Quote:

---

Originally Posted by Dr Laser

Drill and Tap aluminum board....so you don't have to plug anything.
Optics and lasers goes on one side PSes and Drivers on other. Fans are cooling lower compartment. Thats basically all to it.:D
But lasers have to be solidly attached to the board with aluminum spacers and thermo paste. (Arctic Silver for ex.).

---

Thanks - a lot of good suggestions here. I like the positive pressure w/filter idea...

Jonathan,

Thought the same - vacuum cleaner HEPA filters should be plentiful, readily available (cheap?) and in a variety of sizes.

Greg

Quote:

---

Originally Posted by Displaser

. . .Thought the same - vacuum cleaner HEPA filters should be plentiful, readily available (cheap?) and in a variety of sizes.

Greg

---

They come in little square sizes too, although mounting up a cylindrical one could be kind of neat too.

I think I originally got this idea from Lasernerd here on PL.

-Jonathan

artic silver is good this stuff is leading edge if you are working with lots of heat producing equipment and need the best conductivity offered anywhere, check out Diemat.

Quote:

---

Originally Posted by Dr Laser

artic silver is good this stuff is leading edge if you are working with lots of heat producing equipment and need the best conductivity offered anywhere, check out Diemat.

---

I always use this on my PC processors and its the dogs. :p

Keeps your processor a couple of degrees cooler than most other compounds. I'd certainly recommend it also.

Or just hook a 480$ dyson sweeper to your projector. No replacing the filter.

Sorry, couldnt resist.
I still can't belive people will pay700$ for a sweeper at the home depot.

Steve

Quote:

---

Originally Posted by mixedgas

Or just hook a 480$ dyson sweeper to your projector. No replacing the filter.
Sorry, couldnt resist.
I still can't belive people will pay700$ for a sweeper at the home depot.

---

Not to pull this thread too far off topic, but if you think $700 is expensive for a vacuum cleaner, then you've obviously never heard of the "Rainbow" vacuum cleaner. They were $700 back in 1990!!! (Don't know what they'd sell for these days; probably $1500 or more...)

Of course, they were also sold exclusively through multi-level marketing (think Amway), so now you know why they were so expensive...

People bought them though.:rolleyes: Probably are *still* buying them...:eek:

Adam