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Knife edge vs. PBS

chipdouglas

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Hello guys,

I'm gonna make a liquid sky for my campsite at burningman and am wonder what is the best way to do it.

I'm using 2-m140's. I have a 445nm PBS and a knife edge array from said projector. What would be better to use for combining the beams? :thanks:

Any help is greatly appreciated.

Michael.
 

daguin

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For your purpose, either will work fine
Choose the easiest for you

Peace,
dave
 

chipdouglas

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I've never done knife edge before, I've seen andycons website though. Since I have you, what would be better for bouncing the beam... A laser printer hex mirror or a spiro set up?

Michael
 

daguin

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I've never done knife edge before, I've seen andycons website though. Since I have you, what would be better for bouncing the beam... A laser printer hex mirror or a spiro set up?

Michael

Do you want a "cone" (spiro) or a "line" (hex) ?

Peace,
dave
 
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Bionic-Badger

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It'd probably be easier for you to power using a spiro setup, and you could add multiple controls/fan as needed. I've worked with a laser printer mirror and though they are really fast and stable, you need to get the power right, angle the laser towards the hex correctly, and also ensure that your beam is small enough to be fully reflected. The hex mirror also moves extremely fast, which is probably not needed for your setup.

I'd go with the PBS if you're using only two lasers. The knife-edge will require you to get them side-by-side which may affect the shape of the beam. The optics on the projector knife-edge array are also not precisely aligned because the projectors only needed a large mass of blue light, not a beam.
 
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There are a few ways to knife edge. Most commonly the diodes are side by side with 2 mirrors,
but this is not necessary. A single mirror used to reflect the 2nd beam and the other beam straight
through similar to what you would do combining a red and green, minus the dichro of course.

If you need to break loose one of the FS mirrors from the stock array, heat the back gently
then pop it off.
 
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Cyparagon

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Or skip the beam combining altogether and use two line generators. Place the lasers next to each other - the lines will overlap and appear as one. This is cheaper and probably easier to align.
 

hakzaw1

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Hi michael-- I HATE YOU!!!

BM has been on my 'bucket list', like, forever- now its hard to get tickets that are beyond my budget anyway
and the days when those bring lots with --to the table , i hear, no longer get anyone, any breaks.


I typed up a long bunch of ideas and solutions for your Lig. Sky/ Tunnel portable efxs but I got bumped of line ( yeah.. old hak is STILL only spending $9 a month for his dial-up ISP) so after maybe 45 mins of brillaint solutions i once again forgot to do all that in word and when I clicked -'submit' my work as gone.

so shorter version

Why knife edging? guess you want more than one 445 can make.

you could just put two on your mirror and get twin lines or cones-
I dont think the Kasio knife edge array is at all useful( I have tried)
better success would be gotten with one of the FS Mirrors in the Kasio optic train.
One beam, of course, needs to just slip by right next to one the hits the edge of the FSM.

and doing that may be hard with the Kasio knife edge array IMO
besides how will you get two diodes as close together as they are in the diode array HS ??
Solutions
for tunnel--
glue mirror onto plastic gear- glue or compression fit that onto DC motor shaft
(like a handheld personal battery fan)- affix to something( tripod/=- board) then affix laser allowing
you to adjust the angles.

Liq Sky--
Flat line- AixiZ offers a lenses for blank 12X30 modules - easy --

wavy line will be IMO much harder- or for me impossible.

my 1st Liq Sky was a PC fan- & thick FSM from thrown away flat bed scanner- cut to size & glued on its edge.

and mounted for allowing angle changes to make the line go where you want.
some will run all day on a single or pair of 3.7 vdc li-ions
to make the most 'whispyest' efx I remove the blades from these fans to avoid air moving any of my fog about.
I shut off all 'air movers' in my 'showroom'- a/c --fans - open windows etc.

a PC fan can also be used for tunnel efx- just glue one of the Kasio FSMs (from inside the optic train there are two nice thin ones) on the front and turn the fan on edge/side I dont worry much about how flat its mounted- as it seems to be impossible to glue it TOO flat.
But if you want your cone to go big quickly then a shim needs to go under one edge of the FSM --
Jeff K has a BM private Social Group-- he can 'screen' you to see if you can join us-(lol) he is an old BM vet( did lasers there a few yrs)- but you may already know that- WE expect a ton of pics to be posted when you get back- have a great time.

maybe when I hit the lottery I will make a BM-

len
 
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chipdouglas

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Thanks Hak!! i'm going to be running all this off of a generator so i don't need to worry about batteries.

Yeah, i'm stoked, we are going for my brothers 30th. This was the first year bm didn't have the ticket lottery. We got our tix for 380 each. and 9 of us are all chipping in for a nice rv.
 

hakzaw1

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^^^ according to Jeff that's the only way to go.
$380 sounds actually reasonable to me.

Hope the 'Man' does not get burned ahead of the planned time..

have a great BM--hak
 
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Something about line generator optics never seem quite 'right' to me. Just don't look as good as spinning mirrors.

As per above, just get a PC fan and glue a shaft mounted mirror to the hub, and away you go.
 
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Yep get a good balanced spinning mirror and you can shine as many lasers as you want at it.

You will want to put it in a enclosed box with a window just in case you don't know it's rather dusty there :D

What camp are you going to be in do you know yet ?









I burned the Man 3 years in a row 2000 to 2003 :D
 
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