Who want's to help design a real MONSTER?

[DMills]

Been contemplating having a go, time is the issue.

1: Don't use copper, the heat load is just not that great and copper is a bugger to machine. A good grade of aluminium should be quite sufficient.

2: Rigidity will be king, so I would avoid peltier cooling (which in any case just increases the total heat load (and temperature differentials)), a big heatsink in a separate compartment from the optics with a blower is IMHO a better approach.

3: Fast axis correction, try to use optics sufficiently large to handle multiple beams, and maybe collimate the slow axis right at the diode then follow with the fast axis anamorphic telescope.

4: You might wish to investigate rod lenses installed across the front of the array.

5: "Design and mounting of prisims and small mirrors in optical instruments" (Paul R. Yoder) has an interesting drawing of a single element anamorphic prism that works by TIR.

6: The diode emitter is a line, use this when you plan the optical layout.

7: If doing a 3 *4 array or such, design the mounting so you can knife edge multiple diodes off one mirror, it means you need two mirror arrays (a 3 and a 4 mirror group) but that is better then 12 individual mirrors.

8: Think carefully about what needs to be adjustable, not everything on the optical bed does and if it doesn't then machining a small alignment step and just epoxying the thing in place is one less thing to slip out of trim. Get a good book on the kinematics of machines, it will provide enlightenment.

9: At this power level, be careful out there, even diffuse reflections are dangerous, anodise black and cover all the optical path you are not actively working on (There may be something to be said for totally enclosed beam paths with O rings at the optics in the manner of a vag burner optical plate).

10: This is at least a grands worth of fiddle on top of the obvious parts (even if you are not counting your time), so maybe a five grand or so worth of light source by the time you build all the prototype sub assemblies.

Regards, Dan.

[Laserman532]

i find it rather humerus that people have 24 stuck in their skulls because that is what came with the projector. why not 8 or 12 or 36 or 48...people be funny that way.

and Dmills - 5k sounds like more in the ballpark if you place ANY value on your time.

I'll ask again...has anyone measured the output of the lightpipe with a power meter. I dont have one or that would have been the first thing that I measured.

[DjHeadie]

I know what Floyd does, I went and visited him a couple years back and he had me driving his boat around while we were whale watching... That's when he told me that he had a way to combine 100 plus 50 watt yags together into 1 beam.... I have a call into him and I think he'll at least help me with the design... Anywho, i already have my own idea of how to make it all into about a nickel size beam... so the race is on!!! VROOM VROOM!!!

christ! hope that works for you

[andy_con]

7: If doing a 3 *4 array or such, design the mounting so you can knife edge multiple diodes off one mirror, it means you need two mirror arrays (a 3 and a 4 mirror group) but that is better then 12 individual mirrors.

having an adjustable mirror mount for each diode is require, you wont be able to align properly otherwise

[DMills]

having an adjustable mirror mount for each diode is require, you wont be able to align properly otherwise

Depends on how you do it.

Expand the beams from the individual diodes to 10mm or so, knife edge them (giving say a 50mm composite beam) then stick them through a telescope. The divergence coming out of the scope will be (to a first order) no worse then the divergence before the beam expanders, and mechanical tolerances don't scale with beam diameter.....

It means you need two conventional lenses plus the anamorphic stuff per diode plus the rather large telescope lenses (Maybe 50% or so efficient overall if everything is AR).

Regards, Dan.

[andy_con]

Depends on how you do it.

Expand the beams from the individual diodes to 10mm or so, knife edge them (giving say a 50mm composite beam) then stick them through a telescope. The divergence coming out of the scope will be (to a first order) no worse then the divergence before the beam expanders, and mechanical tolerances don't scale with beam diameter.....

It means you need two conventional lenses plus the anamorphic stuff per diode plus the rather large telescope lenses (Maybe 50% or so efficient overall if everything is AR).

Regards, Dan.

but how will you adjust the beams to be on top of each other at distance if they are not adjustable?

[DMills]

Ok, consider an array of say 4 * 3 diodes firing downwards for the sake of argument (there is method in that as you need to change direction twice to make this work), below the diodes are the lenses (probably fitted into the same hunk of ally), and below them are 3 horizontal mirrors mounted on adjustable mounts. If these mirrors span the long axis of the diode array you will get a horizontal beam consisting of 4 stripes of light spaced the same as the diode spacing, but with the 3 diodes now stacked reasonably tightly.

4 more knife mirrors and you have a rectangular beam ready to telescope back down to fit the scanner mirrors.

The key to making it work is that the initial axis of each diodes output beam must be parallel, but I am guessing that the diodes themselves are acceptably close and it is a question of machining tolerance in the mounting block. Push comes to shove make each diode mount individual, but there are reasons to avoid that if possible.

Definitely needs someone good with a milling machine (All the surfaces will have to be machined flat, stock plate will not cut it).

This thing will always have a big ragged beam, this is not a holography source.

Regards, Dan.

[MechEng3]

I don't understand having trouble machinig copper....no sweat...CNC is flooded with coolant and it just eats away. I trash any suspect or possibly dull tooling though. Saves time in the long run.,,and provides smooth milling with heat away in the chips. I won't build one of these without TEC cooling....all 3 of mine are doing great.

[Laserman532]

I don't understand having trouble machinig copper....no sweat...CNC is flooded with coolant and it just eats away. I trash any suspect or possibly dull tooling though. Saves time in the long run.,,and provides smooth milling with heat away in the chips. I won't build one of these without TEC cooling....all 3 of mine are doing great.

you have 3 running 24 diode systems????!!!!!!!!!!!!!!!!!!!!!!!!!

[slicklasers]

I spoke with Floyd and he gave me a few tips, but said I was on the same path he would take on this project.... I will let you all know when I get the solidworks design done.... as for TEC cooling, I might decide to add it depending on how warm it gets....