Advive about knife edging after cylinder correction

[LaNeK779]

I suspect the red line mentioned by LaNek779 is from the wings of the P73 reflecting off the inside of the motor shaft. You won't want to add the complexity of a spatial filter before the shaft that will completely eliminate them, but you should see what a good anti reflection, black ink inside the shaft will do.

I will have to disagree. I had similar pronounced wings off of g73 diodes when I had glued the lenses facing the wrong way. When the lens was placed the way it was intended, those wings were much less pronounced. Moreover, in the above pic the beams do not go through the shaft (which is already spark eroded as kit said). Anyway, i am just winding Kit up a bit, knowing what a perfectionist he is most probably these wings are just emphasised due to the overexposed picture

wayne good news mate! congrats!
but with all that travelling when will you be able to put in a solid day's work?

[planters]

I will have to disagree. I had similar pronounced wings off of g73 diodes when I had glued the lenses facing the wrong way. When the lens was placed the way it was intended, those wings were much less pronounced.

I don't disagree with that. Do the lens the right way. Is the far field thru the shaft or not? He says it is, but then why image #3?

[badger1666]

Hey that last drawing of your revised setup
Is that knife over ? Cant tell , it needs to be

[LaNeK779]

Hey that last drawing of your revised setup
Is that knife over ? Cant tell , it needs to be

ooops.. i failed to spot that. badger is correct, the correction with a single cyl pair will not work with a knife edge setup
the beam needs to hit the cyls dead center, so with a knife edge one or both beams will be slightly off axis

[dnar]

You guys provide a world class (and free) design validation service!

[badger1666]

A 2.4mm spacer under one of the diode mounts will sort it for knife over.
Also make sure the distance from each diode to first cylinder lens is accurate to within 1mm
Of you will see a difference in each far field beam spot

ooops.. i failed to spot that. badger is correct, the correction with a single cyl pair will not work with a knife edge setup
the beam needs to hit the cyls dead center, so with a knife edge one or both beams will be slightly off axis

[kitatit]

Hi guys,
Thanks for all your ideas. I really have been up the back of the class when it comes to combining and correcting beams.

You have me doubting myself now... Chris you are messing with my head Was the shot taken through the shaft? I'm sure it was but I wouldn't put money on it now. I was rushing to get as much laser learning in as I could before I left home. I remember the wings still being there even when it was going through the shaft though. I think it was the wings that escaped before the beam entered the shaft as there was about 100mm from the entry to the motor shaft from the optics. It doesn't show up very well on that pic but on another shot you can see the silhouette of the motor body masking the wings then the wings start again out wider.

Yes the lens is in the right way. They are already glued in and can't go in the wrong way.

So it sounds like there is a consensus that I should stick with individual cylinders for each P73 like the first layout.

Badger, that sounds interesting. So if you lifted one of the diodes 2.4mm you would lift the right angled prism 2.4mm as well so the first beam travels under it and then you can have both beams hit the centre of the cylinder. Is that right?

I hear what you are saying guys, with only playing with one set of cylinders I did find being only a little off centre did create a big difference in the beam.

OK, so I'll go 2X(P73 diode, aspheric, cylinder concave, cylinder convex) then into the cube, bounce mirror then dichro?

For the blues, 2X( PLTB450 diode, aspheric) then into cube bounce mirror, then dichro.

Would I have to rotate one of the beam correction trains over on its side including rotation the diode 90 deg?

Should I add any extra or change position of bounce mirrors to make aligning the cube easier?

I'll draw up a new assembly tomorrow to show you guys.

Wayne, haha, it was extremely low key. Cindee and i got back from our Vietnam holiday on NYE and I wanted to go do something but the sheriff wasn't keen so I set up the projector in Cindee's back yard and put on a show for us and her brothers and sister... big budget show with a lot of planning

Thanks a lot guys for helping me understand this. Sorry to be a flake and be asking so many questions without doing much hands on experiments. Drawing pictures is all I can do when I'm away from home.

Hopefully others can learn from the thread too.

Cheers
Kit

[badger1666]

Hey kit i would lift the the mount behind the prism so it came
Over top of it and you end up with two beam stacked on top of each other
Or you can put it under the prism makes no difference
As long as they are each are the same distance from the first
Cylinder lens ( important ) and be after correction will look like =
I have a 3.8w quad p73 build like this in my
10w rgb

[kitatit]

3.8W quad?!!! 10W!! Yikes. That's some weapons grade fun right there

That sounds good.

If the beams are =, won't the sides be too wide to fit on the Plano concave?

What do you think the benefits of this way are badger? It obviously eliminates a set of cylinders. Do yo set the cylinders so they are square then move the diodes and knife edge optics to suite?

Any disadvantages?

[andy_con]

as chris has said two 500mw 638 like this = is the way forward. sit the cylindrical lens nice and close to the diode output and the beam will fit perfect