Centering Optics on HDs

[darkzero]

I know this question has came up a million times but I still haven't found an answer if there is one other than super gluing.

As you all know centering Fraen-LP optics are a real PITA. I've got a McLux that I'm trying to center the Fraen over the HD but man I guess it just don't like me. I can center it by hand but once I try to get it centered with the bezel screwed on, the dreaded square and off center circle haunts me. /ubbthreads/images/graemlins/frown.gif

Also, I've see some beamshots of Fraen-LPs and they appear to have a nice round "hotspot". Or is the square sidespill part just not seen by the camera? When I center mine in my MagAA or the McLux (without bezel) I always get a square with a circle in it. Are the Fraens supposed to be spaced out from the emitter? If yes, by how much?

Any help, suggestions, comments, theorys, etc. with methods aiding in centering the Fraen-LPs is very much appreciated.
I need /ubbthreads/images/graemlins/help.gif /ubbthreads/images/graemlins/help.gif /ubbthreads/images/graemlins/help.gif. This is starting to making my hair turn white if I don't pull it all out first!

Thx

 

[TheFire]

Well, when I do the Fraen LP in the Arc LS, there is a combo of square and hot spot. I center the hotspot in there by moving the led in the direction the hotspot needs to go in order to be in the center of the square. In the Arc, the optic is sitting pressed right up against the emitter. Hope that helps at least some...

Paul

 

[MR Bulk]

If you use Krazy Glue (gel, not liquid) and let a fan blow across the whole thing as you are applying and then centering, it will stay in place when set and the nasty cyanoacrylate fumes won't etch up the optic surface.

 

[Bandgap]

Fraen makes a little plastic collar for this job.

Try your supplier

From Fraen's data sheet:

LENSES FOR LAMBERTIAN LEDs:
Ring Spacer allows to couple lens
to Lambertian LEDs without the
holder.

I don't know the part number.

Steve

 

[pedalinbob]

thanks for the info.

anyone researching this???

Bob

 

[Otokoyama]

You might take a close look at your LED. Is the phosphor square perfectly centered within the dome? Even with an optic or reflector perfectly centered around the dome, you can't expect the projected square to be perfectly centered around the hotspot unless its source is perfectly centered within the dome.

I suspect you can either adjust for a hotspot centered within the projected square or for the most tightly collimated hotspot, but not both.

 

[MR Bulk]

Paul, exactly. Which is why I'm thinking that even if a bezel could made to exactly center the Fraen over an also-centered Luxeon, the Luxeon itself might have a misapplied die...

 

[Otokoyama]

The effect seems magnified when using a 30mm optic (instead of a Fraen) over an HD, though the projected square in this case is relatively faint compared to the hotspot.

It's one of those "Luxeon lottery" things that we've just got to accept. At least the white color seems fairly consistent these days.

I very much like the Fraen beam for 30 feet or less (efficient and small), but the "orange peel" reflector seems to cure a whole host of beam production issues.

 

[Chop]

In my quest for the perfectly centered HD, I made a jig of sorts that holds a star so that I can turn it down to fit perfectly inside of a KL1.

It was a waste of time. The best thing to do is to eyeball it was trimming by hand and make adjustments as needed. All I can say on this issue is, "I love reflectors!"

 

[darkzero]

[ QUOTE ]
Bandgap said:
Fraen makes a little plastic collar for this job.

Try your supplier

From Fraen's data sheet:

LENSES FOR LAMBERTIAN LEDs:
Ring Spacer allows to couple lens
to Lambertian LEDs without the
holder.

I don't know the part number.

Steve

[/ QUOTE ]

I've never heard about this ring before. Seems like they would be helpful. I can't seem to find any info on these around here. By chance is there more you can tell me? Do you have one/any? Pics?
thx


[ QUOTE ]
Otokoyama said:
You might take a close look at your LED. Is the phosphor square perfectly centered within the dome? Even with an optic or reflector perfectly centered around the dome, you can't expect the projected square to be perfectly centered around the hotspot unless its source is perfectly centered within the dome.


[/ QUOTE ]

I remember reading about this issue right about when the Fraen-LPs came out. I never really noticed how off center some luxeons were untill reading about the issue. Since then I've been splitting my luxeons into two groups. Those that look close enough to the center for use with optics and those off center to use with reflectors. I just looked at the one I'm having trouble with and it seems to be off just a tad, so little it's hard to tell. Maybe I didn't notice it before of maybe I didn't think being this much off center would affect it's centering with the optics but I guess so. (I built this one some time ago and have been using a McFlood) I can get it centered with the bezel off but when I screw the bezel on no matter what I do I can't keep it centered. I'm suspecting that maybe the luxeon is not level with the Mclux head, slanting to one side?? I guess the best way for this one is to glue it.
thx

 

[Bandgap]

I have the Fraen data sheet.
Can anyone stick it on this site for me?

Steve

 

[Slick]

I found an easy way to center my optics - this is straight outta my bag of modding tricks...

When I make the final assembly, I use a generous coat of silicone dielectric on the o-ring that fits between the bezel and the lens. I find the center of the optic by pointing the light at the ceiling with the bezel slightly loose and tapping on it. With center located, I push down on the lens with my finger while tightening the bezel.

The lube on the o-ring permits the lens and optic not to spin when the bezel is tightened and reliably yeilds good results for me! Now days, I often times nail the perfect focus on the first try. Check it out. /ubbthreads/images/graemlins/wink.gif

 

[MR Bulk]

Hay Slick,

As usual, you Da Man. Glad to see you posting!

(nice avatar too, as in one who has held his beer a little too long...)

 

[darkzero]

[ QUOTE ]
Slick said:
I found an easy way to center my optics - this is straight outta my bag of modding tricks...

When I make the final assembly, I use a generous coat of silicone dielectric on the o-ring that fits between the bezel and the lens. I find the center of the optic by pointing the light at the ceiling with the bezel slightly loose and tapping on it. With center located, I push down on the lens with my finger while tightening the bezel.

The lube on the o-ring permits the lens and optic not to spin when the bezel is tightened and reliably yeilds good results for me! Now days, I often times nail the perfect focus on the first try. Check it out. /ubbthreads/images/graemlins/wink.gif

[/ QUOTE ]

Slick, you method is slick. Tried it and it does work beautifully.
thx!