Focusing the KL4

I just took apart my L4 (only got it yesterday), and had a thought but need some opinions from those of you who have opened up a KL4 before.

Obviously the emitter won't go further into the reflector without enlarging the reflector hole, but it seems that it is possible to move the emitter away from the reflector. The idea is to place thin washers or shims between the black heatsink and the reflector head.

However I did not have any washers of that size so I connected the circuit to some batteries and moved the heatsink slowly outwards by hand. The result was that the void in the center can be removed at the expense of it being slightly more flood than spot.... That's all I can come up with at the moment.

Maybe others can try this and make some comments?

-YC

YC,

I believe your assesment is sound. I have discovered when using the PM6 reflector that backing out the 5W HD LED's about .020" from what is likely the "true" focal point will remove the null. This has also been observed with some of the optics. A 1W HD in the KL4 reflector doesn't produce the null and again with the PM6 reflector, a 1W HD can be placed at the presumed focal point without the null. The surface tension of some thermal grease would presumably hold some thin washers on the heat sink face to aid in reassembly.

One concern might be the resultant seal of the two gaskets. It might be a good idea to then add a third gasket to make up for the gap induced in the seal from the washer stand off. Another more dificult solution would be to put a slight counter bore in the heat sink face to drop the LED back without changing the geometry of the rest of the component assembly.

- Don

How does the PM6 reflector compare to the L4 reflector size-wize? Can someone provide a side-by-side pic of just the reflectors?

The L4 reflector is integral to the head. The effective diameter is about 3/4". The PM6 reflector has an effective diameter of about 1 1/32".

- Don