I have made some progress.
First though, I noticed a couple of problems. The optic legs stick through the mcpcb, so the optic did not seat fully. I thought this was a problem so I sanded the legs shorter so nothing protruded. I am currently not sure if I did the right thing. I has not used a KD triple mcpcb with one of their optics before.
The next issue was that the optic would still not seat fully. Close inspection revealed the portion of the optic that fits over the emmitter did not go as low as it would if the optic was used over a Cree XP-E triple. This project is using the LH351D Samsung. I pondered wheyher or not to slice the domes or to modify the optic, reaming out the “socket” a little. I elected to mod the optic. I used two different sizes of number bits and carefully turned them just using my fingers. I removed just enough material to allow the optic to seat fwith the three legs down against the mcpcb. I also considered drilling clearance holes in the copper disc.
I have not yet wired up the led to check the beam. Hopefully I did not ruin it.
So that was one issue. The other thing I oticed was that I had a slight concentricity problem between the mcpcb and the heat sink as well as with the copper disc that is mounted between the mcpcb and heatsink. The runout was not great but was enough to create possible problems with the next step.
I has a spare copper disc and a spare heatsink though. So I decided to redo this portion of the head assembly.
This time I used a different approach. I first found the center of the copper disc. Then drilled a center hole that matched the diamter of the center hole that the factory made in the mcpcb. I used that drilled disc to determine the point to drill through the heatsink center. The result was just about as perfect as could be when using the tools at hand.
The next issue to correct ws my chosen method of fastening the mcpcb to the copper disc. The previous method relied on using a pait of factory holes in the extrusion that were close to, but not perfectly matched to the notches in the mxpcb. Instead of doing that all over I decided to use the two smaller holes in the mcpcb. The pencil point in the next image indicates the hole pair I mean.
I used a machine screw to secure the mcpcb to the copper disc and heatsink.
I then drilled a clearance hole in the support wood block and proceeded to drill a dimple in the copper plate, using the holes in the mcpcb as a template.
I just barely marked the copper using the drill press. Then disassembled the three pieces and drilled a #50 hole through the copper for the 2 mounting screws.
The holes were hand tapped with a 2-56 thread.
The mcpcb is secured with two 2-56 pan head machine screws.
The heat sink does not have sufficient solid metal in the central area to tap into the aluminum body of the heat sink. The two screws penetrate the copper disc and protrude into a pair of the extruded voids.
Now I am happier with the mcpcb, copper disc and heatsink assembly and am ready for the next section. That’s coming up in the next post.