Often, when someone builds their first light, it’s a P60. There seems to be a common problem when using an orange peel reflector.
I have some cut-a-away photos that may help.
This photo shows the difference in the construction of a common orange peel and smooth reflector. The area just next to the threads is for solder/wire clearance. I call the area around the emitter opening the ‘pressure plate’. Notice that the orange peel reflector has a much larger pressure plate and therefore, a much smaller solder/wire clearance area.
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The lack of clearance for the solder joint is usually a problem because the reflector can short out the solder joint. In this photo, you will see that with the threads engaged less than 2 turns, it’s creating a short.
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One solution is to use an isolation pad that completely covers the solder and wires. The problem with this… you will not be able to properly focus the reflector. Also, if less than 2 threads are engaged, the thermal transfer will be miserable. Using the full sized isolation disk means the pressure plate on the orange peel reflector will be raised up the thickness of the solder joints or wires (whichever is thicker) plus the thickness of the isolation pad.
My solution is to partially machine the pressure plate so there is room for the solder and wires without the risk of shorting. This also allows for more thread engagement.
There are two solutions for the builder doesn’t have access to a lathe:
If you’re good with a Dremel, grind some of the pressure plate off… be sure to mask the emitter opening to keep the inside of the reflector clean. In the next photo, the red line shows what I machine off. I really needed to create these cut-a-away reflectors to decide how much I could take off. You should be able to use the photos to decide what is a safe amount to remove.
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Probably the easiest solution is to use a smooth reflector. There is much more clearance for the solder and wires and you can screw the reflector down far enough to focus it.
Removing part of the orange peel pressure plate or using a smooth reflector will allow better thermal transfer, better focus and larger lead wires.
Might it just be brand-to-brand variation? Or XM vs XP reflectors? Made for a -HI variant (ie, to allow the emitter to sit deeper in the reflector)?
I mainly (ie, always, so far) got/used SMO reflectors, and got some MOP on order (slow-boat from Chiny, so might be a coupla more weeks ). Will see/compare when I get ’em.
Wow. Thank you for that. I have had a Solarforce host for months waiting for me to have the time to build properly. I will keep an eye on this for sure.
Both of these reflectors are XM. I have seen a model of reflector that had a different plate, but it was almost flat on the bottom, low quality and virtually unusable.
The XM reflectors shown are the ones you would get from RMM, International Outdoor, Fastech and KAI. The Fastech and KAI seem lower quality, but still the same design.
I haven’t found a P60 reflector made specifically for them XPL HI. With the XPL or XPL HI, you can use the XM reflector with the appropriate isolation pad or the XP reflector.
The XP reflector will give you a little more throw, but also has more artifacts. I personally don’t think an orange peel is appropriate for a XPL HI.
Holding the two reflector halves together, there is a difference in geometry. The orange peel reflector tapers towards the emitter less at the bottom than the orange peel. You can see this in the pic with both reflectors…from the emitter opening to the lowest portion of the reflector on the smooth is ‘0’…on the orange peel, it’s about 1.5mm. This would cause the need for a wider plate at the bottom of the orange peel, but you can see in the cut-a-way, there’s still plenty of room to create more clearance for the wire and solder.
Yeah, I’ve got a half-dozen or so of those adapter rings just in case… would rather have a reflector made specifically for the emitter than try to shoehorn an XM into an XP and worry about focus, etc.
That’s what I was wondering. A parabola is a parabola, whether it’s a dish like a satellite antenna, or a deep skinny ‘U’-shaped cup. To keep the same diameter fixed, you can flatten/elongate the parabola (its “pointiness”, but the focal point shifts proportionately as well.
That’s why I was wondering if the wider/flatter one with the big “pressure plate” would be an elongated parabola with the pushed-back focal point, with the “hole” part of it shaved down to keep the same length to accommodate a -HI (or dedomed) emitter. And the regular tapered pointy one being the regular shape (and normally-situated focal point) for a regular XM.
The wide variations in P60 reflectors makes proper fitment difficult. You can still find reflectors made for XRE and SSC P7 emitters w/ large cut outs and both wide and narrow bases. Some early XPE/G reflectors have very small opening for just the emitter dome and a flat base.
My only suggestion is to make the solder connections as thin and flat as possible, solder as far to the outside of the MCPCB as possible and use Kapton tape to insulate.
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). Will see/compare when I get ’em.