Hey group, need some help finding a TIR. It’s for a Convoy H4 which also fits S21E optics. Needing a TIR with a 7070 hole instead of a 5050 hole. Below are the dimensions of the stock TIR. Any help is greatly appreciated. Thankyou!
The stock TIR doesn’t have a 5050 hole–a 5050 footprint has a diagonal (thus diameter) of around 7mm, so 5.70 as pictured would not do. It looks like the optic is not enveloping the footprint but sitting on top of it, so what matters is not footprint size but dome size (or size of light-emitting area). Thus if you use a 7070 domeless emitter (such as the XHP70.3HI) the stock optic should suffice–according to this test one can calculate the diagonal of the XHP70.3HI light-emitting surface to be around 5.4mm, which is less than (thus compatible with) the 5.70 as pictured.
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It’s a bit destructive trying to fit this optic over a 7070 footprint emitter as the optic will sit on top of the silicon surface of the emitter. If you screw down the frame / front glass then the optic can cut into the silicon layer and damage the emitter. For some emitter it might be fine. But I’ve seen instances where a damaged XHP50.3 HI emitter started to burn because of internal reflections of the damaged part.
The optic will be sitting on the silicone surface even for a 5050 emitter, so the same problem has always present. But excess pressure, as you pointed out, is something to keep in mind during assembly, as the latest XHPs are not as robust as the previous generations. Though at the same time the non-phosphor silicone shouldn’t matter that much, people used to “slice and dice” XHPs and remove that silicone with no issue.
To completely avoid sitting on top of the silicone would require the LED opening to have a 10mm diameter, which is gonna be a tough find if the entire optic is only 18mm in diameter.
TBH the most ideal solution would probably some sort of reflector or mule/hybrid reflector. A TIR that is barely larger than the underlying LED really hinders the transmission efficiency, as a lot of the light emitted won’t have the critical angle to achieve TIR.
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