Modifying SC31 pro (and FC11) with different LEDs + TIRs

LED Flashlights – General Info 18650 Flashlights
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I have 2 SC31 pros and a FC11 that I modified. I used 519As from Convoy, standard and shaved. I had already ditched the horrible LH351D in the FC11 long ago then recently when I got 2 new SC31 pros I replaced the SST40s with 519As and the reflectors with TIRs. I have some TIRs from 2021 optics store on Aliexpress, and from Convoy.

Here is the build of the SC31 pro:

Sc31pro:
parts in order: plastic ring - lens - o-ring - reflector - gasket - MCPCB SST40:

reflector + gasket: 10.50 mm
lens: 1.50 mm
plastic ring: 0.32mm
total of these: 12.32mm

MCPCB with SST40: 1.52mm
o-ring: 1.5mm

Now to the modification:
MCPCB 519A Convoy: 1.51mm

3535 TIR Convoy (I checked various of the 25,38,60 deg TIRs that I have): ca.12.78 - 12.95 mm high

Options:

  1. remove plastic ring + lens, keep the o-ring of 1.5mm: file off 0.50mm from the optic although that slightly changes the pattern. Don’t file off more because then you get a dark section in the middle and the beam pattern becomes far wider.

2. remove the plastic ring + lens and replace the o-ring with a 21mm x 1.0 mm o-ring which gives a possible height for the TIR of: 10.50+1.50+0.32+0.5+0.01 = 12.83 mm
close enough, no need to file anything…

I got some 1.00 mm lens o-rings from an old S2+ and another pocket lamp, but will order new ones. I can then use the Convoy optics without modifying them and the bezel screws on completely as before.

I also used the optics from 2021 optics store which are less high, ca. 10.55 - 11.15 mm, which gives options such as keeping the lens to protect the optic, but that is not very important as optics are not expensive. These optics always seemed dimmer to me than the similar beam angle Convoy optics. Testing with the FC11 and SC31 pro and switching optics without using the bezel, I noticed that the optics from Convoy shine a little bit of light backwards, but those from 2021 optics store far more. The beam pattern might be a bit different but I think these optics also lose a fair amount of light into the housing of the light. Has anyone done testing of the efficiency of optics?

6 Thanks
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Addition: I used 2 frosted flat TIRs from Convoy and these also lose quite a bit of light. I don’t see any use of these over the pebbled TIRs. Note that I have not tried clear TIRs yet. As of now my suggestion for those wanting to experiment is first try a few Pebbled TIRs from Convoy (20mm diamater) from 10-45 degrees, an a possibly a few clear TIRs.

Further I forgot to note about the recess for the O-ring, but these are about the same height in the reflector as in the TIR on top so in the calculation of height it doesn’t affect the comparison.

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From personal experience - the flat/frosted TIR’s from Simon generally result in unpleasant beams. This is of course subject to personal preference, but I noticed distracting artifacting, that were even noticeable when used at a distance (in particular with the narrower spot lenses such as the 10°). Personally I wouldn’t consider the flat TIR’s at all. The beaded TIR’s are excellent - producing even beams edge-to-edge, with pleasant soft edges and almost no noticeable artifacting.

I use a 45° beaded on the SC31Pro and I find it quite a useful beamshape.

Over the years I have also transitioned to having a preference for TIR lenses over traditional reflectors. I realize now that I dislike the hotspot+spill beamshape.

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I just realized I’ve been doing the same. Every enthusiast should have a box full of varios TIRs. They not only allow you to select whatever beam profile you like, but they also can do wonders for eliminating tint shift with certain LEDs you might see with a reflector.

3 Thanks
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With the frosted 15 and 30 degree TIRs I don’t notice artefacts, at least with a SST20 in the FC11. For me the issue is too much loss of light and I don’t find the light distribution as useful as that of the pebbled TIRs.