I put a FFL707a in my M21F. Love it but there’s a bit of a donut hole…

Flashlight Modding and DIY Parts
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Hey Y’all.
I did my first reflow! I swapped the XHP70.3 HI 4000k on my M21F out for an FFL707A 4000k. I used Lumencraft-Matt’s excellent tutorial as a reference, and it worked perfectly on the first go. Thanks for that well put together video!

I love the color and tint of the FFL707A. It’s actually less rosy than I expected. Just a very nice comforting gentle rosy. It feels very clean and I believe will really excel outside. I dont have an XHP70.3 HI to compare with any more, but it feels just as bright.
The only problem is there is a slight donut hole in the middle, more noticeable at low levels. Because this was my first reflow, I ended up getting a little bit of flux on the emitter, and did my best to clean it off with a Que tip and alcohol. Could I have perhaps damaged the emitter by doing this? What would be the best way to get rid of the donut hole? Just accept it? Maybe get an M21H to put it in and keep a XHP70.3 in the M21F? it is more noticeable In Real Life than in the photos

And then, after I had it all back together I wanted to show my room mate “look what I did” and I accidentally dropped the glass lense when I unscrewed the bezel again… it shattered on the floor, Ugh! On convoy’s website it doesn’t list a specific lense for M21F, I’m assuming the M21H lens fits because they are both 40mm heads. Can anyone confirm that?

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Big ouch for that fat finger print on the reflector cup.

The glass lens has a different diameter to M21H so you will have to ask Simon specifically for M21F glass.

As for donut hole, you can try to put some shim under the gasket to rise the reflector up a bit and see if that makes it better.

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A lot of Perfectly Focused Lights will have that doughnut hole close-in, which makes perfect sense. Only light which hits the reflector gets thrown forward. When you look down the hole, you don’t see a circle of reflected area, but a ring. So only what hits that ring gets thrown forward, and close-in is also a ring.

Farther out, as “blurring” occurs, that hole in the middle eventually fills in.

All my tightest pencil-beam lights have either a hole or at least “tint-shifted” area in the middle close-in. Farther out, perfect beam.

Also, big chips like the XHPs will “blur” faster and closer.

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Ha, yea I only noticed that in the picture afterward… must have been when I dropped it…

Cool, I got sick right after that so I haven’t had a chance to test it more thoroughly… if it’s only a close in phenomenon I reckon I can live with it

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If you don’t mind sacrificing some throw you could try something like dc fix or similar diffusion film. It does wonders to blend the beam.