BLF recoil über-thrower

Hi all,

I have this idea:

(updated re-upload)

Some of it has been discussed here:

[PART 1] Official BLF GT Group Buy thread. Group buy officially closed! Lights shipping. - #362 by Jerommel (and on)

but i don’t want to hijack that topic any further, so here’s the dedicated topic.

I made some drawings to illustrate things:

compared to a normal reflector:

A recoil seems (to me) be better in many ways.
The light straight from the LED (0°) only hits a small area, which is what you want because there’s not much of it, as you can see by the radiation diagram (blue).
You can see with a normal reflector much more light comes from the middle of the reflector, and when you want to reflect the rays at more than 45° from the emitter, you need to add a LOT of depth.
This is also true for the recoil reflector, but that adds more to the diameter.
It therefore seems pointless to me to make a recoil reflect more than 130°.
Even 120° seems good enough, but with an extra 10° you get just a bigger slice of the pie (the radiation diagram).
What i like about the recoil set up is that the focal distances (from emitter to reflector) don’t differ too much from eachother.
So it will have less of a corona with a different tint than the centre.
I was thinking about a 4 or 5 inch / 100 or 125mm diameter reflector.

As usual a domeless LED will produce a tighter beam than one with dome, so i think an XP-L HI 0r XHP35 HI is the obvious choice.

I would love to see this take form and be produced, but for now we can discuss the concept.

Shoot! :slight_smile:

(no idea what for, but they all do this :smiley: )

I would make the whole center component out of copper… :+1:

As said in the other thread, I’m building a concept light one of these days. First experiments show that the throw/diameter is similar to a common reflector or aspheric lens flashlight, which is pretty good I think.

I think that is what he designed it to be. I don’t believe it would have to be 100% copper, though. Just the part behind the LED, maybe 5mm thick or so should benefit from being copper, and the rest could be aluminum. The reason is that as the heat travels out from the point of contact at the LED, it has an increasingly larger area to flow through. So, the thermal resistance will shrink as you get away from the LED, just from that fact. Then again, it would be simpler to just make it full copper. In the other thread, it was also mentioned that “3 fins forming a ‘Mercedes star’ would look cool too”. :wink:

I thought a a recoil would give higher cd/mm. Isn’t that the point? If it’s the same as a traditional reflector, what makes it worth it?

Perhaps that is one one the reasons why there are no recoil flashlights on the market? But as I said, a very first experiment, nothing optimised. What would make it worth is that a big reflector weighs much less than a big aspheric lens, My 1405 is one hefty thing, and I would not want to go bigger. But in recoil form I can go bigger and it would still weigh nothing but does provide a spill-less beam, what a normal reflector light can’t do.

I do like the beam profile form a recoil, just the thermal issues have kept me away from trying to make one.

It would have the same relation between throw and area as a normal reflector. A potential advantage is that it could be made to gather near 100% of the light into the beam. However, as I was explaining in the other thread, the increase in light collection won’t be large because standard reflectors are already pretty good at this.

For example, a C8 reflector, with depth=32mm and reflecting diameter=38mm, collects 74% of the light (lumens) into the beam. Only 26% escapes as spill.

Interesting project!!

You’ll find that reserved post handy down the road
Notes: updates in the OP do not give a thread that red “update” flag or put it back on top (so ideal for interest list and such)
You can PM 10 people at the time, a reply from one of those will be send to all.

Well there’s more than none on the market. A search turned up this one, for instance. I’m not saying its a good light, only that it is out there. This idea has been tried before, just not to great effect.

Sold out, like the good old Ultrafire UF-007. It was an interesting light but not worked out as well as could be done (pretty low-driven XR-E led).

I’m in for one of these.

I have one of those budget recoil throwers. It certainly had potential, but didn’t deliver in stock form. And despite several attempts at modding it I’ve got nowhere with it. But a well designed one from the ground up would be a pretty cool addition to the collection.

Have this one:
(from AliExpress Android)

Where did you get a parabolic reflector?
Or do you have a spherical hollow reflector?
Anyway, keep us posted.

That one has an even smaller reflector (pure waste of head size!) than the original UF-007 !

Copper LED support must be like Mersedes label star.

That’s crazy cheap…
I have this one:

It seems the original has a larger mirror / the cheap one has a tiny mirror in it.
And the mirror in the original one is already small and shallow, it only picks up less than 60°
[edit] no, it seems to catch 90° of the LED light[/edit]
of the emitter light, and then it’s hindered by that big XR-E…
It does throw well though, very tight beam, but i have always found it a frustrating and inefficient design.
I think the mirror is spherical by the way, but you don’t notice that when you only use < 60° [edit]that’s 90°[/edit]
I’m planning to mod it one day, replace the boom / holder and put an XP-E2 or maybe an XP-C in it, but again, i can’t find parabolic mirrors, would have to use original mirror.

This seems to be the thing that discourages folks.
But i think that with a copper boom / arm / LED holder, on which the thermal slug of the LED is soldered directly, will suffice.
In my drawing it may be too thin a fin perhaps, although i think 2mm wide will do the job, both as a thermal path and as a sturdy holder.

The “Mercedes star” would look great though, but maybe a fin across the whole diameter would be best, fitting in 2 slots in the head, centring and focusing easier / more reliable and exact in production of the light.

Been waiting for you to start a thread on this. Really sounds exciting.

I used to have a 6 inch reflector telescope that I gave to a friend to give to their kid for Christmas. My understanding is that the kid only tried to use it once. I wasn't aware of recoil lights back then. A soon as I learned about recoils, I regretted gifting it. It was one of those lower-end Tasco telescopes, but I bet it would have worked great.