BLF recoil über-thrower

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Jerommel
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BLF recoil über-thrower

Hi all,

I have this idea:

(updated re-upload)

Some of it has been discussed here:

http://budgetlightforum.com/comment/1032516#comment-1032516 (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! Smile

Looking for:

5” parabolic reflector (for recoil light)

Edited by: Jerommel on 06/11/2017 - 17:19
Jerommel
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reserved
(no idea what for, but they all do this Big Smile )

Looking for:

5” parabolic reflector (for recoil light)

AlexGT
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I would make the whole center component out of copper… Thumbs Up

djozz
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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.

DavidEF
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AlexGT wrote:
I would make the whole center component out of copper… Thumbs Up

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

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pilotdog68
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djozz wrote:
First experiments show that the throw/diameter is similar to a common reflector or aspheric lens flashlight, which is pretty good I think.

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?

My Favorite Modded Lights: X6R, S8 , X2R , M6, SP03

Major Projects:  Illuminated Tailcap, TripleDown/TripleStack Driver

djozz
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pilotdog68 wrote:
djozz wrote:
First experiments show that the throw/diameter is similar to a common reflector or aspheric lens flashlight, which is pretty good I think.

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.
pilotdog68
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I do like the beam profile form a recoil, just the thermal issues have kept me away from trying to make one.

My Favorite Modded Lights: X6R, S8 , X2R , M6, SP03

Major Projects:  Illuminated Tailcap, TripleDown/TripleStack Driver

EasyB
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pilotdog68 wrote:
djozz wrote:
First experiments show that the throw/diameter is similar to a common reflector or aspheric lens flashlight, which is pretty good I think.
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?

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.

The Miller
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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)
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emarkd
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djozz wrote:
Perhaps that is one one the reasons why there are no recoil flashlights on the market?

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.

djozz
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emarkd wrote:
djozz wrote:
Perhaps that is one one the reasons why there are no recoil flashlights on the market?

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).
Chicken Drumstick
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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.

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Have this one: http://s.aliexpress.com/qMFbuqEb
(from AliExpress Android)

Jerommel
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djozz wrote:
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.

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

Looking for:

5” parabolic reflector (for recoil light)

djozz
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The Miller wrote:
Have this one: http://s.aliexpress.com/qMFbuqEb
(from AliExpress Android)

That one has an even smaller reflector (pure waste of head size!) than the original UF-007 !
fonfan
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Copper LED support must be like Mersedes label star.

WANTED Zebralights. My flashlights

Jerommel
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The Miller wrote:
Have this one: http://s.aliexpress.com/qMFbuqEb
(from AliExpress Android)

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.

Looking for:

5” parabolic reflector (for recoil light)

Jerommel
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pilotdog68 wrote:
I do like the beam profile form a recoil, just the thermal issues have kept me away from trying to make one.

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.

Looking for:

5” parabolic reflector (for recoil light)

ImA4Wheelr
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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.

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EasyB
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To collect close to 100% of the light the parabolic mirror should have its focus point near the height of the rim. Mirrors used in telescopes have their focus point much farther away, which is necessary to make a good image. In that case only a small amount of light would be collected.

Jerommel
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djozz wrote:
pilotdog68 wrote:
djozz wrote:
First experiments show that the throw/diameter is similar to a common reflector or aspheric lens flashlight, which is pretty good I think.

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?
I think it’s because you can’t use normal MCPCBs and you have the + and – leads that have to be long (and thus not too thin).
For a flashlight spill is a good thing usually, or zoomable, not a fixed pin spot.
There seem to be no decent affordable parabolic reflectors out there either, so it’s all unusual parts you need for a recoil.

None the less, modern small footprint high intensity LEDs are ideal for a recoil set up, as they’re hardly in the way of the reflected light (unlike the old XR-E models), plus LED’s radiate their light in the suited direction for a recoil.

Looking for:

5” parabolic reflector (for recoil light)

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Dumb question, doesn’t the “ boom” get in the way of the light?

Jerommel
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EasyB wrote:
To collect close to 100% of the light the parabolic mirror should have its focus point near the height of the rim. Mirrors used in telescopes have their focus point much farther away, which is necessary to make a good image. In that case only a small amount of light would be collected.

In the first drawing i limited the diameter of the mirror to where it was 45°, for a full 180° reflection.
That’s how i found the focal point.
In the new drawing i just used the same, but limited it to about 145° by cutting off some of the rim of the reflector.
So the focalpoint is more or less accurate in the new drawing too.
But, the drawing is for reference only, because i didn’t know how to draw a perfect parabole.
I tried, but it’s apparently almost spherical (concave)…

Looking for:

5” parabolic reflector (for recoil light)

Jerommel
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Beachlogger wrote:
Dumb question, doesn’t the “ boom” get in the way of the light?

Yes it does, but it’s only a thin fin.
I will calculate how many % it would block when it’s 2mm wide.
Probably less than 2%.

Looking for:

5” parabolic reflector (for recoil light)

greenlight
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The reason for making or buying a recoil style light like this is for the Beam shape in particular. Yeah, it’s not the perfect setup, but the beam is so cute! I have the 007 and I would want to try one that was smaller and not as bright.

.

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Been considering doing this for quite a while, I've always wanted a long range spotlight like those HID throwers.

The only issue is that the LED surface area is much larger than what a short arc would be, and far less lumens too.

That leads to a large spread and less intense beam, unless you use a really large reflector.

 

If I do this I will be watercooling the LED, because the distance of the copper "arm" is too long to provide good cooling for a high power LED running at 12 amps or more.

There are some good reflectors from edmund options for $50-100 that are 12-24" diameter and have a short focal length. Problem is that edmund optics import costs are extremely high.

I've ordered a lens from them before and it the COD was more expensive than the lens itself. Can't imagine what it would be like for a 12" or 24" huge box....

http://www.edmundoptics.com/optics/optical-mirrors/focusing-concave-mirrors/large-parabolic-reflectors/1364/

 

Another option is this guy that makes acrylic parabolic mirrors for sun collection, not sure how accurate the parabola is but the 24" and 37" deep parabolics seem pretty good quality, and shipping within the US is cheap.

http://greenpowerscience.com/SHOPARABLOICHOME.html

 

The larger the diameter, the tighter the beam will be. This is really important if you plan to use a large LED like XHP70, SST90, SBT140, or something like that which has lots of lumens.

I'm not sure how large you're planning to make yours, based on the image I would guess 6-12". I am interested if anyone can find a good cheap parabolic reflector below 12" with an accurate parabola.

Remember that the smaller the mirror is, the more accurate the parabola needs to be, and the smaller the LED die needs to be. XP-L HI or dedomed XP-G3 would be optimal IMO.

Best surface brightness (lumens/mm^2) I have found so far.

Hey, how are you? :)

Jerommel
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My idea entails an XP-L HI or an XP-G2 or 3(dedomed) or maybe even a hard driven XP-E2?
I was thinking about 4 to 5 inch diameter reflector.
Finding good ones that are deep enough to take 145° of light is indeed the problem…
…that is, when you’re on a tight budget…
For this to get built by the hundreds i think they would have to be custom made in China to make it affordable.
I fear this is where this idea will cease..
I’m hoping for someone here with the right connections with Chinese manufacturers.

Looking for:

5” parabolic reflector (for recoil light)

Enderman
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Jerommel wrote:
My idea entails an XP-L HI or an XP-G2 or 3(dedomed) or maybe even a hard driven XP-E2? I was thinking about 4 to 5 inch diameter reflector. Finding good ones that are deep enough to take 145° of light is indeed the problem... ...that is, when you're on a tight budget... For this to get built by the hundreds i think they would have to be custom made in China to make it affordable. I fear this is where this idea will cease.. I'm hoping for someone here with the right connections with Chinese manufacturers.
 

I think a cheap and good reflector from china will be very hard to find...

The smaller you go, the more accurate it needs to be if you want a good beam.

I highly suggest you install optical ray tracer to test that the reflector properly focuses light, since usually the only information given is the depth and diameter of the reflector. http://arachnoid.com/OpticalRayTracer/

Also, a big problem with getting stuff from china is that even though it is low price they usually have a minimum order quantity and you can't get something unless you buy a set of 50 or whatever.

But search around, test the mirrors with the ray tracer and see if you can find a decent one at a good price.

 

You need to find something like this, but cheaper: http://www.edmundoptics.com/optics/optical-mirrors/focusing-concave-mirrors/precision-parabolic-reflectors/3096/

$300 for a 4" mirror is way too expensive even for me...

Hey, how are you? :)

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Might I suggest having a play at this site Grad

http://www.intmath.com/plane-analytic-geometry/parabola-interactive.php

For cooling how about miniature heat-pipes, think of an upside down Mercedes symbol, you could use three or four in line for one support and use two of these for the top two supports, with the third (bottom) support just being 1mm flat copper.

Just throwing it to see if it sticks Wink

Cheers David

Edit, forget the three or four miniature pipes (expensive) however they do 2.5mmx8mm for laptops fairly cheap.

Nothing to see here folks, move along...

 

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Even if you guys could find a suitable host and reflector, won’t the placement of the led with big limitations on heat transfer limit the Amps the led will be able to endure?
And thus limit the beam intensity – throw of the light?

If a light like this can use 100% instead of roughly 75% ot the light for the spot, but the led can be driven at 75% of maximum, where’s the benefit? (other then beam characteristics).

The heat transfer will indeed be the big limiting factor, so just one arm would probably not suffice. Maybe the “Mercedes” star design would be best?

Interesting idea, bu waiting to see whether it can be turned into a practical design.

Grtz
Nico

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