Fanned SST90 focusable handheld searchlight

My first mod/selfbuild, inspired on the Mitralux 131 searchlight.

I measured it at 88.000cd, but Nimh batteries are not full, so expect it to apporach 100.000cd.

SST 90
DIW-Driver 9 Amps
2x4AA Nimh Eneloops
5v fan
75mm Edmund Optics aspheric
1 mode - full on

The housing is a zoomlens that I sacrified, giving travel of 40mm to the lens. It goes from (led far from lens) halo/ring - to spot - to sharp die - to flood (led close to lens ).

As the Led is deep inside the housing, I connected the copper heatsink to finned heatpipes, ventilated by the fan in the battery compartment.
This works well, not cooled superb, but after 6 mins running, the light output drops no more.










The gain compared to more conventional designs is that is is focusable and steady output without thermal sag.

This isn't home-made section is it .... :duh2:
But I did machine:

That is just too cool. Talk about a tactical flashlight. Beamshots please.

I'd be scared as hell if you pointed this at me!

How far does it shoot? :naughty:

No seriously, this looks insane, just the way I like!

Hi Walterk

Interesting that we're working on similar concepts on the opposite sides of the world - Searchlight Spot to Floodlight using SST-90 cooled by Heatpipe. I'm also using a rectangular metal box instead of the traditional torch shape.

I'm using LiIon batteries instead of NiCd.

Because I want to have a wide range of beams types and light sizes, I'm taking a modular approach using PVC plumbing fittings to house the optics - up to 140mm dia 500mm focal length lens !

I'm working frantically to get it ready for Search Exercise we have on this weekend with the Police, so I won't be posting any photos till next week.

I've also found that putting a 50mm Aspheric lens close to the LED really helps with the output Lumens when using long focal-length lenses.

+1 on the beamshot.

Really cool.

You probably started alot of peole thinking. Good job.

Wow! That cooling is fantastic. :twothumbs

We've been talking about fan cooling in another thread in this section but you've actually built it! Read the first paragraph of what I posted earlier today here - you will get a laugh:

https://www.candlepowerforums.com/posts/3557259&postcount=7

I had to go back and look at the time stamps - 5 minutes before you posted.

Absolutely terrific work on that light.

Very nice !

How warm is the air coming out of the battery box?

Consider relocating the batters to under the "muzzle" to eliminate their heat and get the heat sink to open air.

Maybe add a small peliter for fun since you have so much room for batteries

wow! +1 on the cool factor

Walterk said:

. . . The housing is a zoomlens that I sacrified, giving travel of 40mm to the lens. . . .

Click to expand...

You had me wondering !!!! I was sure you wouldn't consider using photo lens.

Photo lenses produce great quality, but they do this by sacrificing quantity (of light).

Many aspherics used by CPFers are better than F0.7 - if you can buy an F1.0 camera lens, it will cost about a $1000 !

Most affordable photo lenses are at least F2.8 - but only transmit one-sixteenth of the light of an F0.7 lens.

Actually at first I wanted to use the photolens, I wanted to put a HID behind it. That was my first thread at this forum. After some reading at CPF I learned better ways.

The temperature of the air is (by estimate) 10-15 degrees warmer then the outside air. You feel it is warmed up, less cold, but it's not hot at all.

Beamshots will follow, within a month or so.

Wow, fantastic!, you just need to add an aiming laser, so you can aim it before you set stuff on fire

With your heat problem solved, would you consider something like an external battery pack to be a solution for more capacity? It'd be neat to see.

WOW, talk about a light cannon!

Walterk said:

My first mod/selfbuild, inspired on the Mitralux 131 searchlight.

I measured it at 88.000cd, but Nimh batteries are not full, so expect it to apporach 100.000cd.

SST 90
DIW-Driver 9 Amps
2x4AA Nimh Eneloops
5v fan
75mm Thorlabs aspheric
1 mode - full on

The housing is a zoomlens that I sacrified, giving travel of 40mm to the lens. It goes from (led far from lens) halo/ring - to spot - to sharp die - to flood (led close to lens ).

As the Led is deep inside the housing, I connected the copper heatsink to finned heatpipes, ventilated by the fan in the battery compartment.
This works well, not cooled superb, but after 6 mins running, the light output drops no more.

Click to expand...

You mention you used the thor labs 75mm and you got it focus with sharp die. I have this lens and it doesn't focus well for me and gives lots of spill. Did you use a second lens to collimate or something? Really cool design btw :thumbsup:

I have:
75mm DealExtreme (best value for money, better then Thorlabs for our use )
75mm Edmunds (love it, for my next project )
75mm Thorlabs (bad, but good enough for this toy)

So I agree the Thorlabs doesnt perform well. But I had it spare so I found a reasonable purpose for it.

Some links on my search for good lenses:
75mm aspheric lens source, post 24 for DX lens beamshots
Another aspheric lens question, for some comparison I did.
The best way to test is to do an actual test with the led you want to use.
Formula for calculating throw using aspheric lens, about using pre-collimator or not

Very cool!
You may need a Pachmayr recoil pad on it!

Illustrious,...! WTHeck...

Some beamshots: sloppy camera, but capturing the beamshape.
Parkinglot with trees at 50 meters.
I think the Halo is typical side-effect of using this to-short-focallength-lens...?



http://www.modelbouwforum.nl/forums/members/walterk-albums-algemeen-picture47405-shots.jpg

Insane! :thumbsup:

That is WICKED awesome......:duh2:

gt40 said:

You mention you used the thor labs 75mm and you got it focus with sharp die. I have this lens and it doesn't focus well for me and gives lots of spill. Did you use a second lens to collimate or something? Really cool design btw :thumbsup:

Click to expand...

Sorry to hear GT.
This unit has a Edmund Optics lens inside.
(I corrected the text, as I earlier stated it to be a Thorlabs.)
The Thorlabs I have works well, maybe there is some variation.

The Edmunds has a hot spot in the center, and the other part of the beam is less intense. Th projected die is sharp, but with loads of coloured rings. (Tested with XRE-R2)

The Thorlabs focusses less sharp, but the lux-reading is about the double, and overfocussed the light within the beam is nice even spread out. (Tested with XRE-R2)