grins projector, recoil and test light builds

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grin
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There are a few ideas I have for some cool beam shots. The cliffs I posted photos previously being one idea.

grin
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I have had more than a few goes at trying to get I think it is a lantern style of light right. Anyway this is the latest attempt.


The lens and reflector somehow got more than usual.












LED is a cree cmt-1945 5000k, driver is a taskled HBflex, it doesnt have a battery yet but is setup for external power from an 18v makita battery. the back/battery pack and base are still to be designed and built.

MRsDNF
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Your work is pure pawn grin. Beer

 

djozz quotes, "it came with chinese lettering that is chinese to me".

                      "My man mousehole needs one too"

old4570 said "I'm not an expert , so don't suffer from any such technical restrictions".

Old-Lumens. Highly admired and cherished member of Budget Light Forum. 11.5.2011 - 20.12.16. RIP.

 

kennybobby
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i like how you tapered the body section with the heat sink fins, that adds some style points to the looks.

Plus all the large diameter inside fine threads that you’ve been able to cut.

cheers to ya.

[edit]

Now i used to think that i was cool,
drivin' around on fossil fuel,
until i saw what i was doin',
was drivin' down the road to ruin. --JT

grin
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Big Smile Beer
Enderman
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Nice build… now that’s a big boy flashlight hahaha

A while ago I actually purchased one of these
https://www.amazon.ca/SMALLRIG-Handle-1447-Rubber-Black/dp/B00MP2YEMG/re...
And a 25mm led ring push button switch fits perfectly in the handle, since you can easily remove the black end cap

Makes a really nice and comfortable handle Smile

grin
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I have some similar to those handles although you cant get a switch them. Contacts in the handle base like a camera flash would be good so the handle could be removed easily. Then remote switch magnetic base so I can put it on the roof of my car for out bush. Big Smile
Does anyone recognise what the front is from?

MRsDNF
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kennybobby wrote:
“pure pawn” is that an Australian expression? not sure what it means over here

I was using alternate spelling so not to attract the ire of sb.

 

djozz quotes, "it came with chinese lettering that is chinese to me".

                      "My man mousehole needs one too"

old4570 said "I'm not an expert , so don't suffer from any such technical restrictions".

Old-Lumens. Highly admired and cherished member of Budget Light Forum. 11.5.2011 - 20.12.16. RIP.

 

raccoon city
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MRsDNF wrote:
kennybobby wrote:

"pure pawn" is that an Australian expression? not sure what it means over here

I was using alternate spelling so not to attract the ire of sb.

Ah, yes, sb doesn't like the word for "adult entertainment" on BLF because this site might be classified as an "adult website."

 
The_Driver
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grin wrote:
Haha i would like t9 see it from a plane. with your calculator it comes out at 119Mcd. Here is a video taken that night by another forum member.

 

Very cool! cool

I'm wondering though how you got such a high lux number with the calculator.

A 900mm reflector has a surface area of around 636,173mmminus the dead part in the middle where the LED heatsink is. You need to multiply this with the reflection losses.  Since you are using a very old reflector I would go with 70% here. After this you just need to multiply this with the luminance of the LED.

 

COB LEDs have a rather low luminance. Your COB, the Cree CMT2890, has an LES of 22mm (diameter of light emitting surface). This allows for a rough calculation of the luminance by dividing the lumens by the surface_area x pi. At 15,000 lumens your LED should have an average luminance of around 12.6cd/mm(COB LEDs have many small dies with dead areas in between them so the real area is smaller and the actual luminance a bit higher). Multiplied with the area of the reflector I got around 8 Million Candela. This shows that you are leaving quite a bit of performance on the table. A Luminus SBT90.2 should easily reach 200cd/mm2 while giving you 1/3 of the lumens. Also, there a much brighter COB LEDs on the market if lumens are more important to you. 

Enderman
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The_Driver wrote:

grin wrote:
Haha i would like t9 see it from a plane. with your calculator it comes out at 119Mcd. Here is a video taken that night by another forum member.

 


Very cool! cool


I’m wondering though how you got such a high lux number with the calculator.


A 900mm reflector has a surface area of around 636,173mmminus the dead part in the middle where the LED heatsink is. You need to multiply this with the reflection losses.  Since you are using a very old reflector I would go with 70% here. After this you just need to multiply this with the luminance of the LED.


 


COB LEDs have a rather low luminance. Your COB, the Cree CMT2890 has an LES of 22mm (diameter of light emitting surface). This allows for a rough calculation of the luminance by dividing the lumens by the surface_area x pi. At 15,000 lumens your LED should have an average luminance of around 12.6cd/mm(COB LEDs have many small dies with dead areas in between them so the real area is smaller and the actual luminance a bit higher). Multiplied with the area of the reflector I got around 8 Million Candela. This shows that you are leaving quite a bit of performance on the table. A Luminus SBT90.2 should easily reach 200cd/mm2 while giving you 1/3 of the lumens. Also, there a much brighter COB LEDs on the market, see here, if lumens are more important to you. 


I would assume he’s using the 200cd/mm2 from the SBT90.2 otherwise it’s not above 100Mcd.
With 200 it does show ~120Mcd but that’s only with a perfect mirror, so you’re right he should be doing like 70-80% reflectivity to get more accurate numbers.
The variable for that is in the “intensity calculations” folder in the calculator Smile
There is also a glass transmission variable which can be set to 1 since he is not using any front glass for the light.
grin
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You are correct I would trust your calculations over mine but when I looked again that number is for the sbt-90. My measurement is usually “it hurts my eyes so it must be bright” and “I pointed it at that house 2km away and they called the police it must throw a fair distance” haha around 3am one morning I lighted up someone sleeping on the job over 2km away.
I am trying different light engines out of curiosity and also to get a feel of what the mirror is capable of. SBT-90.2 is impressive, HID is good fun, CMT puts out a column of light. Looking at original light it was designed to be carried by hand so everything has handles built in, the genset was towed on a truck. By the looks of it the carbon arc assembly sits inside an enclosure inside the drum. Looks like it dropped in and was fastened so it didnt move. In my lights I would like to have it the same but build the cooling system, driver and maybe even a battery into the one module. That way if I was to hire them out depending on the use the light engine can be changed. I want one portable and one mounted on the mini dump truck. How would a plasma cutter or a tig welder go for a light engine? A small bottle of argon would last an hour or 2 to purge the oxygen from the electrodes about the same as carbon rods.
Screen shot from google of the 90cm carbon arc searchlight.

CNCman
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The things you are doing are very impressive and entertaining. I enjoy watching all your projects, of course the big mirror is top of my list. You sparked our interest in those WW2 search lights and the carbon arc movie theater projectors too. The search light mirror could shine 25 miles and the one you have did too. What history you are in possession is very interesting and honorable to give life too again. Beer

lightknot
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Spectacular projects, especially interested in the W30 build(s). Can’t wait to see what you do with a W50!

Carpe Diem

Xandre
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Great projects

Really enjoy and like it Thumbs Up

Regards Xandre

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