No, it's a precisely ground glass mirror (spherical) that is then coated with a dichroic coating. This type of coating allows for a very high reflectivity. To get similar performance for less money you can use a precise aluminium reflector that is then coated with an aluminium coating. This will get you around 90% reflectivity, close enough. The Wavien collar is slightly better, but with much higher production cost.
If you want the pre-collimator to be very effective it needs to be right above the LED so that it can collect all of the emitted light.
The_Driver, I understand what you are saying but if they are not available what else do you do? Myself I improvise and it is a hobby. The lights I build are to see if I can do it and to amuse myself, most of them I have no use for. But I do have an aim and that is to scale some small lights up as big as I can, not to break records or for any commerical purpose just for fun.
My Old Lumens comp light it is a prototype that I wanted to build I just didnt know how or if the idea I had would actually work. I have 4 BLF GT reflectors and 4 SBT-90.2 for a quad Im not sure about cutting the reflectors so I will build a few smaller ones first.
The information on the precollimator lens thanks it was very helpful. You are right about the spherical lens.
I found this actuator housing in the bin and I think I can make something cool out of it.
The 150mm lens is slowly getting a light engine this will have a K75 driver, SBT-90.2 and a marinebeam rlt collar. Lens is 150mm diameter and has a 177mm back focal length.
The battery tubes will go here but the back plate wont fitt in my lathe. Havent thought of a way to do it yet
I have access to a big lathes at work but because it isnt my trade I cant just use them the tradespeople will freak out. I think the backplate will have to be changed or redone anyway. I could cut the battery tube mount off, cut the threads and then bolt that to the new plate. That is the way im thinking as weight doesnt really matter it is heavy anyway.
This is a copper piston for the led to sit on. the lights heatsink will be bored out for the piston, seals in either end of the barrel will contain the thermal compound and the piston will be driven by a leadscrew.
I have a week off so I will be self isolating and enforcing the get lost rule so I should get a bit done.
It is funny that recoil looks like garbage but will trow further than anything else I have w30 k75 gt. I made it like that because I damaged the reflector. But I cant stop there so I ordered the 24inch version from edmundsoptic. I also got rorted on ebay with an 8inch francis reflector. I think enderman posted the link on ebay to a glass mirror. So I had to have an 11inch with 6inch FL. The other day on ebay I randomly searched parabolic mirror and what do you know there is a 1940 era 36inch glass search light mirror 4hours drive from me. Made an offer got a bargain and I pick that up on tuesday.
Beamshot of 11inch glass mirror sbt-90.2 @12amp! w30 is on the right
Wow !! grin
I think you have taken the King of Big Lights title
Have you considered cooling the led in your 11inch glass mirror sbt-90.2 @12amp ?
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” Enderman ” cooled his like the pics below.
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Could you please draw us a sketch on paper and I will transfer it to CAD and verify it thru a PM with you and then you can post it here for clarity reasons. I’m having a hard time putting your description together in my head. THANKS
. And one more thing Please, Where are you buying your lenses ??
BTW … GREAT BUILDS !!!
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I have read Endermans thread, more than likely it will have the same driver. Water cooling, it is the easiest way to get the heat out. I am waiting for a borosilicate 3d printer base that will be used for the lens. I can then finish the front of the light.
There is still a lot of work to do.
I will do a sketch for you in a day for 2 when I get a bit more done. Haha I have to get it out of my head and into metal first.
Forgot to add I have purchased lens from lot of different places aliexpress has some good one but you have sift through. I have one of these
Edmunds optic is where I got the 150mm daimeter FL 200mm and 150mm Fl 300mm
I have a 200mm diameter FL 400mm on order, this is where the secondary comes in. A second lens will be able to shorten the focal length to a more reasonable length. Although the projected image will be bigger no matter what I think you gain overall. edmundoptics
I have got a lot of different smaller lenses. From ebay, aliexpress, fastech, kaidomain
Im not sure what you mean concave convex lens? I have not had any success with them. The ones that project the best are plano convex. Double convex doesnt give as good a beam.
Thedriver mentions spherical lens very close to the LED I have some on order because a bit of research sayes that he is right. So then I will then build a 3 element projector light and see how it goes.
I am talking about plano convex lens. At diameters larger than 100mm, the selection of aspheric plano convex lens is difficult to find. In addition, the price is also higher for large aspheric plano convex lens.
Spherical plano convex lens have more selections, are cheaper and can be produced with very high precision.
I personally never tested spherical plano convex lens before, so I am asking for how you feel using them.
Thank you for sharing experience with bicovex lens. I thought they would perform about the same.
CNCman, Here is a basic drawing of how the focus will work I done have the motors yet so not sure how they will mounted. There also needs to be a way for air to escape from between the seals. Im not even sure this will work yet.
What does the gear drive to the heatsink provide—is it for a water pump?
It will work for awhile, the airgap will reduce the cooling ability of the copper piston. It needs to contact and touch the heatsink for better performance, air is a poor thermal path.
likevvii,
The edmunds optics PCX lenses are formed from a radius. A line drawn from one point on the circumference of a circle to another is a chord. so if you then think of that circle as a sphere and cut the sphere through that line you get the PCX lens. Im not sure what the geometric term for this is. To me the plano spherical lens has a focal length close to the diameter and is a bigger portion of the sphere. So i am not really sure what the difference is. an aspheric lens is 2 lens in one lens so now I am not even sure why a zoomie is even called aspheric. Because mine are definitely not aspheric lenses.
I wondered why the w30 has a plastic double convex lens. So I got a bit of actuator housing and an old fitting and made a lens carrier for a 127mm DCX from a desktop magnifying glass. The results are not very impressive however put the light engine behind a 2 element PCX lens and the results are impressive. The focal length is also shorter with the w30 light engine that is because between the 90° mirror and the phosphor crystal there is a small lens less than 10mm diameter and less than 5mm off the phosphor. Now this lens puzzles me to me it looks like a PCX. But because of what Thedriver posted I dont think it is. So the lenses I have on order should give me the answer. So back to the DCX does this make the w30 a 2 element lens? I would say yes so that then makes the DCX lens an objective lens or primary, this makes the other lens a secondary. Which collects light and directs it toward the primary.
This is my opinion and if someone doesnt agree Im all ears as to why. The shorter the focal length of a lens the thicker it has to be the thicker the lens the bigger the loses and more distortion of the image. Therefore a longer focal length lens is thinner, the thinner it is the less the loses are. So a multiple element lens collimates the beam in steps. by using multiple lens the overall focal length can be shortened. this also distorts the led image less and the primary lens is the lens that gives you the throw and is the most important one to completely light up. So the secondary lens sets the light up for the primary to throw it down the paddock.
Big lens are expensive and heavy but the result is well worth it. I pondered and dreamed about them for a long until one day a few beers made me brave and I thought do yeah why not. I will only regret it untils next weeks pay, ever since I look back and think which one was it that trowed me of that cliff.
The motor will drive the piston up and down to zoom. The light in and out. the gap will be small and filled with thermal compound. There is a lot of thermal mass in the piston, it weighs more than the K75 Light. It also has a large surface area and that is what I hope will make up for the poor heat transfer. There is a huge amount of aluminium and copper to heat up.
but the result is well worth it. I pondered and dreamed about them for a long until one day a few beers made me brave and I thought do yeah why not. I will only regret it untils next weeks pay, ever since I look back and think which one was it that trowed me of that cliff. 
Will be watching 