Well, I have a 1/2” thick FR plate in G10, a lens, a tube and some Kydex. Also have a laser module and a bunch of batteries and some various bits and piece of aluminum and copper. One of these days the creative urge will overpower me and I’ll get to work on this project. (read, I’ll get bored and attack it for lack of anything else to do) I might need a piece of aluminum plate, and will certainly need some lighted rocker switches and toggle switches. Military paint is semi-procured, still need to confirm that. I do have a driver now that should do the trick, although it’s not on the line I was first thinking. The original plan was for a primary driver and 2 slave boards for a 3 stage boost set up, still have to figure out how I’m going to go about this part.
Still trying to decide as to whether or not I should use a secondary focusing optic and my primary advisor is AWOL. Without that input I’m not sure what parameters to look for in the secondary lens. I want maximum throw and am fairly sure a 2 lens set up will sacrifice throw in favor of a hot spot with virtually no spill. So there are things that need sorting out before I dive in.
No Titanium will be sacrificed in the making of this light.
That’s the really cool thing Scott! It’s virtually weightless!
I was in communication with a forum member that has a very deep grasp on aspherics and double aspherics when I set out on this journey. This member has gone incognito for quite a while now, so some of the information I was counting on him to supply is missing from my equation. I will eventually proceed, who knows where it’ll end up.
Thanks EasyB, this all started when a friend saw a deal on ebay and shared a link… apparently a large company had ordered quite a few 200mm condenser lenses turned down to 7”, then didn’t use quite all of em. I got this $150 lens for $30. It’s got a 16” back focus so part of what I was counting on was help determining what lens to use in front of an emitter to focus the light into this big condenser. I have formally not been very fond of aspheric lights, so this is way outside my ball park.
Loosely holding the big 7” lens out front of a de-domed XP-G2 it does indeed make a super small hot spot, so it should have some seriously monster throw, maybe even exceeding 1Mcd, possibly, done right, even exceeding 2Mcd! How cool would it be to dial in a 2 mile thrower? That’s what got me started here.
I’ve purchased an 8” tube, 4’ long, I’ve got some aluminum stock I can make a base holder for the emitter and driver and I have some material I can probably fashion into a carrier plate for the big optic, pretty sure I even have it figured out how to affix it. This is a combination of a 1/2” thick plate of FR plate and 1/8” Kydex. So I’ll still need the back side 8” plate, threaded for focus ability, and probably a threaded on mount for the secondary lens. Which lens, that’s my problem. I look at the Edmunds catalog and there seems to be quite a few things that could possibly work, figuring I’ve got it narrowed down to one I’d like to try, but don’t want to start dropping $35 on lenses that aren’t quite right for the job at hand, if that makes any sense.
I’ve even got a second aspheric that goes in the Jax Z1 aspheric, not sure if that one might work just as well, longer back focus probably than is desirable as I’m thinking this secondary should be practically right on top of the emitter.
I know enough to know there’s trade-offs. I can gain lumens by using the double glass, but the overall throw is better with the single primary. So it’s going to come to a point that I’m going to have to build it as a single with concession applied towards an additional lens, see how it goes.
For a little perspective… I have an SBT-70 in my Jax Z1, if I focus it on the wall across my room the hot spot is about 9-10” in diameter. If I remove the aspheric and focus it through this condenser lens, the hot spot is about 3/8” in diameter and looks like it’s going to start a fire! And that’s from the big SBT-70!
That looks like a high quality lens. Here are my thoughts and suggestions. I actually think the Z1 lens might work well as a precollimator lens. For high light collection efficiency you want to maximize the lens diameter to focal length ratio, but it’s hard to get this ratio much larger than 1 and still have good lens quality (from what I’ve seen). I think the Z1 lens has a ratio probably around 1 and I’ve heard it is good quality.
Here is how I would choose the location for the precollimator lens. Rig up the large lens so that it is in place, 16” from the LED. Then hold the Z1 lens and start very close to the LED. As you move the Z1 lens farther away from the LED, you should see the cone of light coming from the Z1 lens start to narrow. Keep moving it away until the light cone narrows so that it’s overfilling the 7” lens by 1 to 3”. Around this configuration is where you are going to maximize the light collection efficiency. This should approximately double the beam area and hopefully not drop the lux by more than 10%. Fine tune the 7” lens position to get focus because adding the Z1 lens will change this distance slightly.
That’s about what I was thinking but was worried about the Z1 lens having that 2.75-3” back focus. It’s pretty far. I build a precollimator set up for the Z1 and while it did improve lumens at zoom it also made a larger hot spot by a good margin. (the secondary was pretty cheap)
I just simulated that by leaving the aspheric on the Z1 and focusing it through the condenser lens. This virtually eliminated all spill but kept the hot spot the same diamter. So I will gain overall output lumens by utilizing the Z1 secondary lens, gain throw by keeping only one lens.
The motivation for using a precollimator lens is to increase beam lumens while keeping the beam intensity the same. The extra lumens manifest themselves as a larger hotspot.
Dale, have you tried a zoom position between spot and flood? I was thinking, if your big lens has a focal distance of 16”, then maybe set the Z1 to a zoom setting that just covers the back of the big lens at about that distance. From there, move the ‘zoom’ position of one/both lenses just enough to get a good focus while also trying to keep the back of the big lens completely lit.
I don’t know if this is anything like plausible, just popped in my head.
Trying something. Just bought a broken camera lens off ebay for parts. I’ll disassemble it and try to make use of some of the 21 optics inside. It’ll be fun taking it completely apart at the very least, I’ve used this particular lens before and had one during two different periods so I’m pretty familiar with it. There’s an aspheric inside as well as multiple condenser type combination optics. We’ll see next week if any of it will be useful to this project or not.
