New Aspheric thrower build

Hey all!

Just sharing the results of my most recent aspheric thrower build here...

I had some of the parts I needed laying around and had wanted to do this project for a while so I ordered the rest of what I needed and put it all together. Overall, I’m very pleased with the results!

First, a bit about the host! For this build, I selected the Ultrafire WF-501a host from Manafont for two reasons. First, it was cheap. Second, it would take CR123a cells, which I have an abundance of, but no light to use them in. This particular host is the 1x CR123a-sized version of the revered/reviled WF-501b host.

This host is of rather cheap construction: Machining marks are prominently visible, it has a cheap tailcap boot, and the thin/glossy anodizing/paint(?) that is not used on my higher-quality lights. Cosmetics aside though, it’s well suited for this project.

I had an additional XR-E R2 drop-in from the DD $5 deal, which I decided to re-allocate for this light. I removed the factory driver from the DD drop-in and replaced it with sku.25505 from DX. This driver used with a single Trustfire Flame 16340 cell results in a tailcap current reading of ~1.7A, somewhat overdriven, but not excessively so. I set the DD OP reflector aside (spare parts!) and replaced it with a SMO reflector painted flat black, to eliminate the ugly ringiness that would have otherwise been present in the beam.

For the optic, I used my older 28mm aspheric optic from DX, not linked to here since reviews indicate that the newer versions of this optic are very poor quality. The short-range beamshot here shows that this optic results in a square (but not perfectly focused) beam.

I have attempted to focus this better, but have been unable to improve these results. For normal outdoor use though, this beam is sufficiently focused to make this tiny and pocketable light out-throw my Trustfire TR-1200 with 5x XR-E Q5 emitters. Light measurements taken (using my cheap and universally considered untrustworthy DX lightmeter)@ 20’ and recalculated to the standard 1 meter value indicate a spot intensity of 26,300 lux. My normal outdoor nighttime target, a barn that is a known 700’ from my house can be brightly illuminated using this lamp. Overall, I am very impressed. I have shown this light to several of my friends and they are also shocked at the range such a small light can have.

nice project - I need to do a little fixed thrower like this - don't have any 123 batteries though lol

fyi, i received a DX 28mm aspheric (about) 2 weeks ago and it projects and image of the emitter about like what you pictured...slightly unfocused. The problem is, you also get 3 or 4 dimmer images of the emitter scattered about and overlapping it

and have been reading that the new ones are no good. anybody know where to get some good ones?

Nice work! Keltex79 is there a problem with your lens (as others have had lately) or is it just not quite at the proper focal point?
If you take the lens before it is mounted and move it back and forth in front of a bare emitter does it focus properly?
When the focal length isn’t perfect for the host and when the host is a P60 type host then it’s hard to do any fine adjustments since the depth of the reflector (being used as a spacer) is fixed.
If you are over focused you could grind of a bit off of the front of the reflector. If you are under focused there’s not much you can do unless you make your own spacer.
With lights that use screw-in pills you don’t need the reflector and can generally unscrew the head a bit to fine tune the focus.

The lens has a bit of a swirl in it so I'm not expecting it to be perfect. I found that removing the aluminum lens retaining ring and installing it backwards moves the drop-in back a bit which helped achieve the correct focal length. I had an o-ring installed between the reflector and the lens, but that wasn't quite enough width to put it in focus. I may play with trying to focus it better in the future, but overall, I'm happy enough with the way it is now.

I agree. It looks nice. I’m not too bothered by an exact focus either.
Sometimes I defocus them even more for a larger and rounder hot spot as long as it still throws as far as I need it to throw.

dx/kd/lightake aspheric lenses quality sux lately. My hit rate has been about 1in4 good regardless of size. Not only is there swirl but micro bubbles which result in multi images and poor light transmission. We need better quality lenses.

definitely agree on that. I think the demand is growing so maybe we'll see some new offerings.

the best chance might be to give DX feedback. maybe they'll get the manufacturer to step it up a notch, or 10.

I have a DX lens in a 501b (r2 emitter) and an Ahorton lens in a second 501b. I compared the two and the DX lens projects multiple blurry images while the Ahorton lens shows a very clear emitter image. However, the Ahorton required trimming about 1/2 inch off of the reflector to get it to focus (the Ahorton is a much thicker lens). The DX lens did not require any modifications. Now the internals dont fit very well (with the Ahorton) and the light rattles. I have not come up with a fix for this yet.

Nice build keltex.

I found this seller on ebay that seems to have same type of lens but I have no idea on the quality
http://www.ebay.com/itm/5pcs-High-Power-LED-28mm-convex-lens-optical-glass-/170615864246

That's funny I built the exact same light 501A, Q5, 1.75 amp with an old the DX lens a couple weeks ago. I used a leftover emitter from a MCU-C88 and a leftover driver from an A30B so it's direct drive and it pulls exactly 1.75 amps. Very cool little light and very strange coincidence. I actually built mine to mount on a rifle so I will be adding a rat tail switch when I get done playing with it.

Great build! Just gotta find these lenses.
Anyone tried the one from FastTech yet?

http://www.fasttech.com/product/1404701-28mm-5-90-degrees-plano-convex-lens

i got 10 of these lenses and i’m about to send it back… it’s not the same as pics,
it’s cheap plastic not glass as advertised and the beam are horrible

The 100mm one was featured in the DST aspheric (done by IAM4Wheelr, I believe) and I believe it was ID’d as glass.

I have a 23mm version that is clear and a good replacement in an SK98 - FT insists it is glass but I’m not as certain (from memory it is only slightly heavier than the oem plastic lens).