Howdy, Ghost!
I’d like to help.
You picked my favorite 18650 toy torch!
Modding is a blast! You are among friends on this forum, so stick around?
Meanwhile, a few suggestions to get you started:
First, the torch you bought is in a class, called “P60”, which all take the same “drop-in” (the reflector, light source (LED or incandescent), circuitry to connect it, and metal to hold it all together while you “drop” it “in” your torch). All the parts have specific names, using which will make this conversation much more smooth. You can find out a little about the “P60 Host” here: P60 - Flashlight Wiki
Moving on…
You’ll need tools. Staying on topic here, the first best tool I can suggest (since you’re already a DX customer) is this:
Digital 150mm Caliper - Free Shipping - DealExtreme
Here’s why I suggested that first: The lens you bought is AKA “aspheric”. It’s purpose is to “collimate” or focus the light OTF (“Out The Front”) into a tighter beam for more “Throw” (useful illumination at a distance). They make these by the boatload, all shapes and sizes. Notice yours… It’s listed as “28mm” in Outside Diameter (“OD”). Did you check the P60 Wiki (and the DIY link if you’re courageous)? The glass lens, which the aspheric will replace, is only 26.5mm on the P60!
Bottom line, you are about to become very skilled at grinding glass! You can tell me how that works out, because I’m allergic to broken glass… :zipper_mouth_face: All I know is, you’ll need a powered grit-mover (belt sander, grinder, etc.), something sticky to hold the lens, and lots of clear cool water or other coolant.
Given your current situation, your solution is to grind the excess OD away, until you get to the ~26.5mm OD which will fit. As you can see, you may have to re-do the “lip” around the edge. Not the best answer, but I think you can see why.
Your only other hope is to either build a new head for your 501B (not as ludicrous as it sounds, in this company); or to find another light with a 28mm lens for your aspheric. There is no “right answer”, but you could count this as “tuition” and just go find a 26.5mm aspheric (DX is OOS, but they’re easy to find).
Other than that, everything else you could possibly want to know about “P60 Hosts” is here on this Forum, in massive loads and wide distribution.
Best of all, you’ve found the Best Forum On The Internet for this sort of thing!
I feel awfully cheeky (as another FNG) to say “WELCOME”; but you ARE, as you’ll see, and I sincerely appreciate you giving me this opportunity to be of some Service here!
Dim
(edit: Sorry I forgot, the name of the tool for unscrewing the locking ring is called “Needle-nose Pliers”. You may have to grind the tips some… I use medical tools called “Hemostats”, but they can be hard to find.)