Hi guys, I moved on to the next project. I picked up a 2 D 3 watt "trailblazer" flashlight yesterday. It is Maglite size but had a direct drive XR-E emitter and much deeper reflector than the maglite. It was dull and unimpressive at three volts (.67 amps at the tail cap) so I tossed in my single 18650 conversion tube and the light is now my brightest and best thrower (2.1 amps at the tailcap). Thats the good news. The bad news is that beam pattern in noticeably ringie (sp) to the point of distraction. I suspect that a better quality reflector would make a difference in beam quality. The reflector and lens are plastic and 46 mm in diameter. I have searched all the main sites and can't find any light with a reflector of this size. Anyone know when I could find some parts (46 mm glass lens and 46 mm metal reflector) to tart up this light?
Thanks for the catch on the scale for current. I changed it in the post above.
I'm reluctant to try and turn a reflector that large down to size because of the difficulty in holding the work will turning material off. I have done a couple of smaller reflectors but the challenge increases as the cutter moves further away from the centre of the work. If the cutter grabs, it twists the work out of the chuck and the reflector will be ruined. But if I cant find something in the correct size I guess that will be teh only option. Any idea if an eye glasses shop could cut a lens to fit?
Umm... It might just be cheaper to get a 43mm lens and wrap an o-ring around it (assuming your lip across the front is wide enough to more than make up the difference). FlashlightLens.com has UCL lenses in 43mm, which should cost around $8.50 delivered ($6.25 + shipping)
As for the lathe, I've never tried to cut the open end off a hollow piece before. All I ever really dealt with was 1" barstock.
I have no shop skills to speak of :) but I do know that glass is soft. I used a friends bench grinder to reduce the diameter of an aspheric lens. They are thicker and less prone to break while doing this of course but if you have or have access to a bench grinder and can find a lens that is a little larger it's not that hard to grind it to your specifications.
I just attempted to shorten a stock plastic maglite reflector! It did not go well. To much flex and the final product looks awful, plus it ended up way to short when I reduced the diameter to 46. There is a noticeable difference between 52m and 46 mm.
Devman, I didn't get the impression that he was looking for an aspheric lens but rather a flat piece of glass.
That would "tart up" his light though and he wouldn't need a reflector if he wanted to make it an aspheric thrower. I have that aspheric but it's in a light and hard to measure the focal length exactly now but I think it's in the range of 12-15 mm.
Thanks guys for keeping me in mind! Are there any design issues to building an aspheric lens setup? I'm pretty new to this addiction, so knowledge level is pretty thin! Do I have to worry about the distance from the emitter to the lens? bUt you have piqued my interest. I will have to measure the lip that puts pressure on the lens to see what the min dia is that I can still get a seal with.
The best thing to do is to just order a couple of aspheric lens. They are cheap when you can find them at DX or KD..as in $2 or something like that. I have a 52 mm aspheric and a lens that was 42 mm and now it 38 mm. The focal lengths vary. They don't tell you what they are when you order so since they are cheap just order anything that might work.
If you have access to a bench grinder you can grind the lip off a larger one to make it smaller. If one fits but doesn't focus the emitter perfectly (depending on the design of the flashlight) you may be able to screw the head in or out a little to fine tune the focus.
They are fun to play with anyway and you'll instantly see how they work If they don't work with this light keep them around and they'll work with some other light.
I've done 4 lights of differing sizes this way. I had to grind all but one however one uses a plastic aspheric so you can grind it with just a regular hand sander.
This will make your light a dedicated thrower however with a very narrow beam and won't be useful for anything other than spotting things in the distance so it depends on what you want to do with this light.
Yeah, I didn't either, but I just ran across it today looking for something else and I'm like.. "hey, wasn't I looking for a 4x mm part the other day?"
Still haven't found the right regular lens, but you gotta admit this is fun too :P
I ordered a number of different aluminium 42mm smooth reflectors from Manafont a couple of weeks ago in the hope that one would fit. They arrived today and I'm happy to say one dropped in with no mods required, the 46mm retaining ring is exactly the right size to centre the new reflector over the emitter. I may build a new retaining collar to pressure fit the reflector into the head later, but as of now I'm happy with the improvements; better beam quality, a bit tighter focus, all the artifacts are gone and 7 of 8 rings can no longer been seen in the beam shot.
I have not been able to find a 46mm glass reflector. So I will use the plastic one for now until I either grind a 52mm down to size or reduce the entire ID of the head to 42MM. I'm still not sure what the preferred path will be. Either way, it will of course be a project! :)