Looks like there are several versions. Can’t do it with just push method with mine.
> push method
You might try this — put a tiny bit of oil inside the tailcap, just around the outside edge of the plastic along the contact with the aluminum.
Just enough that it ‘wicks in’ slightly, much less than a whole drop of oil; a bit with a toothpick should do.
Then pad the tailcap on both ends and set a spacer on top of the green button, no bigger diameter than the green thing, and put it into a desktop vise.
Gently and slowly start to compress it. Add longer spacers as needed since you’re pushing the green thing slowly down into the outside aluminum ring.
Less chance of breaking off the little button that’s under the green thing with steady even pressure — and more pressure.
I only needed to do this once for a press-fit switch — but it worked.
Maybe you could be the second success (grin)
or, at worst, of course, you’ll crush it beyond use …
Hi Tom how did you keep the otmen switch from falling apart during trimming? I have tried quite a few and they all crack in half horizontally
Dunno - seemed to work for me 1st time, but only did one. I know I went real slow and careful - maybe used a rotary tool a little, then small hand file.
Hi Tom, where did you get the U3-1A from? Do you think a U2-1A would be brighter? I read on another thread that U3’s weren’t performing as expected.
I bought qty 3 from IOS on 16mm Noctigons, at the time. Dunno - maybe I got some from the 1st batch and got lucky? I haven't bought anymore since because of all the talk, tests, etc., coming out. I have no clue what to do or recommend at this point. The loss's some incurred of blowing the LED's, or getting less output than U2's is really causing me to hesitate. It's hard because the sources that sell them aren't saying much, and hard to tell what's relevant and real and what's not.
I'm getting this info on the U3's not only from BLF thread posts, but in private pm's - it's scary...
The Switch I used in the ZeusRay:
Ok, I did confirm I bought a total of 4 of these Omten switch's: fasttech.com-omten-15a-250v, ordered back in August. I still got 3 on-hand, so this makes sense and it looks to exactly match.
Finally!!!
These are the tools I used. Pull out the rubber button by force. You will be able to see the switch now. Give it a few taps with a screw driver on plastic retainer, in order to push it out. There will be no visible damage from the exterior with this method.
This shows the white plastic version. The tailcap is actually a different design - shorter than the clear plastic version:
This is the U3 1A mounted:
The Omten switch from FastTech used:
Other type on left, one used on right:
Close-ups:
Thanks for the pictures, especially the brown reflector i hadn’t seen that one on blf before.
Ok, i guess it fastech omten i will try then, good thing i hadn’t ordered yet.
I got mine out easy now, when i knew how high of edge it had i could much easier estimate the amount of force i would need to pry it out without damaging it.
Did you drill those holes in the pill for the noctigon retention screws?
And have you tried a dedomed xm-l2 in the zeusray or any other zoomie? will you lose a lot of flood? because thats one thing i like about this one stock.
- Yes, drilled and tapped the holes. I do this quite often, specially with zoomies that don't have a reflector to hold down the LED/MCPCB.
- de-domed LED's in aspherics won't lose any flood area (I don't think), but will lose lumens, so the brightness of the flood area will be reduced. I say "I don't think" because I hadn't noticed and don't think anyone else mentioned this in the past for aspherics like the T20. Of course it should double the throw (kcd #, not distance) when fully zoomed out.
My 2nd modded ZeusRay I'm just starting one, shown below, I will do a de-domed XM-L2 for, so should have a good comparison.
Just showing how the custom board fits - like a glove... -->
Nice, the single sided blfdd fits perfectly just like i thought it would, where did you get one?
And if you build them yourself, Can i buy one 
i don’t know anyone who sells those yet and i not really there yet to start building the drivers myself, i will hopefully get there after i get some proper fully tricked out flashlights under my belt.
In any case i am very interested in what the numbers are going to be
Ahh, I buy the boards from OSHPark and buy the parts from DigiKey - been doin it a while, maybe since the beginning here on BLF. I started doing Nanjg boards with the "comfy" FET mod before BLF'ers went with OSHPark designs. But these are the first boards from wight's design I've tried. If you have no-one over there to do it, I could build/test/send you one, but dunno bout Sweden shipping. Think someone mentioned recently that's it's fairly cheap. If you know, or can find out, and ok with you, I'm think'n I could charge you $12 plus shipping. Best to pm me though with all the details: firmware options/modes, etc. First run of 3 I built last night, I'm using the extra cap for OFF time memory with special firmware.
If you haven’t already dedomed the led you are going to use it would be interesting to know the numbers before with the single sided fet driver and after you dedomed it.
Any advice how to get the bezel off without destroying it?
I have no strap wrenches and mine is stuck fast. 
Just press against and unscrew with a rubber mat, on top floor or hard surfaces. I think someone mention carpet works too.
I use these and keep a pair handy right at my bench: http://www.homedepot.com/p/Firm-Grip-Latex-Coated-Cotton-Large-Work-Gloves-5083-48/100123073. Great "stickness" level. I've been amazed how much more twisting leverage I can get.
I just put the head on my carpet and twisted and it opened easily thanks to someones tips here, the bigger problem was there was no holes on the pill so i had to drill two holes to get some leverage to twist out the pill from the body.
I think the second batch was a little bit different, because all the pictures from the first i saw seamed to have those originally.
Have anyone tried this in the zeusray Glass lens 28mm
http://www.dx.com/p/glass-optics-for-flashlights-28mm-5297
My zeusray lens is 28,15 x 8mmH with an 21,51mm “dome”
The bottom lip that the lens is resting on is 25,15mm so an optimal dropin glass lens would have to be bigger than that, and i haven’t found any other than 28’s, the closest is one at kaidomain thats 23,9mm,
http://www.kaidomain.com/product/details.S020954
but i think it could possibly fit if you would fit the o ring under the lens instead of between the bezel and lens, or find a slightly wider o ring.
I think a 28mm should fit if i open up the bezel a bit (3 mm so a lot filing), i think i saw something to that effect in one of the zeusrays threads a while back.
here are some more i found thats 28mm
http://www.ebay.com/itm/High-Power-LED-28mm-convex-lens-optical-glass-red-green-blue-white-led-lens-/120941581074
http://www.kaidomain.com/product/details.S020648
http://www.kaidomain.com/product/details.S004592
http://www.ebay.com/itm/2-pcs-High-Power-LED-28mm-convex-lens-optical-glass-led-lens/180933104270
http://www.ebay.com/itm/1-pc-High-Power-LED-28mm-convex-lens-optical-glass-led-lens-/170881804770
Is there any better glass lenses that may fit? and you guys that have upgraded the cheap plastic to glass like this in a zoomy whats the effect? more lumens? more throw? and how much more if any can i expect from stock.
I really have no base for an estimate at all it would be nice to get an idea about it.
Oh boy, the very little I've played with aspheric lenses, I found it very frustrating... You'll have all sort of mounting and focus length issues. Fitting is only part of the issue. Could get lucky, or maybe it can be calculated out.
I have opened up a lot of bezels to take the larger lens.
Great upgrade if you have access to a lathe.
Just know that hard anodize is really hard on the boring bar bit.