Pimping-out your own Nuwai Q-III tailswitch!

milkyspit

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PIMPING-OUT YOUR OWN NUWAI Q-III TAILSWITCH!

For months (and months, and months...) I've wanted to post a "howto" guide to pimping-out the tailswitch in Nuwai's Quantum-III (a.k.a. Q-III, QIII, Q3... plus OMBU and many more) flashlight. This is a really cute little light with good ergonomics in general and lots of modding possibilities. In fact, the Milky labs have lately become more of a pimpadelic emporium! /ubbthreads/images/graemlins/yellowlaugh.gif I have been, and continue to mod (oops, pimp out) these little puppies on behalf of all sorts of CPFers.

This particular post, however, focuses on the task of transforming the tailcap on the Q3 from a simple on-off reverse tactical clicky that cannot stand on end due to the protruding rubber boot... to a dual stage (low-off-high-off) clicky with rubber boot recessed into the tail so the Q3 can stand upright. A number of folks have purchased the dual stage switches from me in the past couple months, and this guide will help them mod their Q3. (Incidentally, I've still got some switches available... PM if you need some.)

Let's begin, shall we? /ubbthreads/images/graemlins/wink.gif

First, of course, you'll want to unscrew the tailcap from the Q3 flashlight. Here's the object of our pimping, in its pre-pimp, or stock form. Yes, I know this is trivial, but ya gotta start somewhere! /ubbthreads/images/graemlins/grin.gif

Stock Nuwai Q-III Tailcap
image-cpf-nuwai-switch-howto-01-before.jpg


Inside the tailcap, if you look closely, you'll see a transparent threaded retaining ring with a spring rising from its center. Notice that the ring itself has two notches on opposite edges, at roughly the 3 o'clock and 9 o'clock positions in the photo...

Looking Into the Stock Tailcap, At the Threaded Retaining Ring
image-cpf-nuwai-switch-howto-02-inside.jpg


A small pair of needlenose pliers and a gentle touch will unscrew the retaining ring with no damage. It's not glued or otherwise locked in place, so it should simply unscrew then come out completely.

Unscrewing the Internal Retaining Ring
image-cpf-nuwai-switch-howto-03-pliers.jpg


Voila! /ubbthreads/images/graemlins/party.gif At last you've got the retaining ring out of the tail, and now we can see the back of the circuit board to which the switch is attached. You'll see! /ubbthreads/images/graemlins/smile.gif

Tailcap with Retaining Ring Removed
image-cpf-nuwai-switch-howto-04-ringout.jpg


That pesky little circuit board is a bit tricky to dislodge! Here's how I do it (shown in the next photo)... hold the board INSIDE the tailcap with the index finger of your left hand, and press the rubber boot INTO the tail using one of the fingers of your right hand. The finger inside the tail needs to keep the board wiggling a little one way or the other, but not too much or the board will get stuck. Just keep pressing with the right finger, and wiggling with the left finger, and eventually the board, switch, boot and all will pop out!

Removing the Board... the Two Finger Method!
image-cpf-nuwai-switch-howto-05-finger.jpg


See how the boot is not sitting inside the tail? The switch assembly is just about out. Keep going!

Tailswitch Assembly Partway Removed From the Tail
image-cpf-nuwai-switch-howto-06-partout.jpg


It's out! If all went well, this is what the guts of your tailcap look like...

Tailcap Degutted
image-cpf-nuwai-switch-howto-07-allout.jpg


Turning our attention to the threaded retaining ring, we'll need to remove the spring from it temporarily. To do that, notice the slot in the center of the clear plastic, and the hook in the center of the spring. Rotate the spring until hook lines up with slot, then remove the spring. You might need the needlenose pliers to help you rotate the spring... sometimes it's pretty difficult! Just don't break anything in the process. /ubbthreads/images/graemlins/icon15.gif

Threaded Ring with Spring Removed
image-cpf-nuwai-switch-howto-08-nospring.jpg


The rubber boot sits atop a hard plastic frame. Both should lift off the switch itself easily.

Rubber Boot and Hard Plastic Lifted Off the Switch
image-cpf-nuwai-switch-howto-09-oldswitch.jpg


Next we'll have to remove the stock switch from the board. Here's what the board's underside looks like, for reference. Pay particular attention to that solder "smudge" toward the bottom edge... we'll be coming back to that later...

Underside of the Switch Circuit Board
image-cpf-nuwai-switch-howto-10-underside.jpg


Now flip the board upright and snip the leads of the stock switch as close as you can to the board itself. I find that snipping the leads in this way is much easier than trying to desolder the switch, but either technique ought to work. Once snipped, the stock switch should come off the board easily!

Stock Switch, Snipped!
image-cpf-nuwai-switch-howto-11-noswitch.jpg


The dual stage switch is identical in side to the stock one, and actually feels like it's higher quality in construction. It just feels right.

But it's got a problem... the leads extend too far out to fit inside the tailcap! So gently, ever so gently, straighten the three leads, then fold them downward as close to the switch body as possible. Here's a comparison of before and after rebending the leads...

Leads Before (left) and After (right) Rebending
image-cpf-nuwai-switch-howto-12-foldleads.jpg


One interesting quirk is that the Q3 board is already designed for dual brightness operation! Notice how it's got three holes aligned with the three leads coming from the switch. But the leads are too long, and will have to be clipped shorter so they JUST reach the circuit board itself. Don't worry about getting them THROUGH the holes on the board... a solder attachment from the topside will suffice.

Leads Aligned With the Three Holes
image-cpf-nuwai-switch-howto-13-positioned.jpg


Pre-tin both the solder pads on the board, and the three leads themselves... that'll help form stronger connections. Now position the switch and one by one, melt a little more solder so it flows down the lead and into the hole. Take your time and do this step right, as you'll need good connections to ensure reliable operation.

Dual Stage Switch After Surface Soldering to Board
image-cpf-nuwai-switch-howto-14-switchon.jpg


Oops! /ubbthreads/images/graemlins/grinser2.gif Notice one more thing in the photo above. See the two little solder dots in the foreground, next to the bottom edge of the switch? Those are the same connections that were bridged on the board's underside by that solder "smudge." You now have a choice of how to attach resistance for the low beam: either solder a couple surface mount resistors flat against the underside of the board in place of the bridge... or solder a conventional resistor to these two little solder dots (which are actually holes) on the topside. If you choose the latter, you'll need to protect the resistor itself from getting scraped against the sides of the tailcap during reinstallation... in this case, I'm using a small piece of heatshrink tubing to protect the resistor.

Conventional Resistor Soldered Upright and Covered With a Protective Jacket of Heatshrink Tubing
image-cpf-nuwai-switch-howto-15-resistor1.jpg


That solder bridge on the underside of the board will need to be melted away regardless of which type of resistor you use... otherwise you'll short out the resistance and end up with two high beams! /ubbthreads/images/graemlins/ooo.gif

Solder Bridge Removed on Board's Underside
image-cpf-nuwai-switch-howto-16-resistor2.jpg


Once again we turn our attention to the threaded ring. When we recess the switch boot, that'll force everything else in the tailcap to move inward, and there's usually not enough space remaining for the 123 cell! To resolve this dilemma, I take a Dremel with a tiny cutting wheel and slice the ring in half as shown... note that you'll also need to make two new notches with which to tighten the ring (those are also shown).

Threaded Ring Split in Half
image-cpf-nuwai-switch-howto-17-cutring2.jpg


Now find an O-ring that'll fit inside the tailcap... if you can't get an exact fit, I've found that a slightly large O-ring is preferable to a slightly small one. Just cram it down there as best you can, keeping it pressed out to the edges of the tube... then press the rubber boot and hard plastic frame back into the tail. If should extend out the back far enough to press with a finger, but still be recessed enough to stand the tail upright.

O-ring, Rubber Boot, and Tailcap
image-cpf-nuwai-switch-howto-18-oring.jpg


Next, wiggle the board back into the tailcap VERY gingerly! You don't want to short out the switch leads against the sides, strip the enamel off the resistor, etc. Just take it steady, and it should go in fine.

Circuit Board Replaced In the Tailcap
image-cpf-nuwai-switch-howto-19-boardin.jpg


This is what a recessed switch boot should look like...

Tailcap, Recessed!
image-cpf-nuwai-switch-howto-20-sideboot.jpg


Finally, attach the spring to the cut-down threaded retaining ring, giving a little twist to lock the hooked part in... then thread back into the tailcap. Put the modded tail on your Q3, and fire it up! You're done! /ubbthreads/images/graemlins/grinser2.gif

One final note: like many folks, I initially wanted a switch that would give me low-high-off, then repeat, but the low-OFF-high-off (then repeat) was all I could find. Since then, I actually prefer this arrangement! That's because it's more consistent. A single click will always turn the light on or off... and once the light is on, a double click will always toggle between the low and high beams. It's a little like having a poor man's Arc4+ or one of its descendents! /ubbthreads/images/graemlins/smile.gif
 

AvroArrow

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Jan 21, 2004
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290
Location
Vancouver, BC
[ QUOTE ]
what resistor is recomended?

[/ QUOTE ]

If I recall correctly, Milkyspit recommended two 10ohm resistors in parallel to give 5ohms total resistance for the stock circuit. I tried two 20ohms, 15ohms, 10ohms, and found that for me, two 15ohms (7.5ohms total) is perfect. 5ohms resistance is too bright for me, it's dimmer than full power, but not that dim. 10ohms is ArcAAA brightness, too dim. 7.5ohms is about twice as bright as ArcAAA, so it's perfect for me, but YMMV.

*EDIT* Oh yeah, forgot to mention that these resistance figures/observations only apply when using a R123. I didn't try the different resistances with a regular CR123 primary cell.
 

Marc

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Feb 27, 2003
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Location
Quebec, Canada
I've used both 5ohms & 10ohms on R123. 5ohms is way too bright and the light gets hot pretty quickly. For me, 10ohms is the way to go on R123. Can't remember how 10ohms compares against an Ultra-G, but it's 2-3x brighter I guess.
 

AvroArrow

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Jan 21, 2004
Messages
290
Location
Vancouver, BC
[ QUOTE ]
I believe its a #10 o-ring that works?

[/ QUOTE ]

I think it was actually a #21 O-ring at Home Depot, but I may be wrong. Either way, Canadian Home Depots don't carry any o-rings that fit. If you really can't find them locally (like me), you can get ones that fit from Lambda. /ubbthreads/images/graemlins/grin.gif I was rummaging through my flashlight stuff, and found that the 5/8"x1/2" retaining o-ring that Lambda provides with his older pill drop-ins happens to be a perfect fit. Lucky for me, I was able to order a bunch with my MJLED order.

And kudos to Milkyspit for such a nice tutorial. Wish I had read this before modding mine. /ubbthreads/images/graemlins/grin.gif I actually ground down the prongs of the switch with my Dremel (I don't have a file) until they were narrow enough to fit through the 3 holes, and then soldered them. The ground down prongs looked pretty ghetto afterwards, but it works. /ubbthreads/images/graemlins/blush.gif
 

milkyspit

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Sep 21, 2002
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Thanks for all the comments, folks! /ubbthreads/images/graemlins/blush.gif

PMs replied for everyone that sent one... uh, I think! /ubbthreads/images/graemlins/icon15.gif

Will (wquiles), yes, the double mode switch is still reversed. I don't think we'll find a dual brightness switch for the Q3 that ALSO handles momentary on at both brightness levels... it would actually be a pretty complicated part! (Remember, these switches are mechanical.) That's one area where a microcontrolled switch would be handy, though at greater complexity and overall cost.

I did post in my original "pimped-out" thread about an idea of mine to take two pieces of copper foil and space them with a thin piece of rubber, or perhaps some weatherstripping foam, so they would be pressed together when the user started to push the tail to click the pushbutton. You could get a momentary high OR low in this way, but not both.

Bill (bwaites), I think goldserve answered your question: "Milky has the switches for sale and I have 26 more switches as well. PM either of us."

Chevrofreak, AvroArrow, and others, as far as resistance selection, here's what I've found...

Q3 with STOCK CIRCUIT on PRIMARY 123 cell: 5 ohms
Q3 with DORCY 1AAA CIRCUIT on PRIMARY 123 cell: 10 ohms

As far as rechargeable R123 Li-ion cells, I'm not exactly sure what to tell you as I haven't done that many mods optimized for the rechargeable cells. I'd start with the values given above, and tweak things from there. One suggestion, though... choose a value that makes the low beam a little brighter than what you want on a fresh cell, because it'll get dimmer when the cell is nearly depleted. If you start high, hopefully you'll end up pretty much where you wanted to be in terms of brightness!

Also, for maybe $6 you can buy big bag of assorted resistors from Radio Shack. If you open the Q3 tailcap and connect the bottom of the battery to some exposed metal of the battery tube using a resistor, that'll show you what a low beam would look like with that resistance. In this way you could choose EXACTLY the brightness you wanted as a low beam. Once you know the proper resistance, all you need to do is solder it to the board.
/ubbthreads/images/graemlins/thumbsup.gif

NetMage, I have no idea what a #10 O-ring even is! I just go to the local hardware store with a Q3 and visually select the best choice. Is there a guide somewhere that explains what #10 and these other codes officially mean?
/ubbthreads/images/graemlins/confused.gif

One Forgotten Tip! Sometimes I gently sand the corners of the replacement switch down just a bit... this makes it fit into the tailcap tube far easier! Another CPFer PM'd me a couple weeks back to mention that he had done the same thing! So if you have difficulty getting things back together, that might be worth trying. /ubbthreads/images/graemlins/smile.gif
 

chimo

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Sep 16, 2004
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I just did this mod with my Q3. Stock circuit with a TW0J. I used two 10 ohm surface mount resistors in parallel. I didn't have to cut the retaining ring. I dremelled the switch legs to make them through hole.

My battery current readings were:
Low 290 mA
High 740 mA

The battery wasn't fresh (2.95V resting).

A nice and simple mod.

Paul
 

milkyspit

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A Dremel is your friend... highly recommended for all modders, and even would-be modders... heck, ANY flashaholic! /ubbthreads/images/graemlins/grinser2.gif

Just be careful... it's easy to become a Dremelholic, too, and the company sells an infinite number of tips and attachments to feed your habit! /ubbthreads/images/graemlins/ooo.gif

I just PM'd somebody with a few extra tips on installing the "pimped-out" switch in the tailcap... thought I'd share with the group...

[ QUOTE ]
What To Do If The Light Doesn't Work. (Partial Guide.)

Are you using surface mount resistors? If not, then be VERY careful not to scrape the heck out of the resistor while reassembling the light!

Here are some more little tricks that come to mind...

1. That little bent piece of wire that sticks up from the board is supposed to press against the sidewall of the tailcap. Sometimes it gets bent too far inward or comes loose from its solder blob, and will no longer make contact. Make sure it's soldered firmly to the board, and bend it outward enough to press against the sidewall to fix it.

2. If it makes reassembly easier, you can sand down the corners of the switch a little to make them less "pointy"... that lets the switch drop into the tailcap with very little effort. (But remember what I said in #1 above about that contact wire!)

3. Sometimes I wrap plumber's tape (that white teflon pipe tape from the hardware store) a few times around the switch, resistor and all... everything EXCEPT the contact wire, behind which I tuck the tape so it won't come undone. This gives enough insulation (plus slipperiness to boot) to protect things during reassembly.

4. It's best to test the switch assembly BEFORE popping it back into the tailcap. Use the continuity test function on your DMM.

5. Also check the light itself with the tailcap off, by touching a wire from battery to exposed metal on the battery tube... just to make sure your light didn't somehow die, and you're trying to solve the wrong problem! /ubbthreads/images/graemlins/icon15.gif

[/ QUOTE ]
 

chimo

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Sep 16, 2004
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Yes, Dremel-type (mine's not actually made by Dremel) tools are like microwave ovens - you don't know how useful they are until you have one. /ubbthreads/images/graemlins/smile.gif

Some further advice on the mod:

Ensure you bend the switch arms as close to the switch body as possible. There's not much clearance between the switch and the tailcap housing - inadvertent contact between the switch legs and the case is easy (but undesirable /ubbthreads/images/graemlins/ooo.gif) to achieve. If they contact, the switch shorts out and the light stays on. (ask me how I know /ubbthreads/images/graemlins/blush.gif)

If you use SMT resistors, be careful not to add too much solder. There is a ring at the base of the clear retaining ring that is supposed to rest on the PCB. Ensure that the resistors are flat enough so that they do not become the contact point for the retaining ring. Same for the switch if you use the through-hole method. (the dremel tool comes in handy here).

Paul
 
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