# Solitaire Tail Cap



## coldsolderjoint (Dec 26, 2005)

Hi, 

Does any body know what the threads on a [email protected] Solitaire Tail Cap are? 

Thanks


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## tvodrd (Dec 26, 2005)

It's a non-standard I measure at ~.45"-30 or 32tpi. With only 4 threads against my gage, I would need an optical comparitor to nail down the pitch. It's close or the same as Arc used on the original AAA.

Larry


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## pbarrette (Dec 26, 2005)

Hi Larry,

I'd been wondering the same thing for quite some time now, then you come along and tell me it's the same as the ArcAAA. I'd never even thought to try screwing those parts together before, but a quick check just now shows that they seem to fit perfectly.

I've got ArcAAA measurements from a previous project:
OD = 0.4475"
ID = 0.4200"
TPI = 32

The ID could be a bit off, but probably not by much.

pb


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## coldsolderjoint (Dec 27, 2005)

cool.. thanks for those numbers.. 

looks like im out of luck trying to find a tap that size. I was thinking of an ultra mini UV solitare.. like 4 button cell batteries and a uv led, like for hotel rooms, you could easily keep it on your key chain. 

Im a noob here on candlepowerforums and just attempted my first "real mod".. i tried to cut down a mini mag to accept a cr2 battery. I know I could buy one here, but I just woulda liked to do it myself. Not trying to create competition or anything. 

I ordered the tap from msc-direct.com and got it the next day. I was impressed. that part worked fine.. but lacking the proper drill bit, I turned to my dremel, and tried to bore out the tube.. it didnt have such great results. two broken bits and the tube got too hot, and the tube bent from the vise grips holding it. 

I again hacked into a second mini mag, this time trying to make a 1 AA mini.. and this one worked pretty good, except that I was barbarian-ish with the hack saw, so it doesnt look great.. the light does function however.. I have plans to cut this one down into a mini mini.. once i order the right drill bit.. Homedepot and lowes both suck around here.. 

I figured since i was ordering the drill bit, i might as well pick up the tap for my next project.. 

say i get some of that two ton epoxy.. and fill up the tube of the solitare, and the threads on the tail cap.. let it harden up, and then i could tap out the tube for 7/16-27, and then use a die to re-thread the cap also to 7/16. 

How do you think the epoxy would hold up?


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## VWTim (Dec 27, 2005)

Do you mind sharing the thread pitch of the Minimag tailcap? I'd like to mini one of mine.


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## pbarrette (Dec 27, 2005)

Hi VWTim,

The Mag-2AA tail is:
OD - 5/8"
TPI - 28

For the threading on other lights, have a look here. This thread is also listed in the sticky "threads of interest" post.

pb


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## tvodrd (Dec 27, 2005)

csj, rather than fill the tube with epoxy, you could buy a 5C collet block and 1/2" 5C collet. Also, 7/16-32 is a semi standard thread and should work on the shortened tube. Thread engagement is only 50% or so but should be fine. 

Larry


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## gadget_lover (Dec 27, 2005)

coldsolderjoint said:


> I figured since i was ordering the drill bit, i might as well pick up the tap for my next project..
> 
> say i get some of that two ton epoxy.. and fill up the tube of the solitare, and the threads on the tail cap.. let it harden up, and then i could tap out the tube for 7/16-27, and then use a die to re-thread the cap also to 7/16.
> 
> How do you think the epoxy would hold up?




The epoxy will not hold up well, but that depends on how often you take off the tailcap. The two ton epoxy is fairly brittle.

The other problem is that you have to make sure there is electrical contact between the tailcap and the body, so take that into account in your design.

Daniel


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## tvodrd (Dec 27, 2005)

csj, the challenge with retapping the shortened tube and rethreading the tail cap is how to hold onto them without gorking them up. The 1/2" collet in a block will do that. For the tail cap, you would be rethreading .447"-32 down to .4375"-32 (7/16-32). It will help to sand the top of the existing threads down to 7/16" dia before you start and use a cutting fluid. (WD40 will work in a pinch.) Tap and die wrenches/holders help too.

Larry


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## coldsolderjoint (Dec 28, 2005)

hey, thanks for the help. So, the collet is just used for holding the tube? Ill still need some material to drill into.

What about some kind of meltable metal? I remember when i was in the boyscounts and making pinewood derby cars, my dad would melt up the lead weights with a torch and pour them into holes drilled in the car. 

If I had a similar metal,like alumaloy (the stuff in the tv info mercials. http://www.alumaloy.net/) I could fill the tube up with that, then drill it out as if it was a solid rod. that is, if it will stick to the aluminum on the tube, and wont ruin the finish. Apparently, it has a melting point that can be reached with a propane torch. But, from what im reading, the rods are exensive and really hard to use. It acts more like solder then welding, so i bet ill have trouble filling up part of the tube. Heh.. no wonder I havent seen this mod done before.

Any one ever use JB weld before?


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## gadget_lover (Dec 28, 2005)

Yes, I've used jbweld a lot. It's not as brittle as 2 ton epoxy, but it will crack if subjected to bending loads. There is a "kwick" version and a regular version. The regular one is less brittle.

For personal use, your UV solitaire might work properly as long as you use it tenderly. 

What I did with mine was to build a small spacer to fill the void left over from the smaller battery.

Daniel


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## tvodrd (Dec 28, 2005)

Having reread this thread 4 times, I'm obviously missing something.  Yes the collet will hold the tube (without crushing it) and head very satisfactorily against the torque required for rethreading them. (If it slips, tighten the collet some more!) In fact, I can't think of a better way. :shrug: You do not need to add material to the I.D. of the tube to tap it 7/16-32 or the head to _reduce_ it to 7/16-32. Your thread engagement on the tube will only be ~50% but will be OK! (they'll have flat tops) You will have to eliminate the threads for 1/8" or so to clear the O-ring on the tail cap. (And still seal, if you're careful.) Daniel, can you enlighten me as to what exactly he wants the epoxy for?  (I reiterate- I've missed something here!)

Larry


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## coldsolderjoint (Dec 29, 2005)

ok, so the tail cap *IS* a 7/16-32? 

the first posts said it was .45-32 

7 divided by 16 = 0.4375

Are you saying that its close enough to work? 

If so, then that is great, will save alot of work. 

sorry bout the confusion, im a newbie, with hand tools. Some day I hope to own a lathe  I gotta stop buying lights.


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## tvodrd (Dec 29, 2005)

You will have to run the tail cap into a 7/16-32 threading die to reduce the .45-32 to 7/16-32. You will need the collet or your vise grips to hold the tail cap while doing so.

Larry


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## coldsolderjoint (Dec 29, 2005)

ok.. i think i got it now.. 

1. cut the tube, tap it for 7/16-32. remove threads for 1/8 " 

2. Sand down the threads on the tail cap (with a dremel?)

3. use a die to re-thread the tail cap to 7/16-32

4. Should work if im good. 

How would you suggest I cut the tube? Would a pipe cutter like those for copper water pipe mar the finish of the light? 

Thanks


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## tvodrd (Dec 29, 2005)

1. yes
2. yes- we're only talking ~.006" down- a few twists in some sandpaper should do it.
3. yes
4. yes
I would carefully mark the tube where you want to cut it, say with a turn of masking tape over the portion you wish to throw away. (Remember, it's a lot easier to cut it off than put it back! Measure twice, cut once!) Next, put it into the collet up to the tape and tighten the collet. Use a hacksaw against the face of the collet, which should give you a square, clean cut. Now tap it. 

Larry


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## coldsolderjoint (Dec 29, 2005)

alright, sounds good.. im going to wait to next week to order the tools (paycheck), and then ill get to work. 

Ill be sure to post pics when im done. 

Thanks for all your help.


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## changsn (Jan 2, 2006)

I just found that my old Solitaire got a leaky battery. I've stripped it and if you would like extra parts, I can send them to you. Let me know your address if interested - no charge! Actually if you want it, maybe I'll put all the pieces back together to ship.
Sam


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## tvodrd (Jan 3, 2006)

Nice, changsn! I won't be around for confused guidance for the next few days. Have to fly to the east coast on business- back on line sat, if the box will boot. (been having HDD problems.) :wave:

Larry (CtrlA, CtrlC  )


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## DCFluX (Jan 5, 2006)

It may be easier and cheaper just to use a SMPS and you wouldn't have to mod anything.


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