# CMG Micro, The smallest CR2 Flashlight in the world



## ma_sha1 (May 28, 2010)

I made this today as a Memorial day gift to myself 


I picked up a CMG infinity, a flashlight that most CPFer had one or more at some point, no one is going to give it a second look anymore.

However, there's a few things that caught my eye.

1. The head is very short, that's a good thing.
2. Many prior mods on upgrading the head with power leds have been done, great potential 
3. The battery tube is pretty fat for AA light, can be bored out for CR2.
4. The thread area can clear CR2 without modding!

That's a lot of good things going at once. So, Long story short, I cut the body in two pieces. 

Grind down the big long tail:






Bored the body tube with Drill/grinder to fit CR2:





Clamped up together, doing my normal JB weld trick 






Several hours later, Making sure it works with CR2 power, yep, works & it's brighter than stock running AA too.





The finished product easily beat my other small CR2 lights in size, even beat the Orb raw NS, 
which runs on smaller 14250 battery (CR2 is 15266, abut 2mm longer than 14250).

*Left to tight:*
CMG Micro CR2, Orb Raw 14250, Jill DD CR2, 47 Mini CR2, Peak Pacific CR2, 47 Ti Mini 123 
& Nitecore D5 (Smallest Piston Drive flashlight in the world) 





Now, how does it compare to previous CR2 record?

The smallest CR2 light record was held by ArcMania's Extreme Micro, which is 43.5mm long. 
http://webcache.googleusercontent.com/search?q=cache:WlQCsaxxmcYJ:www.candlepowerforums.com/vb/showthread.php%3Ft%3D165593+extreme+micro+43.5mm&cd=1&hl=en&ct=clnk&gl=us

Jill CR2 is 52mm long (#2 spot for CR2?). The Orb Raw is smaller measured at 48 mm long, but it's not a true CR2 flashlight 
(There's a earlier version of Raw that runs on CR2, but it was longer, I think it was longer than Jill DD).

Now, the moment of truth:
*The CMG Micro measured in at 42.5 mm, beat E Micro by 1 mm *

I know it's not a lot, but E micro was already such a small light for CR2, there's a reason that it held the record for 
being the smallest CR2 flashlight for so long. ArcMania really didn't leave any room for anyone else to come & play.






For these who are thinking about dust off your old CMG infinity & take this mod a step further. 
The CMG head is about 16mm long, so one can open it up & DD a XPG with RCR2 Li-ion (AW sells 15266 Li-ion). 

There's room for a power LED + short reflector or a small lens, but there's probably not enough room for a board, 
so most likely a DD solution will become your best bet.


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## Kestrel (May 28, 2010)

Very nice. Narrow as well as short. Just out of curiosity, can you provide diameters of your lineup as well?


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## joe1512 (May 28, 2010)

Well done!


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## ma_sha1 (May 28, 2010)

Kestrel said:


> Very nice. Narrow as well as short. Just out of curiosity, can you provide diameters of your lineup as well?




Sure, The diameters are

CMG Micro CR2: 19 mm
Orb Raw: 19 mm (the widest part)
Jillite DD: 20 mm
4Sever Mini CR2 19 mm
4Seven Mini 123: 20.5 mm
Nitecore D5" 20.5 mm


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## paulr (May 28, 2010)

Wait, it's running the stock led and driver? Why stop with a CR2 in that case, instead of an N or even an SR44 coin cell?

What did you do at the tail end--it looks like you cut the tube in the middle, then JB-welded the solid disc (with the old lanyard lug ground off) to the now open end? JB-weld is electrically conductive I guess?

Nice job :thumbsup:


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## scout24 (May 28, 2010)

Beautiful!!!


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## ma_sha1 (May 28, 2010)

paulr said:


> Wait, it's running the stock led and driver? Why stop with a CR2 in that case, instead of an N or even an SR44 coin cell?



For N cell/SR44, you'd want a Peak, the CMG will be too fat, looks funny.
I made a Peak running 1/3 N Lithium Primary, it's for sale, it's even smaller:
https://www.candlepowerforums.com/threads/275856



paulr said:


> What did you do at the tail end--it looks like you cut the tube in the middle, then JB-welded the solid disc (with the old lanyard lug ground off) to the now open end? JB-weld is electrically conductive I guess?
> Nice job :thumbsup:



Not JB weld solid Disk, JB weld is not conductive.
You need to file one end & bore the other, then plug it in place.
JB weld selected locations inside (I do 4 spot-weld) but weld the outside all around for sealing. 

Need to leave enough bare Aluminum contacts for conductivity.
Here is a recent example, you can see the bore out end of one piece before joining together.
Regardless of big or small light, my Cut-em-down's were all done by the same mechanism. 
https://www.candlepowerforums.com/threads/273748
.
.


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## ninemm (May 28, 2010)

Great work as always Ma! :thumbsup: You're build threads are a real treat.


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## ma_sha1 (May 28, 2010)

Thanks man


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## Light11 (May 28, 2010)

Very ,very nice!!:twothumbs


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## kosPap (May 29, 2010)

ma_sha1 you are never getting close to my car...Period!

LOLOLOL
:twothumbshttp://www.candlepowerforums.com/vb/images/smilies/happy14.gif


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## jabe1 (May 29, 2010)

kosPap said:


> ma_sha1 you are never getting close to my car...Period!
> 
> LOLOLOL
> :twothumbs


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## Robocop (May 31, 2010)

I have always enjoyed modding and took pride in the way I made things without fancy tools or a lathe. This is a very slick mod and bravo to you for doing it with hand tools and good old fashioned thinking outside the box.

I am interested in how you joined the sections without using a lathe or making threads. I believe I have a general idea from your pics however would like to know a little more. Did you simply bevel one section and force them together using nothing more than pressure?...and JB Weld?

I am thinking of using one of my very mint Ultra-Gs for a similiar mod and may use this same method. I am also thinking of trying the same method on one of my 2-D Mags similiar to your other thread.


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## ma_sha1 (May 31, 2010)

Robocop said:


> I have always enjoyed modding and took pride in the way I made things without fancy tools or a lathe. This is a very slick mod and bravo to you for doing it with hand tools and good old fashioned thinking outside the box.
> 
> I am interested in how you joined the sections without using a lathe or making threads. I believe I have a general idea from your pics however would like to know a little more. Did you simply bevel one section and force them together using nothing more than pressure?...and JB Weld?
> 
> I am thinking of using one of my very mint Ultra-Gs for a similiar mod and may use this same method. I am also thinking of trying the same method on one of my 2-D Mags similiar to your other thread.



Once cut, one piece is bored out, the the other piece is filed to reduce diameter. The two pieces are then plug into place, it should be a press fit, tight without JB weld. Then apply JB weld at selected locations inside (I do 4 spot-weld) but weld the outside seam all around for sealing. 

Need to leave enough bare Aluminum contacts for conductivity.
Here is a recent example, you can see the bore out end of one piece before joining together. 
http://www.candlepowerforums.com/vb/...d.php?t=273748
.


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## Robocop (Jun 1, 2010)

Thank you for the clarification as I was pretty sure that was the process just never knew it would really work so well. Have you had any issues with long term durability using this process? Excellent work by the way and I have 5 of the CMG Ultras and have been waiting for a reason to take a chance on modding one....this looks like a good excuse to try my luck.

Any way you could show a photo of the drill bit you are using? Do you think it could be done with a dremel tool also?


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## ma_sha1 (Jun 1, 2010)

No issues on durability if the press fit is tight to begin with. 
You won't be able to take it part. 

The only issue is at the filing end, it's difficult to file a perfect circle by hand, I use a Pipe cutter to make a shallow circle first, it helps to align things up. It'll take some practice, but you have 5 CMGs to practice on :laughing:.

For smaller lights, I usually use a step drill & hold the piece with bionic wrench lined with rubber belt while drilling:
dremel should be possible, but I never tried it. Step drill is easy to do, as long as you can hold the piece in place 
tight without damaging the Ano. 








Robocop said:


> Thank you for the clarification as I was pretty sure that was the process just never knew it would really work so well. Have you had any issues with long term durability using this process? Excellent work by the way and I have 5 of the CMG Ultras and have been waiting for a reason to take a chance on modding one....this looks like a good excuse to try my luck.
> 
> Any way you could show a photo of the drill bit you are using? Do you think it could be done with a dremel tool also?


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## David Gretzmier (Jun 1, 2010)

Another nice mod Ma sha ! you know I love tiny lights. if you ever mod DD with xpg and RCR cr2, you know I will buy it...let me know.


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## Chauncey Gardner (Jun 1, 2010)

jabe1 said:


>


 
Looks like Ma Sha got ahold of a Mini Cooper & turned it into a Mircro Coop.

Always enjoy seeing what his imagination turns out.


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## ma_sha1 (Jun 1, 2010)

Chauncey Gardner said:


> Looks like Ma Sha got ahold of a Mini Cooper & turned it into a Mircro Coop.
> 
> Always enjoy seeing what his imagination turns out.



That's real funny 




kosPap said:


> ma_sha1 you are never getting close to my car...Period!
> 
> LOLOLOL
> :twothumbs



Don't let me see you then, cause I'll have to chase you down. 
Before got into modding flashlight, I was into modding cars, 
packed a HKS/Rotrex super charger under the hood of my infinity G35x, 
Supercharger + All wheel drive launch = 0-60 in 4.5 seconds, 
It's the round thing to the right above the red mushroom filter. :devil:




.
.


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## Chauncey Gardner (Jun 1, 2010)

Can't believe you shoehorned that in a G35.

Nice strut tower brace too. Was that custom formed to fit?


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## ma_sha1 (Jun 1, 2010)

Chauncey Gardner said:


> Can't believe you shoehorned that in a G35.
> 
> Nice strut tower brace too. Was that custom formed to fit?



It's a custom piece a guy made on G35 driver forum


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