# Romisen RC-G2 with SSC P4



## Hrvoje (Jan 12, 2009)

Thanks to BessieBenny great review, recently ordered Romisen RC-G2 (actually few of them). I will leave one in stock form, because even with inferior Cree P2 it is still a great flashlight. My intention is to be able to use both AA and 15400 cell in modded form. I had 5-mode buck/boost driver from DX (sku 15880) lying around, which looks ideal for this purpose. I didn't like idea of ruining original heatsink trying to remove glued LED and soldered driver, so I decide to make my own. My heatsink is 0.5 mm larger in diameter then original, so I was able to press fit driver in heatsink without to much sanding (only about 0.3 mm, from 17 mm to 16.7). I could use driver in original shape, but then thickness of the walls would be only 0.25 mm, maybe a little to weak.
LED is SSC P4, USXOH from Kai, with Vf of 3.25 V. LED is glued in place with Arctic Alumina thermal adhesive.
Before I soldered leads to LED, I measured current. From Sanyo AA 2500 mAh NiMh current on high at led terminal is about 0.3 A. Didn't measured mid. and low. At the tail cap current is 1.3 A on high, 0.37 A on mid. and 0.06 A on the low mode.
Unfortunately, I don't have manual settings on my camera, so after many attempts, I didn't achieved useful beamshot at different settings, because there is barely visible difference on the images at low, medium and high output, but in reality difference is very obvious. High is brighter then stock output, medium is like my MiniMag 2AA with TeraLux MiniStar2 LED upgrade, and low is like Solitaire, but still usefull.
So I only showed stock and moddified high output beamshots. Distance is 1 m from white wall. Compared to stock G2, throw is about the same, but spill is much more usefull. Original Cree was a little bit greenish, P4 is more on the white side. Anyway, great flashlight is now even better. I already ordered pair of 14500, with that Lithium power this will be one mighty EDC flashlight. Will post current draw and beamshot when I got that.

Hrvoje


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## Hrvoje (Jan 12, 2009)

More images:


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## 3rdrock (Jan 12, 2009)

Thats cool! :thumbsup:

I like my stock one,if you where closer to me I would have you make me one.


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## Fallingwater (Jan 12, 2009)

I cannot see a single one of your pictures. Is it just me?

Edit: it seems geocities is temporarily unreachable from my location. Oh well.


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## Scott_T (Jan 12, 2009)

Fallingwater said:


> I cannot see a single one of your pictures. Is it just me?



Its just you. 

Looks nice. I just put a Q5 with an 800ma driver in mine and its very very nice. I'm not sure if I want to keep the 5 modes yet. I prefer them for saving the battery but you never know what mode is going to show up when you turn it on.


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## linterno (Jan 12, 2009)

Fallingwater said:


> I cannot see a single one of your pictures. Is it just me?


Neither I. Images invisible..


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## Black Rose (Jan 12, 2009)

Fallingwater said:


> I cannot see a single one of your pictures. Is it just me?


I can see them fine.

Cool mod :thumbsup:


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## kuksul08 (Jan 13, 2009)

can't see pics


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## Hrvoje (Jan 13, 2009)

I don't know where is the problem. Here are direct links:

http://www.geocities.com/hrvojekl/RCG2/RCG2.jpg
http://www.geocities.com/hrvojekl/RCG2/heatsink.jpg
http://www.geocities.com/hrvojekl/RCG2/body.jpg
http://www.geocities.com/hrvojekl/RCG2/heatsink1.jpg
http://www.geocities.com/hrvojekl/RCG2/heatsink2.jpg
http://www.geocities.com/hrvojekl/RCG2/driver.jpg
http://www.geocities.com/hrvojekl/RCG2/heatsink3.jpg
http://www.geocities.com/hrvojekl/RCG2/SSCP4.jpg
http://www.geocities.com/hrvojekl/RCG2/reflector.jpg
http://www.geocities.com/hrvojekl/RCG2/RCG2P4.jpg
http://www.geocities.com/hrvojekl/RCG2/stock_beamshot.jpg
http://www.geocities.com/hrvojekl/RCG2/beamshot_SSCP4.jpg

Hope this help.

Hrvoje


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## Lynx_Arc (Jan 13, 2009)

I get this message. I think Yahoo servers are flakey right now

Sorry, Service Temporarily Unavailable.
The server is temporarily unable to service your request due to maintenance downtime or capacity problems. Please try again later.

Additionally, a 503 Service Temporarily Unavailable error was encountered while trying to use an ErrorDocument to handle the request.


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## supawabb (Jan 13, 2009)

That looks pretty awesome!


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## nanotech17 (Jan 13, 2009)

nicely centered emitter :thumbsup:
sure hope the emitter is driven hard by this driver.
i use the same driver to power my home made drop-ins with K2 TFFC TWOF and surprisingly it can be power up with a single AA alkaline.


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## Fallingwater (Jan 14, 2009)

I can see the pics now. I too like the SSC's floodier beam a whole lot more than the Cree's throwy one. Your mod is very similar to what I did to my L-mini, by the way (coincidentally, it too is about to get one of those drivers).
How did you insulate the positive slug of the SSC?
Good job


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## Hrvoje (Jan 14, 2009)

Thanks. When I glued bare emitter to the heatsink, just didn't press to much to avoid metal to metal contact. Regarding emitter centering, Arctic Alumins cured faster then I expected (it was hot in my room), so centering could be better (error is maybe 0.2-0.3 mm), but there is not visible effect on the beam quality. I'm very satisfied, the only thing that is annoying is mode changing with forward clicky switch.
I just received new driver from DX (sku.7302), looks like a good candidate for replacing original driver in my other RC-G2. Or maybe I should try MC-E? I like mighty LED-s in the pocket lights 

Hrvoje


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## PlayboyJoeShmoe (Jan 14, 2009)

I'm a fellow who prefers beam quality about 80% over maximum throw.

My RC-G2 is cute little critter that is pretty bright. But since it's all about spot it doesn't get a lot of playtime.

Cool mod! When it gets more popular I'll have to see about getting it done to a light or three!


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## Fallingwater (Jan 15, 2009)

Hrvoje said:


> Thanks. When I glued bare emitter to the heatsink, just didn't press to much to avoid metal to metal contact


I'd be worried about lousy thermal transfer if I did this.
On another board I was advised to use some talcum powder mixed with the epoxy/goop. If the two surfaces are flat enough, the talcum dust is enough to prevent conductivity.



> Or maybe I should try MC-E? I like mighty LED-s in the pocket lights


You couldn't drive it at anything like full power without either a massive heatsink (which would defeat the purpose) or forced air cooling (good luck with that  ).

He he, tek sam primijetijo otkud pises.


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## Hrvoje (Jan 15, 2009)

Fallingwater said:


> You couldn't drive it at anything like full power without either a massive heatsink (which would defeat the purpose) or forced air cooling (good luck with that  ).



Yes, I know, but RC-G2 is slightly bigger then average 1AA flashlight. I can make solid cooper heatsink and put some thermal grease between the heatsink and tube. Anyway, I can't drive it at full power from 14500 cell, but some 1.2-1.4 A at the emitter would be more than enough from such a small flashlight. With multi mode driver, full power will be used only for short period.

Hrvoje

P.S. Pozdrav, zemljače. Nas Hrvata svugdje ima . Ima li još koji na ovom forumu?


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## debeli (Jan 15, 2009)

Hrvoje said:


> Yes, I know, but RC-G2 is slightly bigger then average 1AA flashlight. I can make solid cooper heatsink and put some thermal grease between the heatsink and tube. Anyway, I can't drive it at full power from 14500 cell, but some 1.2-1.4 A at the emitter would be more than enough from such a small flashlight. With multi mode driver, full power will be used only for short period.
> 
> Hrvoje
> 
> P.S. Pozdrav, zemljače. Nas Hrvata svugdje ima . Ima li još koji na ovom forumu?



Ima


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## PlayboyJoeShmoe (Jan 15, 2009)

Sounds like fun Hrvoje!


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## Hrvoje (Jan 20, 2009)

Just modded another RC-G2, this time with Cree R2 I took from P60 drop-in module from DX (sku. 14442). Home made heat sink pill is the same as in previous SSC P4 modified G2. Driver is 19 mode from DX (sku. 7882). Pot is so adjusted that voltage at the LED is about 3.15 V, current at LED is about 0.5 A and current draw from the Sanyo 2500 mAh NiMh battery is about 1.6 A. Now this is the real pocket thrower 
I'm curious to compare this with SSC P4 modded G2 intended to run on 14500 cell which is on the way.
Anyway, I compared original P2 with modified P2 and better 5 mode driver (DX sku.7302). Original driver is pretty unefficient, with only about 0.2 A and 3.2 V at emitter terminals, drawing about 1.5 A from the battery. This 5 mode 7302 driver is in fact pretty good, driving good old P2 at 0.56 A (slightly above max. current) and 3.52 V, sucking 1.87 A from the battery (Sanyo 2500 mAh NiMh). Priced at $3.50, this is relatively cheap way to improve stock RC-G2 without to much modding and emitter swapping.
Of course, adding GITD O-ring also improve performance 
I will put some beamshots when I borrow better camera with manual settings.

Hrvoje


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## gunga (Jan 20, 2009)

What do you think of the 7302 and 15880 drivers? Are they really 5 mode only? I've read that the 7302 is rally a 16 mode driver, mislabeled...


Nice mods! Were your G2's all glued?


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## Hrvoje (Jan 20, 2009)

So far I'm very satisfied. My 7302 is 5 mode driver, and 15880 has 19 mode.
On my two G2 nothing is glued except emitter.

Hrvoje


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## gunga (Jan 20, 2009)

Hrvoje said:


> So far I'm very satisfied. My 7302 is 5 mode driver, and 15880 has 19 mode.
> On my two G2 nothing is glued except emitter.
> 
> Hrvoje


 
15880 has 19? You state in the 1st post that it has 5? DO you mean the 7882 has 19 modes and the other 2 have 5 only?


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## Hrvoje (Jan 20, 2009)

Sorry, my mistake, 15880 and 7302 are 5 mode drivers, and 7882 is 19 mode driver.

Hrvoje


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## Hrvoje (Jan 20, 2009)

By the way, maybe someone know where to find 24 mm AR coated lens for RC-G2? I think this mighty little light deserve something like that.

Hrvoje


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## chandelier7 (Jan 22, 2009)

Hi Hrvoje,

Sorry, I can't help with the lens, but these are some very nice mods, thanks for shareing!

I've got a question because I'm about to order some flashlights (also the RC-G2) and also planned to add a different driver.
Did you just set that sku.7302 driver on top of the light's original aluminium tube? Or did you have to sand or decrease it's height in some way to compensate for the added height of the 7302's circuit board?

Hmmm, I hope I'll be able to swap the P2 LED without destroying it against a Q5 (or a SSC like you did ...)

Cheers,
Dominique


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## Hrvoje (Jan 24, 2009)

Hi Dominique, yes I shortened heatsink tube to compensate the height difference of the board.

Hrvoje


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## chandelier7 (Jan 26, 2009)

Sorry, I've got another question... 

Where did you get those GITD O-Rings from?

Cheers,
Dominique


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## AlexGT (Jan 26, 2009)

Hi Hrvoje!

Thanks for sharing your mod, I ordered another G2 from DX and the 7302 driver and I am wondering how are you holding it together since it is not press fit into the heatsink, Are you using Glue? Also did you electrically isolate the top border of the driver that contacts the metal heatsink?

Thanks!
AlexGT


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## Hrvoje (Jan 27, 2009)

Alex, there is no glue, when the heatsink is screwed, driver is firmly pressed between the heatsink and the body, ensuring good electrical contact. Driver upper ring is (-), and this surface must have a contact to the heatsink.
Have a look here:

https://www.candlepowerforums.com/posts/2450062&postcount=7

Dominique, 24 mm GITD O-rings are from DX (sku. 3458)

Hrvoje


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## AlexGT (Jan 27, 2009)

Thanks for the explanation, how do you keep the wires from twisting? Do you twist it in the opposite direction prior to screwing it in Or do you screw it in before pulling the wires for the led thru the holes in the heatsink?


Thanks!
AlexGT


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## Hrvoje (Jan 29, 2009)

Just screwed it in without any problem, led wires were already soldered.
Yesterday arrived 14500 cells, now I have a real pocket throwers, in fact one flooder/thrower (SSC P4) and the true thrower (Cree R2). I also can use AA if I want 
Waiting for better camera with manual settings, will take some outdoor beam shots.
Also arrived one 10280 and one 14250 cells. My plan is to build something like Draco light, but maybe I will just take suitable 10440 and 14500 flashlights and make it shorter. I'm not in the mood for too much lathe work 






Hrvoje


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## vodokotlic (Nov 10, 2009)

Hello Hrvoje!
In the first post you mentioned ordering a bunch of Romisen RC-G2. Were they ordered from online retailer or from some local retailer in Croatia? Only local ad I could find is this one: http://www.njuskalo.hr/oruzje/lampa-romisen-rc-g2-nocni-lov-ribolov-oglas-573930 which is a bit shady (It says it has Cree XR-E emitter but pictures are of first gen Cree P2 version).
Also, if you were ordering online, were there any problems at customs (PDV, carina)?

P.S. I was trying to put this in a private message, but it doesn't work, probably because i'm a new member. If you were to reply via PM, feel free to write in Croatian, I'm using English only for the sake of open forum.


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## Hrvoje (Nov 11, 2009)

PM sent.

Hrvoje


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## kland1234 (Nov 12, 2009)

Nice Hrvoje
so what is the height difference between the cavity where the star was and the height of your P4 mounting surface; how much was the P4 raised?


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## Hrvoje (Nov 16, 2009)

I machined completely new pill for SSC P4 emitter, but the height of P4 is about the same as old Cree P2.

Hrvoje


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