Romisen Rc-G2 - Getting the most out of it

geek4christ

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EDIT: Please note, this post should have been post #7, and user Casebrius's first post should have been the original. There was a slight date issue with the forum after it was moved, so that's why this appears to be the first post.

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The stock board is ~15mm.

IMGP0534.jpg


You can get a 16mm board and make it work one of two ways though.


  1. Carefully file 1mm from the edge of the board
  2. File, sand or dremel about 1mm from the bottom of the pill. Then use the shorter pill to screw the board down onto the contact ridge of the flashlight body.
I used option 2 myself in my RC-G2 recently. I can't remember exactly where I got the idea but it was definitely from someone with more ingenuity than myself.

I used a Cree Q5 emitter and this driver from DX, and bypassed the modes on the driver by soldering the negative lead to the rim. This board delivers about 700 mA to the emitter when powered with a good AA NiMH, so thermal epoxy is a good idea.

If you want it brighter then your 14500 cell with that driver you linked should do a very good job. Thermal epoxy will be a necessity at that drive level, though.
 
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Been waiting and waiting for sku.7880 to get back in stock. It was 10/11 and now its 10/15

Is it necessary to use epoxy or will pressure from the reflector do with thermal grease? Maybe with some kind of compressable material formed as a washer?
 
Been waiting and waiting for sku.7880 to get back in stock. It was 10/11 and now its 10/15

Is it necessary to use epoxy or will pressure from the reflector do with thermal grease? Maybe with some kind of compressable material formed as a washer?

A foam washer might work, Scott_T. I think there would be a possibility of the star moving around on the pill and getting off center, though. I'm not sure if thermal greases ever really set up enough to hold it in place.

A thermal glue like this should work though. I believe I remember seeing someone here say that stuff sets up pretty well.
 
A foam washer might work, Scott_T. I think there would be a possibility of the star moving around on the pill and getting off center, though. I'm not sure if thermal greases ever really set up enough to hold it in place.

A thermal glue like this should work though. I believe I remember seeing someone here say that stuff sets up pretty well.

I'm thinking of future upgrades being easier plus I dont want the extra expense of having to buy glue. I dont think keeping the led centered will be a problem seeing how the reflector comes down around the emitter on them, not like mine came centered that great anyhow from the factory.
 
I did exactly what geek4christ explained.

Wait for the 7880 board they work great.

I thought the Group changing would bother me.
It works very well, 3 seconds to change to the next level before it locks the current level into memory.
I use Group 1 thats Weak/Low/Med/High/Ultra Low(Standby)/Beacon
When you stop on Ultra Low it will flash off/on after 5 sec.
Turn off at this point and you move to Group 2... or wait another 3 sec. and it stores Ultra Low as current level in Group 1.
Getting from Group 2 to Group 3 and Group 3 to Group 1 just wait on High for the 5 sec flash.
 
excuse my ignorance - after removing old board from pill, the new board is put in and soldered to side of pill right? Then connect wires to the LED + and -? I'm new to modding and not an electrical engineer (Mechanical). Thanks
 
You might be able to direct drive the Cree XR-E too, but that would be overdriving the LED.

I don't remember what size boards the RC-G2 uses, do you have the measurements?

Actually I have done just that. It wasn't originally planned that way, but that is how it worked out. So I have a Q5 with the stock board jumpered for direct drive to the led. With a protected blue Trustfire 14500 the highest current draw I have seen is 1.4 amps fresh off the charger but this quickly drops. I have used the light off and on for about 2 months now and it is a real pocket rocket. I never did post about it because I figured people would poo-poo it, unregulated and such. It could be done with an AMC driver, but honestly mine is holding up well. Accidently turned it on in my pocket and didn't notice till my butt started burning :). Had to be at least 20 minutes running and the light took it great. I just wish the threads had annodizing to lock it out. I wrapped the threads in kapton for a poor man's lockout, but tape is quickly getting shredded. It just blows away my other G2 with a Q5 running on the stock board. I imagine forward voltage of the led is a factor here.
 
Actually I have done just that. It wasn't originally planned that way, but that is how it worked out. So I have a Q5 with the stock board jumpered for direct drive to the led. With a protected blue Trustfire 14500 the highest current draw I have seen is 1.4 amps fresh off the charger but this quickly drops. I have used the light off and on for about 2 months now and it is a real pocket rocket. I never did post about it because I figured people would poo-poo it, unregulated and such. It could be done with an AMC driver, but honestly mine is holding up well. Accidently turned it on in my pocket and didn't notice till my butt started burning :). Had to be at least 20 minutes running and the light took it great. I just wish the threads had annodizing to lock it out. I wrapped the threads in kapton for a poor man's lockout, but tape is quickly getting shredded. It just blows away my other G2 with a Q5 running on the stock board. I imagine forward voltage of the led is a factor here.

How do I direct drive it? Sorry => NOOB!
 
How do I direct drive it? Sorry => NOOB!

That just means that he's completely bypassing the driver circuitry to deliver the current straight from the battery. So doing that, the output won't be regulated but will gradually decline as the voltage of the battery sags. Many people dislike unregulated lights, but there are several rechargeable battery options out there that deliver an almost-flat discharge curve anyway.
 
How do I direct drive it? Sorry => NOOB!

First of all, one caveat, I won't guarentee that the led won't burn up, although mine has been fine I try and run it in somewhat short burts. And always use a protected battery. And of course it won't work on AA batteries anymore.

The hardest part is the disassembly. Unsolder the leads to the emitter, and pry the led off the aluminum pill. Find a finish nail or something to push down through the holes and drive the circuit board out of the bottom.

As I recall the boost circuit is regulated on the positive side, simply solder a wire to the positive battery contact. Put the "driver (now just a battery contact) back in place, pushing the leads up through the pill. Leave them about 1 inch longer than needed. I took my new Q5 on round MCPB and propped it on the pill with 2 toothpicks. Solder in place. Then I dabbed Fuji heatsink glue under, feed the wires back down, and glue in place. I use the same toothpicks to push down on the MCPB for about 5 minutes.

*edit* I have taken some beam shots of this, but I am trying to find a free html wysiwyg editor before posting. Still haven't found an editor, hosted at google for now.

Not too good at manual photo's yet, all shots ISO fixed at 100 F-stop at 2.8 but exposure time varies, couldn't figure out how to fix it :(

RC-G2 modded is always on the right, ceiling shots from approx 5 feet.
RC-G2stockvsDDlithium.jpg

RC-G2 stock on eneloop vs RC-G2 Q5 direct drive from lithium 14500.
RC-G2modvsNitecoreDX-10alks.jpg


VS Nitecore DX10 on eneloop

RC-G2modvsP3DTurbo.jpg

VS Fenix P3D Q5 on turbo.
 
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That just means that he's completely bypassing the driver circuitry to deliver the current straight from the battery. So doing that, the output won't be regulated but will gradually decline as the voltage of the battery sags. Many people dislike unregulated lights, but there are several rechargeable battery options out there that deliver an almost-flat discharge curve anyway.

Thanks, how do you actually do it?
 
What could I put in a RC-G2 to maximize output? Would a P7 run with a 14500 in this host? If so, what board would be suggested for it. If a P7 isn't suggested, what is the next best in line for max lumens? I'm not looking for a light that will be run for more than five minutes in most cases. Just curious if anyone has done this mod. I have 2 14500's that need a home.
 
If you don't mind punishing the 14500, you can probably direct drive the P7. No driver needed.

The switch might not handle the voltage and current though.
 
Protected 14500 cells will not get the P7 to light because it will draw too much amperage in Direct Drive.
Unprotected cells will draw 2.8a thats over 3C, i think that would be :poof: :eek:oo: dirt:sleepy:
IIRC 1.5a is max amp draw on a 750ma Li-Ion cell
 
Would an R2 or Q5 be better suited? If so, could you suggest a board for either of them. I'm not to edumacated about boards. I'd prefer something from DX since I need to order some other things from them. Thanks
 
You might be able to direct drive the Cree XR-E too, but that would be overdriving the LED.

I don't remember what size boards the RC-G2 uses, do you have the measurements?
 
ressurecting an old thread on an underated light.

Has anyone an idea about how to get a smooth reflector for this thing? its already a good thrower, and Smo reflector would really put it right up where with the best.

any ideas on how to polish the existing reflector perhaps?

Crenshaw
 
ressurecting an old thread on an underated light.

Has anyone an idea about how to get a smooth reflector for this thing? its already a good thrower, and Smo reflector would really put it right up where with the best.

any ideas on how to polish the existing reflector perhaps?

Crenshaw

I asked for a smooth reflector about 1 yr ago... no luck..
 
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