Romisen RC-N3 with R2 (with pictures)

superpila

Newly Enlightened
Joined
Jan 21, 2009
Messages
73
Location
London (UK)
I've just finished a quick and easy mod to my Romisen RC-N3, and thought it would be nice to share it with you.
In the beginning I had purchased this flashlight because I meant to install a new 1.0A driver and an R2 in it, replacing the 0.6A driver and the P4. When the flashlight arrived, I understood that this operation was far from being easy, because the P4 was nastily glued to the heatsink, and that was not the only hurdle. Accessing the driver was going to be even harder.
I tried to go another way, and started from a P60 Drop-in: I noticed that once you have removed the reflector, the drop-in is only slightly fatter than the heatsink+led+driver block of the Romisen, so I decided to stuff the entire dropin inside the flashlight head. I used a single mode dropin from DX, sku.11836, but of course any similarly shaped dropin should work.

Quick howto:

1)Unscrew everything that can be unscrewed, both from the flashlight and the dropin. You should end up with the following:
img3925.jpg


2)Get rid of the external spring and the reflector (first and third object from the right). You won't be needing it. Also you can throw away the P4 block (second object from the left)

3) Protect the R2 bin: I used a small piece of paper and taped it on the heatsink.
img3926.jpg


4) Now it's Dremel time! Get rid of the threads on the dropin. This is the most delicate part of the process: you must try to be as "cylindrical" as possible. Also, the finished dropin must be small enough to fit in the romisen head, yet it must fit tightly. In order to accomplish this result, check FREQUENTLY that you've not dremeled too much, simply trying to push the first part of the dropin inside the Romisen's head. Also, particular care must be taken in checking the the led stays centered in the dropin (that is, try to dremel evenly around the dropin surface).
One last piece of advice: the dropin gets warm while you dremel it. Don't let it become hot or you can damage it. One good way to achieve this is to use your bare fingers to hold the dropin: your thumb suffers the heat much more than it, so you immediately understand when it's time for a short pause to chill down;-)
img3932d.jpg


5) Enjoy the finished work. It's now safe to remove the protection from the emitter.
img3933.jpg


6) Use thermal compound to fill in the fins in the threaded part of the head. Use a finger to make sure you spread it evenly.
img3934.jpg


img3935.jpg


7) Plug the dropin in. If you've done a good job in dremeling it, it should fit in tightly.
img3937.jpg


8) Screw the Romisen head back in, and check that the emitter is well centered in the reflector.
img3940.jpg


9) Done! Check the result.
img3941w.jpg



Beamshots (1 meter from the wall):

Fenix PD20 RCR123 SMO on Turbo on the left. Modded Romisen RC-N3 RCR123 on the right:
img3961g.jpg


Fenix PD20 RCR123 SMO on Turbo on the left. Modded Romisen RC-N3 RCR123 on the right. Underexposed:
img3958r.jpg


Umodedd Romisen RC-N3 on RCR123 on High on the left, Modded Romisen RC-N3 on RCR123 on the right:
img3955ypv.jpg


Umodedd Romisen RC-N3 on RCR123 on High on the left, Modded Romisen RC-N3 on RCR123 on the right. Underexposed:
img3957z.jpg



Overall, I really like the new flashlight. One nice thing about the dropin I used is the wide range of voltages supported. This means that I can use it with a single RCR123, or use two 14500 with the 2xAA body if I want better runtime. Also, the Romisen reflector produces a very nice beam pattern, with reasonable throw yet useful spill.

My next mod, using the same procedure, will be a Romisen multimode MC-E :)
 
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kramer5150

Flashaholic
Joined
Sep 6, 2005
Messages
6,328
Location
Palo Alto, CA
I have some reservations about this mod (especially now that shiningbeam has a 2-mode Q5 version)...
So how do you ensure electrical conduction (low resistance) between the dremel modded brass pill and flashlight body through the thermal compound?

:thinking:

Note to readers... that 11836 pill appears so bright, because it is attempting to over-drive the LED. I imagine cell resistance and voltage sag helps to prevent the LED from being damaged. But a fully charged RCR123 will feed the LED with 4.2V and current in excess of ~1.4A. thread here...
https://www.candlepowerforums.com/threads/236337
 
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