Basic modding questions

Flashlight Modding and DIY Parts
1

Hi,

my Romisen RC-G2 has grown a little unimpressive with its old XR-E P2 emitter, so I would like to do my first emitter swap on this one. I just ordered one of the new XT-E R5s from Kaidomain, so I probably have a few weeks left to learn some basics

Anyway, I am pretty experienced at soldering, but what I usually solder are pcb boards and such. The idea of soldering on top of a piece of metal that is designed to work as a heatsink seems to me like trying to eat soup with a fork. Are there any special techniques you could share with me?

I've got a 60W digital regulated soldering iron. Usually I set it to 310 °C for electronics and 340 °C for bigger parts like jacks and plugs. What temperatures do you solder at?

And, should I use thermal adhesive between the pill and the emitter board or is the non-sticky thermal compund enough? Maybe a mixture of both?

Thanks for enlightening me!

2

I set my iron to 350c and use Fujik thermal adhesive to stick the emitter to the pill. You need to work fast, if the board get's to hot the emitter will dedome or fall completely off and you are in trouble.

http://www.dealextreme.com/p/fujik-silicone-thermal-glue-50ml-grease-like-4579

3

Thanks for your input.
Concerning the Fujik thermal adhesive, there is a cheap offer for 20g on ebay:
http://www.ebay.com/itm/260612077588

Do you think it is the same stuff? The seller doesn't state that it is an adhesive, but then again, DX doesn't either.

4

It's hard to tell if it's the same, but the 90 gram tube DX sells is enough to do about 100 emitter swaps.

5

While we are at the topic.. any good tips on centering emitters?

6

I just measure the space around the star and the side of the pill if the emitter is centered on the heatsink

The fujik grease in the little white tubs isn't what E1320 is using like what Dx sells much better ..I thought at one point someone was selling that on ebay .. but who knows .. ebay is just a crap shoot

7

Fujik really is crappy stuff, I tried it on a P7 mod ages ago, the led tuned blue, redid it with Arctic Alumina the thing is still going strong som years later.

8

I have made over 100 drop ins with Fujik from DX in the tube not to mention all the modded lights I have used it on and I haven't had a problem with it. I even used it to stick the shift knob back on my Jeep, I think it's great stuff.

9

I've got some Arctic Silver used for heat sinks with CPUs I could use up, will that work?

10

Soldering the leads onto the star is easy. The LED stars have preformed soldering pads. Even my weak battery-operated 6 watt soldering iron is sufficient.

For attaching stars to heatsinks I usually use a dab of Arctic Silver thermal epoxy right in the center of the star and then surround that with thermal compound.

11

That's clever. Using only thermal epoxy would probably be a rather "terminal" solution...

12

It will work better than the other compounds discussed in this thread.

13

Yup. Works very well. Keeps the star firmly in place as if I'd epoxied the whole thing and provides good thermal transfer. But at the same time I can still remove the star by sticking needle nose pliers into the lead slots and twisting to break the bit of epoxy in the center.