Tinkering a C-8

Hello CPF

I have here a C-8 3w cree (P4) flashlight from DX (sku.6131), that served me for about half a year now. I only had problems with flickering during one summer night when i used it for a long walk- And now that i got into flashlights a bit more, i figure i can make it better than new. So let me tell you my ideas and you tell me if they are any good. :duh2:

The problem is in the pill, and i want to make a few adjustments to it.

1: it isn't screwed in tight enough, and i think it therefore probably doesnt transfer heat to the body as well as it should. I tryed wrapping aluminum foil around the pill, but as it screws in it doesnt really stay on the pill... Maybe i could stuff some foil in the inside of the tube and then try to screw the pill back in... Or just apply a shitload of thermal paste on the thread... Easyest way to solve this one?

2: The emitter star isnt attached to the pill. Is that a problem? The reflector does push it down to the sink when you put on the bezel, so this might not be a problem.. I dont have any suitable glue, and i'm afraid that putting screws in would stick too far out for the reflector, that leaves me with trying to solder the star to the aluminum part... Is this a good idea, or is it better to just leave it so its held in place by the reflector? It could be dangerous tho when using it without the reflector as a pure flooder...

3: Any harm in soldering the outer ring of the driver to the pill? Right now it only makes contact if the bezzel is pushing everything together... But if i made a contact with the heatsink, i think i shouldn't have any more problems... Any harm in that maybe?

Here are some pictures in case my english sucks that bad. :mecry:



Thanks for any given advice

Anyone?


I did figure out I won't solder the star to the sink just yet, because i might replace it with a better emitter. I'll just try harder to find appropriate low profile screws to attach it.

T0RN4D0 said:

Hello CPF

I have here a C-8 3w cree (P4) flashlight from DX (sku.6131), that served me for about half a year now. I only had problems with flickering during one summer night when i used it for a long walk- And now that i got into flashlights a bit more, i figure i can make it better than new. So let me tell you my ideas and you tell me if they are any good. :duh2:

The problem is in the pill, and i want to make a few adjustments to it.

1: it isn't screwed in tight enough, and i think it therefore probably doesnt transfer heat to the body as well as it should. I tryed wrapping aluminum foil around the pill, but as it screws in it doesnt really stay on the pill... Maybe i could stuff some foil in the inside of the tube and then try to screw the pill back in... Or just apply a shitload of thermal paste on the thread... Easyest way to solve this one?

Click to expand...

Thermal paste sounds easiest. Copper tape would be another idea, but no Idea how well that would work.

2: The emitter star isnt attached to the pill. Is that a problem? The reflector does push it down to the sink when you put on the bezel, so this might not be a problem.. I dont have any suitable glue, and i'm afraid that putting screws in would stick too far out for the reflector, that leaves me with trying to solder the star to the aluminum part... Is this a good idea, or is it better to just leave it so its held in place by the reflector? It could be dangerous tho when using it without the reflector as a pure flooder...

Click to expand...

The emitter doesn't need to be attached to the pill. The contact is mainly for heat transfer. Thermal paste is the standard solution here. Soldering will lead to worse heat transfer if you don't have something like a reflow oven. Screws shouldn't be necessary either - as there is no electrical contact except for the wires, it won't make things better.

3: Any harm in soldering the outer ring of the driver to the pill? Right now it only makes contact if the bezzel is pushing everything together... But if i made a contact with the heatsink, i think i shouldn't have any more problems... Any harm in that maybe?

Click to expand...

As said, I don't think it's necessary.

I know its just for thermal conductivity, but if i remove the reflector or bezel to use it as a candle, i'm letf with 0 thermal conductivity between the star and the pill

And not that thats a problem because the flashlight doesn't work because of the bad ground contact anyways...

Ah i'll play with it today when i get my soldering iron back from my neighbour.

Many thermal pastes act a bit like glue - they hold the pcb in place more or less.

I would test it with thermal paste alone first before trying screws - and you should be careful not to screw the screw in to far, or else if you hit the driver

I just put a bit of solder on the underside, and i squished about 3g of the silver paste on the threads and bolted the sucker back in. And i'll keep a look out for really short n small screws with small heads