Cutting led base?

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Matjazz
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Cutting led base?

I'm working on a headlamp project and I'm wandering if its safe to cut the base board of led or would that short the contacts? I need it to be smaller than 16mm.

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wiljen
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You can find some on 14mm bases to start with.  That is easier than cutting the larger ones.

 

http://www.dealextreme.com/p/cree-q5-wc-led-emitter-with-14mm-base-11023

Crux
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Yes, you can cut them down to size.  Just do it carefully and inspect the cut edge when done.  There may be some metal burrs smeared over the cut edge.  Look closely, if the copper foil touches the aluminum it may cause problems.

How do you plan to cut it down?  Grinder?  File?  Metal shears?

keltex78
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Cutting the bases is difficult but can be done. I did 3 of these to make the emitters I had fit into a light I was modding and it was very frustrating. I would second the recommendation of using an LED on a smaller base, or mounting the emitter you have on one yourself...


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It sounds like the XM LEDs won’t really be suitable for flashlight use. Pity…

Confusius
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Either you file it down carefully... or if you are lazy like me you use a large diagonal cutter and nibble away what you don't like. Careful inspection of the corners is a must. Use a fine file to deburr the edges, take special care on the conductive layers. You may need to remove some more isolating material from the conducting pathways to make connection to the LED. It's a bit messy, but quick.

Good luck!

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okwchin
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I find myself having to trim some boards every now and again. I use a bench grinder and carefully take away the edges a little at a time, being careful not to let it slip out of my hands. If your cutting alot of the board away, you will likely be cutting into the copper wire traces, and removin the solder pads, so all you haea to as everyone before me has said lol, is just ensure you move to a fine file and clean up the edge to ensure there are no metal shards and fragments that connect the copper wire trace to the base. Other than this you should be able to scratch away the silkscreen layer off the top and solder to the copper tracks as per normal.

"like everyone else - I’m looking for my next “last” flashlight" -  ohnonothimagain

Matjazz
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I looked for a XML on 14mm and found one at focalprice. Hopefully I won't need to cut it.

Thanks for sharing your experience:

Now I see

heinzeins
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I just received the wannabe 14mm XM-L from Focalprice but turns out it has a 16mm base. Lets see how they handle the RMA...

willie
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okwchin wrote:
I find myself having to trim some boards every now and again. I use a bench grinder and carefully take away the edges a little at a time, being careful not to let it slip out of my hands. If your cutting alot of the board away, you will likely be cutting into the copper wire traces, and removin the solder pads, so all you haea to as everyone before me has said lol, is just ensure you move to a fine file and clean up the edge to ensure there are no metal shards and fragments that connect the copper wire trace to the base. Other than this you should be able to scratch away the silkscreen layer off the top and solder to the copper tracks as per normal.

Hate to play MrSafety but aluminium or copper sould NEVER be ground on a bench grinder. Alumimum or copper should never make contact with a stone or diamond wheel. The proper method is to use a belt sander for non-ferrous metals.

df2dot
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why B/C it clogs up the stone ??

willie
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Aluminium and copper will embed in the wheel. In worst case scenario loading of the wheel will cause excessive heat and stone fracture/failure at high RPMs, leading to possible loss of life or limb.

willie
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Wood, plastic, zinc and brass are other materials on the do not list.
Chicago X
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I have had decent luck with some heavy-duty hole punches.

Take a good look at the traces embedded in the PCB before you cut by shining a torch behind it. 

Final shaping/lapping is done by hand with some wed/dry sandpaper.

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Boaz
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Matjazz wrote:

I looked for a XML on 14mm and found one at focalprice. Hopefully I won't need to cut it.

Thanks for sharing your experience:

Ah Focal price that will be fun .. get a gun and just shoot yourself now and save yourself all the anguish of dealing with these guys ...

καὶ τὸ φῶς ἐν τῇ σκοτίᾳ φαίνει καὶ ἡ σκοτία αὐτὸ οὐ κατέλαβεν