First build help.

[davidwhittingham]

Hi guys, I'm a long time reader but first time poster.

This is my first real light that I am making so I want it to work, if you guys spot a mistake please tell me. Also is there anything I have not considered?

I want to make a housing out of aluminium rod to a cylindrical housing with 4 leds and a red warning led. I will make the housing on the lathe with a 35 mm outside diameter and a 30mm inside diameter, there will be cooling fins to increase surface area 2 mm deep every 2 mm. The switch will be on the top and the led and power connector will be located on the back. I would also like it if the light had a low mode and a flash mode.

I think I will use:

1x Home made casing
4x cree xpg r5 LEDs
1x Task led max flex driver
1x Push to make switch
1x 5mm indicator LED

I am a little unsure about the following:

Battery packs? There are so many. I want a lightweight 7.2 volt pack, but there are so many to chose from. What would you suggest. I wont be out for longer than an hour and a half.

Connectors. What do you guys use, and does it need to be waterproof.

Optics, is there any optics which will allow 4 leds in a circular patter?

Also I see the option of having a light engine when ordering leds from cutter. Is this necessary?

Lastly do the leds come on the stars, and if not how do I get them with stars?

Thanks for reading,
David :thanks:lovecpf

 

[marcopolo]

AT 35mmOD 30MM ID your wall is only 2.5mm (not a problem in itself) but when you take into account you want 2mm deep fins that only leaves a wall at the base of the fin only 0.5mm thick. It's too thin for aluminium. Go to at least 1mm so presuming your OD is fixed at 35mm make your ID 28-29mm.

If you are buying from Cutter electronics (sensible option) get a pre-made MCPCB with LED's such as the XPG254S which is 25mm dia, has 4 LED's pre-soldered (this is called a light engine) and a matching 25mm 4 way round optic ie the PL1151 (25mm) or PL1152 (35mm maybe better for you) - all listed on the cutter website. Do not buy a star board or round with single LED's unless you plan a custom shape CNC case.

Battery - I always use Li-po. However be prepared for fires/explosions and imminent death and your house burning down. Well thats what the 18650 fanboys always say. Otherwise go 18650. It really is personal taste. How much run time do you need on full/half/quarter power?

Use a standard 2.5mm DC jack and socket recessed into case. Puts up with rain but I wouldn't submerge it.

Marco.

 

[davidwhittingham]

Thanks marco

What angle do you guys use on a xpg optic

David

 

[marcopolo]

As tight as possilbe. These optics throw wider and much more diffused than reflectors. The 10deg optic will give you usable light out to 30deg! Avoid the 25/45deg optics unless for some specific reason; say you only ride on twisty forrest trail.

One thing to bear in mind if you havn't heard. THE XP-G has a bigger die size than the XP-E so although the optics are interchangeable you will always get a wider angle with th XP-G on the same optic. It's compensated somewhat by the fact the the XP-G throws out more lumens.

 

[Tidra]

Do yourself a favor and buy DX bike light, spare time and money,...

 

[TorchBoy]

Related question - do the 10 mm optics fit on the 10 mm round boards, or just on the 10 mm square boards?

 

[hp84117]

Related question - do the 10 mm optics fit on the 10 mm round boards, or just on the 10 mm square boards?

The square optics have a leg on each corner, with two of the legs (opposite sides) having a very small pin to fit into very small holes on the square board. The round boards don't fit the leg pattern on the optics and would require another way to align and support them.

 

[TorchBoy]

Thanks very much.