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Hi all,

Been lurking here for a while and have been very impressed by the quality of work on here.

Am looking to build a light for use on unlit roads. Some quite steep and twisty downhills on the route I do, so useful to have some good lights... I also just fancied building something...

So here is my kit of parts I'm planning to order - would be great if someone could say I'm going the right way here. As you can see, I'm trying to do this relatively low cost.

LEDs - 3x XR-E R2 from DX - $18.54
Driver - 15W boost 5-mode from DX - $3.99
Battery/charger - 7.2v x 3800mAh x 2 plus charger from ebay - about $30
Optics - 3 x Carclo 8 deg spot - about $5
Housing - aluminium lidded enclosure - about $4

Total cost - around $61 and then a few bits and pieces (wire, connectors, switch, arctic alumina etc.)

Couple of questions:
1) Are these optics a good choice - my alternative is to get L2s which I can also get from Farnell
2) I was planning on mounting the stars to a piece of 1.5mm thick aluminium angle, and then sticking that into the case (using AA both times). Will this be sufficient to transmit heat to the case, and will the case need additional heat sinking?
3) The boost driver seems to have a large coil on the top - should I use arctic alumina to bond that coil to the case to pull heat out of it (and stop the driver rattling around)?
4) I was going to cut a window into the side of the housing for the lights to shine out. I was going to cover the window with a bit of perspex - is 2mm thick sufficient? And to stick this inside the case do I use epoxy or something else?
5) I can't seem to find a "push to break" momentary switch. Presumably a DPST momentary switch would also work?

Thanks for taking the time to read this, and even more if you can provide any thoughts on making my first build a successful one!

Cheers!
 

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Just a quick reply here
2) There are some smarter looking Hammond cases out there too. If you can find slightly thicker angle plate I'd use that. But I'm sure someone more experienced in using plate will give some info there!
3) Yip, id attach the driver to the housing, mainly to stop it rattling around and causing a wire to come loose. I dont know the thermal needs of that driver.
5) Search for Apem switches at Farnell. They have loads of SPST mom switches that will work perfectly.

Good luck!
 

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Driver - 15W boost 5-mode from DX - $3.99
Let me know how this driver works out for you. I bought this driver to play with, but haven't hooked it up to anything yet. It looks VERY robust.

Battery/charger - 7.2v x 3800mAh x 2 plus charger from ebay - about $30
If I were to start a new project today, I go would go with Li-ion. It has more energy per weight AND volume, and is not nearly affected by cold as NiMH.

Optics - 3 x Carclo 8 deg spot
My preference is for a mix of narrow and wide optics, with the narrow optics used on the helmet and the wide optics (or mix of wide and narrow) on the handlebars. The wide optics are very important for illuminating your peripheral vision, which is important if you're riding single track through trees, ducking overhead tree branches, etc. For purely road riding, it might not be so important. Experiment with different optics and see what works best for you.

I can't seem to find a "push to break" momentary switch.
These waterproof switches seem popular among the DIY light's I've seen. I believe Judco makes them:
http://www.batteryspace.com/component-switchin-linelightswitchpush-button.aspx
 
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