Comments on: Building Headlights http://alexwetmore.org/archives/570 Thu, 09 Oct 2014 15:41:30 +0000 http://wordpress.org/?v=2.9.2 hourly 1 By: Brandon Ives http://alexwetmore.org/archives/570/comment-page-1#comment-4430 Brandon Ives Tue, 03 Mar 2009 14:28:35 +0000 /blogs/alex_wetmore/archive/2009/03/01/building-headlights.aspx#comment-4430 Back in the early-90s Val and I and a few other folks (Aaron maybe) at Montlake started experimenting on lights. We used PVC tubing for the casing and it worked quite well until stuff got really hot. It was super easy to work with and light. Since LEDs don''t heat as much as halogen lamps PVC would be a good option again, at least for prototyping. I keep thinking about tearing apart either my Nite-Hawk or Blackburn and rebuild it as something I really like. I find the biggest problem is on reflector aspect when trying to optimize the beam. Of course "perfect beam" is really an individual preference and says a lot about the cyclists riding style. Back in the early-90s Val and I and a few other folks (Aaron maybe) at Montlake started experimenting on lights. We used PVC tubing for the casing and it worked quite well until stuff got really hot. It was super easy to work with and light. Since LEDs don”t heat as much as halogen lamps PVC would be a good option again, at least for prototyping.

I keep thinking about tearing apart either my Nite-Hawk or Blackburn and rebuild it as something I really like. I find the biggest problem is on reflector aspect when trying to optimize the beam. Of course “perfect beam” is really an individual preference and says a lot about the cyclists riding style.

]]> By: Steve Chan http://alexwetmore.org/archives/570/comment-page-1#comment-4429 Steve Chan Mon, 02 Mar 2009 07:18:08 +0000 /blogs/alex_wetmore/archive/2009/03/01/building-headlights.aspx#comment-4429 Hi Alex, I was wondering where the headlight project had gone - that housing is very nice! For those who want a simpler standlight design, I was very happy with the standlight that frontranger suggested: http://www.candlepowerforums.com/vb/showpost.php?p=2700461&postcount=52 The final circuit was actually quite simple (http://www.candlepowerforums.com/vb/showpost.php?p=2706860&postcount=70) and while it sounds like you don''t think 2 LED''s are necessary, I found that it was nice to have the extra lighting. Hi Alex,
I was wondering where the headlight project had gone – that housing is very nice! For those who want a simpler standlight design, I was very happy with the standlight that frontranger suggested:
http://www.candlepowerforums.com/vb/showpost.php?p=2700461&postcount=52

The final circuit was actually quite simple (http://www.candlepowerforums.com/vb/showpost.php?p=2706860&postcount=70) and while it sounds like you don”t think 2 LED’’s are necessary, I found that it was nice to have the extra lighting.

]]> By: AlexWetmore http://alexwetmore.org/archives/570/comment-page-1#comment-4428 AlexWetmore Sun, 01 Mar 2009 22:14:35 +0000 /blogs/alex_wetmore/archive/2009/03/01/building-headlights.aspx#comment-4428 Brad -- Thanks for the pointer to the simpler design. I think that would be helpful for people who scared off by me making it too complicated. What do you do to seal the back? That type of plug doesn''t seem like it makes a tight seal. Brad — Thanks for the pointer to the simpler design. I think that would be helpful for people who scared off by me making it too complicated.

What do you do to seal the back? That type of plug doesn”t seem like it makes a tight seal.

]]> By: Brad Riendeau http://alexwetmore.org/archives/570/comment-page-1#comment-4427 Brad Riendeau Sun, 01 Mar 2009 20:35:45 +0000 /blogs/alex_wetmore/archive/2009/03/01/building-headlights.aspx#comment-4427 Take a look at this technique for building a housing. http://www.flickr.com/photos/8040919@N06/page5/ It requires very little machining. 4" provides about the right amount of surface area for the heat sink and by swaging the copper cap into the tube and then using Artic Silver epoxy you get a direct connection for heat transfer. The end can be capped with commercially available caps. The copper cap used is a standard 3/4 inch copper cap. With some grinding on the inside of the aluminum tube they should go together pretty quickly. I cover all my wiring junctures with heat shrink tubing. I use the K2 Luxeon star which is now available with TFFT in a lumen rating comparable to a single Cree CRE at ledsupply.com. They are going for $9.00 The K2 has a higher forward voltage which is closer to the output of the dynamo. My calculations are that the full bridge rectifier and the feed wire provide enough resistance to keep it in the proper usage range. The readily available 20 mm optics fit nicely inside the copper cap with a little silicone on the sides for glue and waterproofing. I popped an 0-ring inside as well for looks as much as anything. Take a look at this technique for building a housing.
http://www.flickr.com/photos/8040919@N06/page5/

It requires very little machining. 4″ provides about the right amount of surface area for the heat sink and by swaging the copper cap into the tube and then using Artic Silver epoxy you get a direct connection for heat transfer. The end can be capped with commercially available caps. The copper cap used is a standard 3/4 inch copper cap. With some grinding on the inside of the aluminum tube they should go together pretty quickly.
I cover all my wiring junctures with heat shrink tubing.

I use the K2 Luxeon star which is now available with TFFT in a lumen rating comparable to a single Cree CRE at ledsupply.com. They are going for $9.00

The K2 has a higher forward voltage which is closer to the output of the dynamo. My calculations are that the full bridge rectifier and the feed wire provide enough resistance to keep it in the proper usage range.

The readily available 20 mm optics fit nicely inside the copper cap with a little silicone on the sides for glue and waterproofing.

I popped an 0-ring inside as well for looks as much as anything.

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