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Discussion Starter · #1 ·
I was cleaning up my workshop and I started pulling out all my old DIY bike lights. Thought it would be interesting to put together a little history.

1995

I really wish I still had my first DIY bike light or at least pictures. Let's just say it was rather crude. A fog light assembly from the auto parts store, a primitive bar mount, a huge square heavy 7ah sealed lead acid battery that I mounted on a rear rack.

1997



Light head made from plumbing parts, 20 watt GE MR16 halogen bulb, battery belt made from 11 - 1.2v 5ah Nicad D Cells.

This may look like a beast by todays standards, but it was a big step up. You still really noticed the added weight and it really sucked when you fell on the batteries and got a big bruise on your hip. But at least I didn't have to stop every 2 miles and re-strap the big lead acid battery to the bike rack.....

1999



Aluminum light head, 20 watt MR-11 bulb, 11 - 1.2v 4.5ah Nimh 4/3 A Cells

I bought a lathe and mill and started manually machining my housings. That and the switch to much smaller and lighter 4/3A nimh cells was a massive improvement. At this point you can still feel the weight of the light, but not so much that it really changed the way you rode. Run time was about 2 hours and you could carry a second battery for longer rides, but then you really started feeling the weight especially if you were running a bar and helmet and 4 battery packs.

2002







Welch Allyn 10 watt HID bulb and ballast, custom controller mounted to camelback strap, 11 - 1.2v 4.5ah Nimh 4/3 A Cells

When Welch Allyn came out with the 10w HID bulb and ballast I was dying to give the new technology a try. The main motivation was longer runtime and the increased brightness. I was lucky because when they first introduced 10w HID parts, you could buy a developer's kit for $500 dollars that included 4 bulbs and ballast. That worked out really nicely since my wife and 2 daughters had really gotten into riding by this point. We were starting to do 24 hour races as a family so 4 light were just the ticket.

The HID ballast wasn't regulated so the brightness varied a fair amount with battery voltage. The ballast also didn't like being run over voltage and since they were pretty expensive parts I decided to build a custom controller. The controller regulated the voltage so I could run the light right up at peak brightness, provided a battery fuel gauge, low battery shutoff, and included an integrated charger. It connected to the camelback strap so it was really easy to turn the light on and off and see battery status. Since it provides voltage regulation, I was able to update all my HID light to li-ion batteries in 2006 by just getting new battery packs.

I'll have to say these lights served us well. We really put them through a lot over 6 years of use and they've been amazing reliable. I never saw the amount of bulb and ballast failure that seem to be pretty common in the Niterider and L&M HID light that have 3+ years of use. I attribute that to the metal housing which does a much better job of dissipating the heat compared to the commercial lights plastic housings.

There are a couple of things that I didn't like about HID light in general. This may sound very odd to folks on this forum, but I thought they were too bright given the fact that you can't effectively dim an HID light. I really like to run both a bar and a helmet light and I always thought two HID lights was more light than I needed. As a result, I ended up using only a helmet light most of the time.

Mostly because I was just curious to try them out, I've updated 2 of these lights to the new 1000 lumen NGX bulb and ballast. That makes them incredibly bright and they have a really nice beam pattern. But they use even more power, which shortens the runtime for extra lumen I still don't think I really need. The NGX ballast does have a high and low mode, but the low mode is about the same brightness as the original HID.

2008







Combinations of triple and quad XREs and XPGs, bflex driver, 4 cell 18650 li-ion battery

I'll have to say that my HID lights worked so well that it actually slowed my progress toward moving to LED based lights. But, the desire for longer runtimes, less weight, and multiple brightness levels finally created the needed motivation. I also updated my lathe and mill to CNC, which helped with taking the manual labor out of the machining. A friend of mine that is big into model rocketry also got me into DIY anodizing.

I always run a bar and helmet light now and I almost never run these lights on high. Typically I run them at 700ma and I also tend to use broader beam patterns than the HID lights to spread the light over a wider area. I can say without any doubt, this is the by far the best night riding setup I've ever had.

Here are few more pictures that show some of the details of the construction.











And a final picture....the whole collection of machined lights.



2009

So what does this coming year hold.... The only thing that slightly annoys me about my current setup is the weight of the helmet light on really long rides. It's down to about 70 grams with the current light, but a DIYer can never be completely happy.

For my next project, I'm working on a 20mm triple XPG helmet light. To keep the weight down, I'm not going to put the driver in the light head. The plan is to build a custom driver and combine that with the battery pack. The driver will include li-ion protection circuitry, multiple high efficiency buck regulators, remote temperature sensing, a variable brightness mode based on light head temperature. I'm also considering building li-ion charging into the PCB, but the jury is still out on that one. Another idea is to make the battery / driver assembly such that it can clip onto a camelback strap. But I need to do some experimentation to see how well that works.

I'm also going to anodize a lot more of the lights. I have a bunch of nice colors from caswell to try.
 

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Nice battery bandoleer!

I'm beginning to develop lathe envy. All my light work involves square tubing or the occasional pre-fab DX heatsink.

The 2008 series housings are beautiful. A scaled-down version for the 20mm triple XP-G would be awesome.

JZ
 

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Nice collection mm. I started with Cateye & Niterider. They mostly sucked. I was working long hours and only wanted to ride. When the li-ion batterys and the bada$$ leds came upon the scene, I wuz hooked. Your early lights and batteries are soo cool.
 

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Discussion Starter · #11 ·
JimZinVT said:
Nice battery bandoleer!

I'm beginning to develop lathe envy. All my light work involves square tubing or the occasional pre-fab DX heatsink.

The 2008 series housings are beautiful. A scaled-down version for the 20mm triple XP-G would be awesome.

JZ
I have a Sherline Mill and Lathe (http://www.sherline.com/) and I've been extremely happy with them over the years. The quality and accuracy has been top notch and they have tons of very good accessories. I bought them with the CNC stepper motor mounts, but I didn't buy any of the their standard CNC setup. I added the stepper motors, motor drivers and CNC software myself later on. I'm not sure I'd do that again. It's a significant amount of work to build up the CNC setup, but the canned CNC packages are pretty expensive so that would be tough call.

The 20mm housing will be somewhat similar, but should be easier to make since the case won't have to accommodate the driver. I'm also torn over whether to thread the front section of the case like the 2008 35mm housing. It's certainly makes it really easy to change optics without any tools, but the threading operations are a significant amount of the work in machining the cases.
 

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Discussion Starter · #13 ·
cosmoworks said:
Love the latest rev... can't wait to see the 2009 model! Thanks for sharing.
Thanks. I'm thinking I'll post more info on this light as I go if there is interest. In particular, I wonder how much interest there is around the design and creation of the custom electronics. I'm involved a fair amount of open source software with my job. Seems like similar concepts and practices could be applied to LED drivers and firmware. That would give the DIY community ready access to re-useable drivers and firmware that could also be easily customized to meet individual needs if so desired.
 

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I would like to hear more about the external driver setup. I wasn't excited about having to make my light bigger to keep enough room for electrics. I am really looking at external switches and everything. If I did that along with the external driver, I could get my light down to 1.5" deep possibly!
 

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Supernice lights :thumbsup:

Is the switch of the red light waterproof? Is the "pin" sealed with o-rings?
How did you mount the switch on the driver?
How heavy is the red one?

Really really great work !!!
 

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Discussion Starter · #17 ·
rob1111 said:
Supernice lights :thumbsup:

Is the switch of the red light waterproof? Is the "pin" sealed with o-rings?
How did you mount the switch on the driver?
How heavy is the red one?

Really really great work !!!
Yes, there is an o-ring on the switch pin. The switch is the standard switch that comes with the bflex driver. It's not soldered to the bflex board when you get it from taskled in case you want to use a switch mounted off the board. You just have to solder it to the board. In the next batch of these lights, I'm planning to change to different version of the switch with a shorter button height. Right now the aluminum switch pin is hollow so it fits over button. That make the switch alignment pretty sensitive. With the shorter button, the pin will be solid and will just rest on top of the button.

 

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Discussion Starter · #18 ·
I just realized that I should probably elaborate about the switch pin design a little more since it's probably not all obvious from the pictures. This was probably the trickiest part of the design. There are a couple of design points that need to be addressed.

A way to hold the switch pin in the light so it doesn't fall out.

Mechanical limits on the travel of the pin. You don't want the switch itself to be the limit on how far in the button can be pressed. That can cause premature switch failures and also put stress on the solder joint between the switch and the PCB.

Making it waterproof.

It's hard to tell from the pictures, but the switch pin has a groove machined into it. The center section of the light (the internal part that is silver) serves 3 different purposes. It traps the bflex PCB between itself and a narrow ledge in the back of the body to hold it firmly in the light head, the slot in that center section fits into the groove in the switch pin to limit the pin's travel in both directions, and it serves as a heat transfer path between the LED MCPCB and the light body.

Even though the pin is pretty small, it's the second most complicated part to machine in term of the number of CNC sequences.
 

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That is a very nice light and a very nice wright up and just goes to show how things have changed over the years, mostly the battery technology by the look of it.

You are one of the few, (the only other that I know of being Cytoe) to use the bFlex button as George intended and one day I hope do the same but it must be hard to get things aligned and I can't drill a straight hole even with every aid under the sun(really)

I use a manual micro lathe & am too much of an old fart to do anything CNC, in fact it may even take away the part I enjoy the most but your work is very, very nice and 65gr for a Quad is amazing, I can't get under 78gr.

Keep up the good work and thanks for posting.
 

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Discussion Starter · #20 ·
jbflyfshr said:
I would like to hear more about the external driver setup. I wasn't excited about having to make my light bigger to keep enough room for electrics. I am really looking at external switches and everything. If I did that along with the external driver, I could get my light down to 1.5" deep possibly!
I have a working prototype of my driver. It's based on a PIC micro-controller that handles light logic as well as actually implementing the buck regulator control logic. That means I do not have a separate chip for the buck regulator. It's not a general purpose buck regulator since it relies on the fact that the current / voltage don't change very quickly in an battery / LED bike light system. But it works well for LEDs, means less parts for the driver, and it makes control of different current level very easy. Next step is to design a real PCB and have a batch made.
 
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