# Nostalgia



## MtbMacgyver (Jan 23, 2007)

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.


----------



## lidarman (Jan 12, 2004)

Wow, That is light passion!


----------



## deesta (Sep 7, 2008)

Wow, great looking collection :thumbsup:


----------



## troutie-mtb (Sep 20, 2007)

Excelent MM real good to see you have kept your history 
sadly most of mine is in photos only as old projects get recycled .

Impressive display of progress over the years .

The old waist belt with the batteries in looks awesome .


----------



## Jim Z in VT (Sep 9, 2007)

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


----------



## lsocoee (Oct 29, 2009)

That's a nice collection, but I'm a bit disapointed to not see a small oil lamp with reflector.


----------



## Funrover (Oct 4, 2006)

Wow, come a long way. 11 D batteries.. WHOA!


----------



## OldMTBfreak (Apr 8, 2006)

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.


----------



## Jim Z in VT (Sep 9, 2007)

lsocoee said:


> disapointed to not see a small oil lamp with reflector.


Carbide miners lamps blow away those old school oil lamps :lol:

JZ


----------



## cosmoworks (Jan 22, 2008)

Love the latest rev... can't wait to see the 2009 model! Thanks for sharing.


----------



## MtbMacgyver (Jan 23, 2007)

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.
> 
> ...


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.


----------



## MtbMacgyver (Jan 23, 2007)

Thanks for all the kind words. The sheer quantity of really cool lights posted on here is amazing. Seems like there must be some connection between between mountain biking and folks that like doing this sort of hobby.


----------



## MtbMacgyver (Jan 23, 2007)

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.


----------



## jbflyfshr (Jul 24, 2006)

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!


----------



## Billabang (Sep 2, 2007)

Dude, I really love that red lamp w/ the bFlex mounted verticaly.... It's giving me ideas....


----------



## rob1111 (Jun 16, 2009)

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 !!!


----------



## MtbMacgyver (Jan 23, 2007)

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?
> ...


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.


----------



## MtbMacgyver (Jan 23, 2007)

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.


----------



## yetibetty (Dec 24, 2007)

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.


----------



## MtbMacgyver (Jan 23, 2007)

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.


----------



## El34 (Jan 11, 2009)

Cool looking lights Mac
I see you use the Marwi mounts also.

Takes a lot of time/labor to make that stuff from scratch


----------



## Vancbiker (May 25, 2005)

yetibetty said:


> You are one of the few, (the only other that I know of being Cytoe) to use the bFlex button as George intended


My single MC-E light uses a bFlex and the original switch. I did mine a bit different. I soldered the switch on the "backside" of the board. This require a little bending and trimming of the metal tabs on the switch to clear the surface mount components. I did that so that the micro-controller could be mounted in contact with the LED mount. I did this to allow the thermal sensing capability of the bFlex to be as sensitive as possible to the LED temperature. The switch is just under a counterbored section of the housing and covered with a 1mm thick rubber pad glued to the housing.


----------



## jbflyfshr (Jul 24, 2006)

*In that case*



MtbMacgyver said:


> Next step is to design a real PCB and have a batch made.


Let me know if you need a third party tester  and I will fast forward my light building just to test it...

Just saying


----------



## MtbMacgyver (Jan 23, 2007)

yetibetty said:


> 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.


Thanks, for the complements on the lights. I have to say I'm really enjoying them. The weather was so nice in the NC mountains this weekend that a group of riding buddies and I took advantage of the long runtime and rode well into the night this weekend.

Before I did the conversion to CNC, I was worried about the same thing, would CNC take away the enjoyment I get from manual machining. I guess it depends on your approach, but I've been pleasantly surprised that CNC has actually increased the enjoyment I get from machining. I work at a fairly low level with the CNC in setting up tool paths and machine operations and I've found that's the part I enjoy about machining. The CNC just automates most of the drudgery aspects. And I still do a lot of completely manual machining for stuff I'm only going to do once.


----------



## MtbMacgyver (Jan 23, 2007)

El34 said:


> I see you use the Marwi mounts also.


Yes, I was introduced to them back when performance re-marketed Marwi lights as the Performance Viewpoint Lights. When they dropped them they unloaded a lot of the accessories for cheap. I really like the fact that the same bracket work well with both the helmet and bar mount.


----------



## El34 (Jan 11, 2009)

Where did you ride in NC??
I am in Pisgah Forest, I am sure you know that place.

I have a CNC machine also.
I built it from scratch.
see the CNC aluminum machine links on this page.
http://www.el34world.com/Misc/Cnc/CNC0.htm

Huge learning curve, but what a cool machine.
http://www.el34world.com/Misc/Cnc/CNC0.htm


----------



## jbflyfshr (Jul 24, 2006)

EI34

Way above my abilities. Nicely done.


----------



## El34 (Jan 11, 2009)

Thanks, appreciate it
Could not have done it without the huge CNC community and DIY parts that are available
Home CNC'ing has exploded in the last several years


----------



## tobymack (Nov 12, 2008)

MtbMacgyver,

I'm very interested in your PIC LED controller - if you feel like sharing the design that would be great!

I've done an external driver design (shown here....) using a PIC to control it but cheated by using a kennan driver. longer term I want to replace the kennan with my own converter but hadn't decided whether to use a PIC to control it or something like a 1360 LED driver. 
I was a bit worried that using a PIC I'd spend a lot of time trying to make the control loop stable. Did you have any problems with this?

Toby


----------



## MtbMacgyver (Jan 23, 2007)

El34 said:


> Where did you ride in NC??
> I am in Pisgah Forest, I am sure you know that place.
> 
> I have a CNC machine also.
> ...


You'll certainly recognize the trails we rode. We didn't get up there until late afternoon on Saturday so we rode the following into the night on Saturday night.

Claw Hammer=> Black Mountain=> Buckwheat=> Bennet Gap=> Claw Hammer=> Black Mountain=> Thrift Cove=> Grassy Rd=> Sycamore Cove

I had looked at your CNC pages earlier. An impressive setup! Where did you get the ball lead screw?


----------



## MtbMacgyver (Jan 23, 2007)

tobymack said:


> MtbMacgyver,
> 
> I'm very interested in your PIC LED controller - if you feel like sharing the design that would be great!
> 
> ...


No, I didn't have any problems with the control loop. This is where it really helps that in a bike light system the voltage / current characteristics of everything involved changes relatively slowly. You don't really need a very fast response time from the control circuit like you do with a general purpose buck regulator. That makes it really easy to keep the control loop stable.

The key factors that have an influence on the current flowing through the regulator and LED are Vf, which changes with temp and also from LED to LED, battery voltage, user input to change to the brightness levels, battery connect / disconnect, LED connect / disconnect. All things that happen on slow time scale.

Battery and LED connect are the only ones that are a little tricky to handle. You have to make sure when there isn't current flowing through the converter that it doesn't sit in a state with the pass FET on 100% of the duty cycle. If that were the case, the current could ramp up so fast that it could potentially damage the LED before the control loop responds. That's pretty easy to handle in the MCU firmware as a special case. The control logic has a specific state machine to handle the transition from a zero current state to a current flowing state. While in zero current state, the pass FET duty cycle is locked at a very low duty cycle.


----------



## tobymack (Nov 12, 2008)

Thanks, that sounds good. Perhaps I need to experiment a bit. 
Out of interest, which PIC are you using? I was thinking of using a 12F683 (as I already have some) but have yet to check if it has the features/pins I need.

Toby


----------



## El34 (Jan 11, 2009)

> Claw Hammer=> Black Mountain=> Buckwheat=> Bennet Gap=> Claw Hammer=> Black Mountain=> Thrift Cove=> Grassy Rd=> Sycamore Cove
> 
> I had looked at your CNC pages earlier. An impressive setup! Where did you get the ball lead screw?


Yeah man, great trails
Thrift is one long ripping downhill, eh? Fast and fun.
We do several of those as night ride combos also.

I got the ball screww off Ebay. Don't remember who, but it was a Canadian company selling them. Huge difference having all ball bearings on the X-Y and Z. 
My first machine was made of Oak and used oilites, but it was a great leaning tool.

see ya


----------



## MtbMacgyver (Jan 23, 2007)

tobymack said:


> Thanks, that sounds good. Perhaps I need to experiment a bit.
> Out of interest, which PIC are you using? I was thinking of using a 12F683 (as I already have some) but have yet to check if it has the features/pins I need.
> 
> Toby


My prototype uses a 16F876 just because it was convenient. But it's a bigger chip than I need/want on the final board. The final board will most likely be based on the 16F884. I've used the 12F683 before in past projects. It won't work for this project because it doesn't have the PWM module needed to implement the buck converter.


----------



## tobymack (Nov 12, 2008)

according to my datasheet the 12F683 does have a PWM module although I have never actually used it. 
In fact the description looks almost identical to that of the PWM in the 16F884.:thumbsup: 
(except it is only single channel)

I'm not sure if it has the resolution or frequencies I would need but if the F884 works then I guess it should. I suppose my next step is to look at it properly and have a bit of an experiment.
Out of interest, do you mind saying what inductor and pwm frequency you are using?

Mind you, at current rate of progress I will probably get to this in about a years time  perhaps I should get off the computer and finish the light I am currently working on!

Toby


----------



## MtbMacgyver (Jan 23, 2007)

tobymack said:


> according to my datasheet the 12F683 does have a PWM module although I have never actually used it.
> In fact the description looks almost identical to that of the PWM in the 16F884.:thumbsup:
> (except it is only single channel)
> 
> ...


You're right, I misread the info in the device selection tables. The 12F683 does have a PWM module.

So far I've been playing with frequencies of 78 and 156khz and 54 and 112 uh inductors. All combinations have actually worked well. I'll make the final selection based on the amount of ripple I think is acceptable in the current to the LED. It appears in practice there can be a lot of ripple in the current to the LED and it's not noticeable to the human eye, so I don't think that'll be the deciding factor. I think optimizing LED and converter efficiency will likely drive the final selection of frequency and inductor.


----------



## tobymack (Nov 12, 2008)

Thanks, it will make it easier knowing I can start from there. 

Toby


----------

