MC-E Dynamo Light

[StevelKnievel]

I haven't had much time for light building recently, but I finally bought a dynamo hub (Shimano DH-3D71) and I had some J bin warm white MC-Es sitting around so I had to build something. I've already built a number of dyno lights with the 4-up XR-E boards from Cutter and everyone who's using them loves them so I figured the MC-E would work well too. The MC-E is wired 2s2p and uses a bank of supercaps to provide a standlight.

I use it for mountain biking in conjunction with another warm white MC-E on my helmet. I am sold on the benefits of warmer tints in the wilderness! My other night riding setup is a 1500+ lumen handlebar light and 600+ lumen helmet light, both with cold white Crees. With this setup I have a 400 (or less) lumen bar light and a ~500 lumen helmet light and I actually feel like I'm riding faster because of the improved color rendering and reduced glare. (Don't get me wrong...I still appreciate raw output! 1500 lumens of warm white is on the way as soon as I have time!!!) I do think the benefit of warmer tints mostly depends on the terrain. It seems there is almost nothing to gain with warm white on the road, but down here in the swamps the greens and browns come alive and the glare coming off the mud, wet leaves and such is greatly reduced.

Anyways, enough rambling. Here are some pictures of the light and a link to a crappy too-dark video I made riding around the 'hood.

Spinning the wheel with my hand, trees are 65-70 ft away:

Updated beamshots with cool and neutral emitters!
Cool white, MTBR recommended camera settings, Treeline ~100ft:

Neutral white, MTBR recommended camera settings, Treeline ~100ft:

Video:
http://www.youtube.com/watch?v=NElJN5HvR54

 

[sping]

So how come not 4S on the light? Wouldn't you get a lot more output with 4S? Does 2S2P make the light come on better at slow speed?

If so, would Martin's deluxe auto-switching circuit 12 give the best of both worlds?

 

[[email protected]]

Looks like a pretty nice light. The pictures and video make it look like it has a strong center spot with a fairly wide sidespill. Do you get any artifacts in the central spot from the 4 dies in the MC-E? When playing around with the P7 earlier this year I found I'd get a plus sign pattern in the center of the spot if I had the focus off a bit.

With regards to the video ... if you actually stopped at the stop signs we'd have had a few more examples of the standlight function

Mark

 

[StevelKnievel]

4s with the fullwave circuit would have a higher output but doesn't come online at a low enough speed for mountain bike use 4s voltage doubler comes on fast and has a less peaky output... either way with 4s I'd have to use 3 supercaps (which I didn't have room for). The circuit had to be contained within the light housing, so the autoswitcher is out, it's far to large.

No artifacts thanks to the sputtered reflector, otherwise yes the MC-E has similar optical properties to the P7. Stopping at stop signs isn't exactly my forte, they don't call me StevelKnievel for nothing :naughty:. (Actually I was more concerned with not dropping my camera than obeying traffic regs.)

 

[TSWrench]

Very cool light, Stevel! Sent PM.

 

[syc]

Nice light - now I see why your housings are always so nice, you have a lathe!

use a fullwave rectifier circuit and wire the MC-E 2s2p... the forward voltage gets cut in half so 2 supercaps will work.

The circuit you are using is pretty much a double-strength version of what I'm hoping to build, so I'm really happy to see how well such a simple circuit works.

 

[ionicbreezer]

Liking the outcome of your dynamo-driven single MC-E light, I too have built one! :twothumbs The MCE LED is on a star board wired in series that I got from ledsupply.com. I used circuit 8 found on pilom.com for a 4 LED in series circuit. I did exactly as specified from that website except C1 was replaced with three 1.5F 5.5V supercaps in series. As for lens, I used the the L2 Cree spot optic module (http://www.ledsupply.com/l2-optx-1-006.php). I haven't really gone out for a ride yet. My first impression is that the optic projects a light beam that is much wider than the claimed 6 degrees. No obvious artifacts in the beam pattern was observed. I am quite happy with the build. The light came on from just walking the bike!

 

[FrontRanger]

My first impression is that the optic projects a light beam that is much wider than the claimed 6 degrees. No obvious artifacts in the beam pattern was observed. I am quite happy with the build. The light came on from just walking the bike!

:welcome: Are you using any of the clip-ons advertised on that page you linked? Please do post beamshots when you have a chance. I think a lot of us here on the Bicycle sub-forum are working on ore contemplating MC-E lights. Optics is the hardest part to get right, so the more beamshots here, the merrier! Thanks.

 

[FrontRanger]

Looks compact and clean, SK. :twothumbs How is it working out thermally? I know it depends much on ambient and airflow. Just trying to get a basic idea of how much heatsink area is needed for a MC-E. Thanks.

 

[herulach]

Completly OT I know, but do those Shimano DynoHubs hold up well enough for 'proper' mountain biking? I'm thinking as much about getting dragged through axle deep mud and sideways rain thats unfortunately so common on this side of the pond.

 

[StevelKnievel]

ionicbreezer- Awesome! Let us know how that optic ends up working. It's been a challenge to get a good beam with the MC-E.

FrontRanger- The cool thing about dynamo lights is that they only generate heat when you're moving, so there's enough airflow to keep it cool without excessive finning on the housing. My dynamo setup is only running the MC-E at about 3 watts, so the heat is minimal anyway.

herulach- My hub's holding up well so far, it still feels great and our rides venture through lots water, sand and mud. One of the other riders in our group has been using his for almost a year with no issues. Ktronik is a regular CPF'er who's been using a Shimano dyno hub for mountain biking for quite a while, as far as I know he hasn't had a problem either.

 

[ionicbreezer]

>Are you using any of the clip-ons advertised on that page you linked?

I am not using any of the clip-ons, but I do have a 2mm thick Lexan in front of the lens.

>Please do post beamshots when you have a chance.

It is kind of hard to get a beamshot of the dynamo powered light, but I will try something later this week and post some pics. I am switching between the L2 optics and the Cree 8 degree optic for the XR-E (http://www.ledsupply.com/247-10-lens.php). The cree optic appears to give an even and tighter beam than the L2.

On my commute home tonight with the L2 lens, I have no complaints :twothumbs. It lit up the whole road like an automobile light, but doesn't project as far as I would have liked. It is definitely brighter than the Dinotte 200L and on par with 2x200L. I will ride with the Cree 8 degree tomorrow and see how it is...

 

[ionicbreezer]

Here is my rendition of a dynamo-powered MC-E headlight with some photos. The beamshots were taken with the following camera setting: 0.6sec exposure, 800iso, 5.6f. The light was placed directly on top of the camera, which was about 2.5feet off the ground on a tripod. The center of the beam was aimed toward the tree in the middle of each photo. As a reference, I also took a photo of the battery powered Dinotte 200L. The lens currently on the MC-E headlight is a Cree star optic designed for the XR-E. The MC-E light was hand spun while mounted on a truing stand at the time the photo was taken. Enjoy! :thumbsup: The MC-E LED I got was a K bin LED. As you can see from the photos, the temperature of the light is definitely warmer than that of the 200L and the beam is not as focused. Although it is definitely adequate for my use (commuting on rural roads), I wish the beam is more focused and project further out like the 200L

Light assembly:

Dinotte 200L:

Dynamo-powered MC-E Photo 1 (Cree Star Optic for XR-E):

Dynamo-powered MC-E photo #2 (Cree Star Optic for XR-E):

OK... more photos. This time with the L2 optic:

Dinotte 200L Reference:

MCE with the L2 optic modified with aluminum foil wrapped around the side to minimize side scattering:

With the aluminum foil mod on the L2 optics, I was able to achieve a more focused beam very close to that of the 200L!

 

[FrontRanger]

Here is my rendition of a dynamo-powered MC-E headlight with some photos....

Thanks for taking the time with truing stand, ionicbreezer. It's really nice to see a direct comparison of the optics.
:thanks:

 

[ionicbreezer]

Thanks for taking the time with truing stand, ionicbreezer. It's really nice to see a direct comparison of the optics.
:thanks:

You are welcome! I slapped on the oval sub-lens on the L2 optic today, and I must say the beam pattern is perfect! It projects a nice even, narrow, cone-shaped beam onto the road with minimal side spillage. The candles are right where I needed them. No hot spots.

 

[mrbubbles]

Interesting circuit, can you provide some info?