znomit
Enlightened
English:
http://lerch.no-ip.com/atm/Silver.htm
I did some glass rods 10 years ago. Think it took 3-4 goes to get right. The beakers we used still have a nice coating.
Let's design a road front light beam
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English:
http://lerch.no-ip.com/atm/Silver.htm
I did some glass rods 10 years ago. Think it took 3-4 goes to get right. The beakers we used still have a nice coating.
The solutions already exist, in the form of German StVZO complied lights (BUMM, Schmidt, etc), just not at a cost that most are willing to pay, or at a brightness level that you may be used to/want (eg many are dynamo powered, so limited to maybe 3W).
Stuffing a P7, MC-E etc into a BUMM Ixon IQ Speed would be interesting, if it didn't melt... Pattern would be a bit compromised though. Compact optics designs are not physically possible with large emitter.
Lend me some dollars and I'll road test a Big Bang for you...
PS just installed twin Magicshine MJ-808s, awesome! ...apart from the beam pattern. Contemplating if I can mod them into a projector unit.
I just discovered how cool the BUMM stuff is. I will check for shootouts between the edelux, ixon iq speed, ixon speed
The Busch&Muller IQ-TEC mirror (that this thread has been discussing) seems to be an easy answer. Most of those BUMM lights seem to use it.
The form factor is perfect as well...emitter and heatsink sitting on top of the leading edge puts the fins directly in the path of the wind. A glass shield can be mounted directly to the heatsink. The resulting warm glass would solve the condensation and snow issue that LEDs face.
As far as modding goes, I believe the edelux comes with a nice copper heatsink.
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the reflector of the cyo r is very good, because it enlightens the nearfield.
the modding by placing better bins of the xp-g into it may not bring the wow-effect, but its more and makes fun. my plan is to drive two cyo-r on my new coming bike, so it will be a more of light modding them both.
i also thought about to buy and mod two edelux, instead of the cyo r. pro that is, the better cooling, fewer optical losses and the different driver (it should be probably more effective), contra that is the missing nearfield, that i really need and the high price.
what do you think about all that?
my past experiences:
http://www.candlepowerforums.com/vb/showpost.php?p=3148452&postcount=9
Tino
the modding by placing better bins of the xp-g into it may not bring the wow-effect, but its more and makes fun. my plan is to drive two cyo-r on my new coming bike, so it will be a more of light modding them both.
i also thought about to buy and mod two edelux, instead of the cyo r. pro that is, the better cooling, fewer optical losses and the different driver (it should be probably more effective), contra that is the missing nearfield, that i really need and the high price.
what do you think about all that?
my past experiences:
http://www.candlepowerforums.com/vb/showpost.php?p=3148452&postcount=9
Tino
So if I understand correctly you have already dropped an MCE into your CYOR but it didnt work out? Aside from the obvious cooling issues of running at full tilt non-stop, if the setup was powered by lithium cells would you have been more satisfied?
BrianMc
Enlightened
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I like that someone is folllowing the mod a light that meets the German StVZO standards.
Someone in this thread, I think it may have been panicmechanic suggested the Phillips light as just begging for an LED upgrade, and it was less expensive than some other choices (circa $100).
My concern about the beam pattern of these lights stems from experience with a road beam experiment (ongoing, most recent post this page).
It is admirable that engineers harnessed the light of 3 watt generators putting as much of the light as possible where it would help a rider see. This holds true whether it is 3-4 watt halogens or early generation LEDs. So what concern do I have? It stems from being seen. This may be a function of whether you have bike lanes, a bike savvy motoring public, and an expectation by motorists that bikes are in the trafffic mix. I have none of these.
A video of my lights in the day with a snoot on the low beam to tame its medium wide beam, and the helmet light with its very narrow 8-11 degree full cut off beams showed that they were not showing up for a video camera at driver height in the oncoming lane unless I aimed the helmet light at the driver/camera. The night video was a bit better. Too many driver's did not see me or thought me a slow bicycle. Recent day and night video with the bar light unleashed from the snoot show it might be a bit too uncivilized in night use. Drivers wait till I ride by when they don't need to. This may be a good thing. I have had some moderate indications of dislike but no one gave me their high beams. I will do a drive by myself tonight to assess whether they have a beef or are just wimps. At 50% power the low is about as bright as a Magicshine and maybe a bit narrower but not by much. On full, it is close to 1.5 MJ-808's output.
Pe2er had a post in a thread here somewhere of his new Strada HPV which uses a StVZO standard main light and has fill led lights to add more spill or 'be seen ' light. It appears the concern about being seen with these lights has some support. My helmet light can be aimed in only one direction aat a time so it is not the answer to the problem when cars come from both sides. My high aimed at the driver has stopped at least three hooks that were beginning, though.
So, I pose it as a question: is the German StVZO liight standard a bit too effective and does it reduce a cyclist's visibility to motorists, especially in traffic situations where motorists rarely see cyclcists, so may need a bit more? If so, it would free your modding works some if you lived in a country where the standards do not apply. I may be a good thing if your resulting pattern is a bit broader. A thought.
Meanwhile I will see if I have an issue with the unfettered low beam that needs attention, or not. If it is uncomfortable but not blinding, that may be a very 'safe for me' setting. Just so long as a car full of really big angry weight lifters doesn't u-turn then overtake me to 'larn me a lesson' about using bright lights. 😗
Someone in this thread, I think it may have been panicmechanic suggested the Phillips light as just begging for an LED upgrade, and it was less expensive than some other choices (circa $100).
My concern about the beam pattern of these lights stems from experience with a road beam experiment (ongoing, most recent post this page).
It is admirable that engineers harnessed the light of 3 watt generators putting as much of the light as possible where it would help a rider see. This holds true whether it is 3-4 watt halogens or early generation LEDs. So what concern do I have? It stems from being seen. This may be a function of whether you have bike lanes, a bike savvy motoring public, and an expectation by motorists that bikes are in the trafffic mix. I have none of these.
A video of my lights in the day with a snoot on the low beam to tame its medium wide beam, and the helmet light with its very narrow 8-11 degree full cut off beams showed that they were not showing up for a video camera at driver height in the oncoming lane unless I aimed the helmet light at the driver/camera. The night video was a bit better. Too many driver's did not see me or thought me a slow bicycle. Recent day and night video with the bar light unleashed from the snoot show it might be a bit too uncivilized in night use. Drivers wait till I ride by when they don't need to. This may be a good thing. I have had some moderate indications of dislike but no one gave me their high beams. I will do a drive by myself tonight to assess whether they have a beef or are just wimps. At 50% power the low is about as bright as a Magicshine and maybe a bit narrower but not by much. On full, it is close to 1.5 MJ-808's output.
Pe2er had a post in a thread here somewhere of his new Strada HPV which uses a StVZO standard main light and has fill led lights to add more spill or 'be seen ' light. It appears the concern about being seen with these lights has some support. My helmet light can be aimed in only one direction aat a time so it is not the answer to the problem when cars come from both sides. My high aimed at the driver has stopped at least three hooks that were beginning, though.
So, I pose it as a question: is the German StVZO liight standard a bit too effective and does it reduce a cyclist's visibility to motorists, especially in traffic situations where motorists rarely see cyclcists, so may need a bit more? If so, it would free your modding works some if you lived in a country where the standards do not apply. I may be a good thing if your resulting pattern is a bit broader. A thought.
Meanwhile I will see if I have an issue with the unfettered low beam that needs attention, or not. If it is uncomfortable but not blinding, that may be a very 'safe for me' setting. Just so long as a car full of really big angry weight lifters doesn't u-turn then overtake me to 'larn me a lesson' about using bright lights. 😗
When running an StVZO compliant light, its probably a good idea to use an auxiliary LED flasher like the Blackburn FLEA. It's a great be-seen light...small, affordable, and motorists can easily see you without it screwing up their night vision.
Another important ingredient is reflective gear. I recently purchased some 3M Scotchlite "Lightweights Stealth Tape"...its awesome because its black until headlights hits it.
It's probably a good starting point. Compare it to projector headlights on cars - sharp cutoff and well-defined beam, but there is still adequate (upward) spill to be seen by other motorists.
As you said, most makers focus their beam tightly so that the central hotspot is the most efficient use of the limited power available. However the StVZO spec (as far as I can tell) does not limit the width of the beam, or downward projection of light. This is where a more powerful emitter will have benefits.
BrianMc
Enlightened
- Joined
- Nov 4, 2009
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We agree about the need for some spill. We may differ on the amount we need.
Running scotchlite white and red on fork/stays fender. Lightweights on spokes, pedals, helmet, ANSI vest with reflective striping. ANSI vest lights up like Neon in sunlight, too.
I want some respect beyond "Oh! Its just a bike." (thinking 5 mph) and pull out too close and with too little acceleration when I'm doing 20+ mph and 20 feet away, but something a bit friendlier than burn their retinas out. I may have that now or I may be a tad over the line.
I have not seen a 'be seen' light I think works well enough for my situation. On 55 mph roads (or 30 mph ones where they drive 55) they're too little, seen too late.
panicmechanic
Newly Enlightened
After some riding experience (well, still not enough...) with my light, I'm convinced that a light compliant to german standards needs to be accompanied by, at least, a high beam with a momentary switch if you're riding in high-speed motorized traffic. Also cornering on unlit roads will profit from additional light above the regulated cutoff line. Sadly, the regulations do not allow for a high beam. But then, who cares? Police here got enough important work to do and would only stop you if you're unlit in the dark, or if you burn their eyes with a constant high beam.
Sideways visibility can be greatly improved by directing a small portion of light into a transparent part of the housing, like in the current Trelock lights that use a light guide into the retroreflector. Holding your lens with an acrylic tube is another option.
Make sure the light comes out sideways only, any portion going directly into your eyes or onto parts of the bike will impair your night vision.
In the now historic era of standard and halogen light bulbs, the front lenses were often made as Fresnel lenses to spread the beam. The plastic was not exactly transparent, so it was lit by the bulb and gave side visibility.
A b&m headlight will improve in terms of lateral visibility as the lens gets dirty or scratched 😉 , whereas the Edelux offers no lateral visibility at all, due to the recessed lens. The high quality glass does not help either, as lateral visibility depends on refraction of beams.
@Matt King: that is also my understanding of german regulations. They define a center point, the highest lux value must be there (or another point must not be more than 20% brighter than the center). Apart from that, it's minimum values, only the cutoff line is heavily regulated.
So, if you find a setup that gives you a 20° horizontal bar of even brightness, you're done 🙂
By the way, I had my light measured recently, and it is well within the limits. The cutoff could even be less sharp and still comply. The definition allows for a max. of 2lx at or above 3.4° of the "0°" line.
Sideways visibility can be greatly improved by directing a small portion of light into a transparent part of the housing, like in the current Trelock lights that use a light guide into the retroreflector. Holding your lens with an acrylic tube is another option.
Make sure the light comes out sideways only, any portion going directly into your eyes or onto parts of the bike will impair your night vision.
In the now historic era of standard and halogen light bulbs, the front lenses were often made as Fresnel lenses to spread the beam. The plastic was not exactly transparent, so it was lit by the bulb and gave side visibility.
A b&m headlight will improve in terms of lateral visibility as the lens gets dirty or scratched 😉 , whereas the Edelux offers no lateral visibility at all, due to the recessed lens. The high quality glass does not help either, as lateral visibility depends on refraction of beams.
@Matt King: that is also my understanding of german regulations. They define a center point, the highest lux value must be there (or another point must not be more than 20% brighter than the center). Apart from that, it's minimum values, only the cutoff line is heavily regulated.
So, if you find a setup that gives you a 20° horizontal bar of even brightness, you're done 🙂
By the way, I had my light measured recently, and it is well within the limits. The cutoff could even be less sharp and still comply. The definition allows for a max. of 2lx at or above 3.4° of the "0°" line.
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BrianMc
Enlightened
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An alternative to a bar mount switchable high beam is a helmet mounted light and moving the head if the beam isn't too wide.
Last night confirmed that depending on tilt of light and grade of road, the 'low' I use is a bit much even on half power. It is not crippling, about half as bad as a car high beam not dipped. Older drivers with borderline night vision coud be badly affected, though. So another attempt to rein it in is in order.
Options 1 + 2 require a new light build. I have retired a pair of plastic fresnel lens halogen lamps that give a sharp cutoff that were kept as possible donors. So thanks for the reinforcement to experiment with them.
Nice chart. Well done.
panicmechanic
Newly Enlightened
I have to thank Olaf Schultz for the work. Here's more. He tested many older and current consumer lights and some homegrown ones for their compliance to german regulations. A lot to learn there if you spend some time.
Sorry for the dumb question...my education is all chemistry. Nothing stops us from powering a pre-fab cyo or edelux generator light with lithium cells, does it?
BrianMc
Enlightened
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A quick report.
Cut out the center of the front lens of a halogen lamp with prism lens. (Pictures later, if road test pans out) to fit bezel of Marwi low beam light head. Compared at the wall shots of no lens versus prism. Can get a vertical oriented central beam or with lens at right angles to that, a mostly below horizon somewhat horizontal beam. In this horizontal mode, one LED wants to shoot low, sort of like the close fill in of the one Cyo light. It does cut the top off the beam significantly. (Photos of night wall shots with target and light meter if it works on the road.) Was concerned the beam shaping by the reflector was essential or the triangular three LED arrangement would make it ineffective. SO far looking 'plausible'.
Will ride it and do the walk (simulation of drive) by, if it merits, the above shots and video.
Cut out the center of the front lens of a halogen lamp with prism lens. (Pictures later, if road test pans out) to fit bezel of Marwi low beam light head. Compared at the wall shots of no lens versus prism. Can get a vertical oriented central beam or with lens at right angles to that, a mostly below horizon somewhat horizontal beam. In this horizontal mode, one LED wants to shoot low, sort of like the close fill in of the one Cyo light. It does cut the top off the beam significantly. (Photos of night wall shots with target and light meter if it works on the road.) Was concerned the beam shaping by the reflector was essential or the triangular three LED arrangement would make it ineffective. SO far looking 'plausible'.
Will ride it and do the walk (simulation of drive) by, if it merits, the above shots and video.
A possible solution?
http://www.photonicsonline.com/article.mvc/ReflectorCAD-Simplifies-Segmented-Reflector-D-0001
Watch the demo on this page (I am regretting forgoing engineering at this point)
http://www.breault.com/software/reflectorCAD.php
http://www.photonicsonline.com/article.mvc/ReflectorCAD-Simplifies-Segmented-Reflector-D-0001
Watch the demo on this page (I am regretting forgoing engineering at this point)
http://www.breault.com/software/reflectorCAD.php
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BrianMc
Enlightened
- Joined
- Nov 4, 2009
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- 940
Panicmechanic used a aspheric lens for his pattern (nicely done BTW). The thread is currently discussing the reflector method, and I applaud that. I submit this not to detract from that discussion, but to complete prior work posted in this thread, and to evaluate the fresnel/prism lens approach in making a beam approximating the German standards. This is something I had thought of when I first saw the beam pattern of these halogen lights, but only recently has the need become imperitive and then I got a seconding of the idea a few posts up.
The low beam light is the one on the left with three CREE XPG R5 and three Carclo 10417 lenses:
Suppposedly 16.5 degrees FWHM with the XR-E, these lenses are in the 18-20 degree FWHM range with the XP-G.
I sacrificed the center of the fresnel/prism lens from one of these bulbs.
The right bulb is missing its lens center now mounted in the light's bezel in front of it, former glass cover in front of that.
The light was aimed so it gave the best road coverage for the glass cover lens as it was previously ridden. Two sets of pictures were taken one at 500 mA, my usual meeting traffic setting, the second at 1 A. I backed the camera exposure to the lowest setting in the first case, but the camera did not keep the same setting, varying the exposure with the amount of light. In the second set and the last picture of the adjusted light, the camera was left on it normal exposure. The fresnel/prism lens makes a horizontal cutoff beam in one direction and a vertical beam with side cutoff at 90 degrees. Both settings were tested, as was no lens at all.
http://imageshack.us
After the shots of the light in the aim I used before, the aim was reset to get best use of the changed beam and another picture taken:
The lampost light has about 6-800 lumens shining in a 360 degree pattern.
Huge improvement on what I had regardless of how close it comes to the German standard. As far as side view goes, the large bright patch of light this makes precedes the bike by several seconds and the reflective tape on the wheels and front fork outshine the tail lights when car headlights shine on them.
The indoor beamshots with light meter and a video of the modded light in action remain to be done to characterize the changes made. It looks like there should be enough spill for day running light use, but that is another evaluation.
The low beam light is the one on the left with three CREE XPG R5 and three Carclo 10417 lenses:
Suppposedly 16.5 degrees FWHM with the XR-E, these lenses are in the 18-20 degree FWHM range with the XP-G.
I sacrificed the center of the fresnel/prism lens from one of these bulbs.
The right bulb is missing its lens center now mounted in the light's bezel in front of it, former glass cover in front of that.
The light was aimed so it gave the best road coverage for the glass cover lens as it was previously ridden. Two sets of pictures were taken one at 500 mA, my usual meeting traffic setting, the second at 1 A. I backed the camera exposure to the lowest setting in the first case, but the camera did not keep the same setting, varying the exposure with the amount of light. In the second set and the last picture of the adjusted light, the camera was left on it normal exposure. The fresnel/prism lens makes a horizontal cutoff beam in one direction and a vertical beam with side cutoff at 90 degrees. Both settings were tested, as was no lens at all.
http://imageshack.us
After the shots of the light in the aim I used before, the aim was reset to get best use of the changed beam and another picture taken:
The lampost light has about 6-800 lumens shining in a 360 degree pattern.
Huge improvement on what I had regardless of how close it comes to the German standard. As far as side view goes, the large bright patch of light this makes precedes the bike by several seconds and the reflective tape on the wheels and front fork outshine the tail lights when car headlights shine on them.
The indoor beamshots with light meter and a video of the modded light in action remain to be done to characterize the changes made. It looks like there should be enough spill for day running light use, but that is another evaluation.
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Sadly the price of these sort of CAD packages is in the "if you have to ask" range... Plus you then need a 3D design CAD package on top of that to complete the mechanical design.
Of course if you want to lend me the money I'll give it a crack. (Mech engineer here, with some background experience and contacts with optics engineers)
