what headtorch?
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Re: what headtorch?
AR, did Grubby not understand your article or are you getting it really really tidy before sending it in? Enquiring minds are still waiting to know more...
- swat
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Re: what headtorch?
No, grubby understood AR's article perfectly. It's most informative. I'm sure AR will get around to putting it online shortly.
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grubby - light green
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Re: what headtorch?
I hope so as my Christmas pressie is still on hold (no pressure though )
- swat
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Re: what headtorch?
Has anything happened on this? I'm interested in building my own headlamp. I'm new to orienteering and even newer to night orienteering. I'm not keen on the cheaper feeble lights and rather shocked at the price of the more serious ones.
I'm thinking about using a 20W PAR36 bulb (either 6v or 12v) powered by 20 x 2800mAH rechargeable AA batteries. Anyone else have any experience of this type of setup?
I'm thinking about using a 20W PAR36 bulb (either 6v or 12v) powered by 20 x 2800mAH rechargeable AA batteries. Anyone else have any experience of this type of setup?
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Wayward-O - light green
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Re: what headtorch?
Big problem for me has been building the housing. I finished my setup last week and the 3x seoul LEDS were burning very bright. I tested in the forest and it worked pretty well. I made some changed and wrecked the whole housing. I think you really need to start with an old torch and modify it. Problem is that the seoul leds burn pretty hot so you need a whacking great heatsink to stop your head from melting.
Another option is upgrading your expensive torch with the following lamp:
http://www.sport8.no/butikk/index.php?a ... ductId=191
Think it voids your warranty and might melt the housing but I bet you its pretty bright!
Another option is upgrading your expensive torch with the following lamp:
http://www.sport8.no/butikk/index.php?a ... ductId=191
Think it voids your warranty and might melt the housing but I bet you its pretty bright!
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pyrat - [nope] cartel
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- Joined: Wed Oct 22, 2003 12:02 am
Re: what headtorch?
I hope Chris doesn't mind me publishing this. It's his email to me re: lighting
This should keep some of you happy. I think you miss the point though. The way forward is to have a special light for 'Stealth Mode'. You know the scenario. . . . . . you're in a 'posse'. . . . . you see the control 35-40m away, before anyone else. . . . . . . do you turn your light off and stumble towards it. . . . . . or try and nip in quick and away. . . . . . . . Near 'infra red'. . . . it's the way forward !
From AR
As I've mentioned before, the biggest issue you have is getting a housing to put them into. There are a few different options, which I'll come onto in a bit, but just bear in mind that does affect the other parts of the build. I presume you can for now do as I have and mount it to a Silva headstrap with zip-ties (I'm working on a new headstrap, but not there yet).
LEDs: For home builds there are only two high performance options at the moment, the Cree XR-E or the SSC P4. Forget anything by Luxeon - you'll still see Luxeon 3s or Luxeon 5s advertised by UK shops as the best performing, but they are less than half as bright as the more modern options which came out about a year ago (when I first started on this). My O light uses XR-Es, and that's what most other people seem to be using for homebuilds too (they have a slight performance edge). You can either get LEDs as bare emitters or mounted on a PCB - the latter is a much better option for homebuilding, as they're much easier to deal with.
Optics: You basically have two options here, either individual optics for each LED, or a multi LED optic which works with 3 LEDs (there are also options for 4 LEDs, but nothing readily available which will work well at the moment). This is your first fundamental choice, and dependent on what you're putting them in - for a multi LED optic you really want a casing the same size as the optic - for individual optics a casing big enough to fit them in. With individual optics you also need a plastic / glass front window to seal it (with multi-optics the optic itself should seal against the case). I'll also suggest at this point that you go for 3 LEDs, as there isn't a huge advantage to 4, and it's much easier to build with 3 (my first attempt I used last season only had 3). I'm using individual optics.
Casing: The crucial thing here is to use something which you will transfer the heat from the LEDs, as they like to stay cool, but you are pumping lots of energy into them, most of which does turn into heat. The best material for this is aluminium, since it conducts heat well, but is still light (copper is an alternative for heat conduction, but heavy). You do have to mount the LEDs (or PCB) to something which will conduct the heat to the outside of the casing - my solution to this is to mount the LEDs directly to the back of the case, and just use a short can. In fact I'm using one of http://cgi.ebay.co.uk/12-Glass-Topped-A ... QQihZ018QQ for my current light (it needs trimming down just a tiny bit to make the LEDs a snug fit). Can't say it's perfect, as I've managed to break the glass in a lid (obviously I do tend to throw it round a bit). My first attempt used the tin from http://www.healthcheckpharmacy.com/shop ... ductid=640 cut down and with a hole cut in the lid and a bit of perspex glued in. I've also stuck a PC heatsink to the back of my casings to get the heat out better - I suspect this may be overkill as it stays icy cold when out running, only getting hot on the bench.
Electronics: There are several different ways to drive the LEDs. The simplest is to just connect them straight to a battery with a resistor in between - for this you need a battery which is higher voltage than the LEDs - 3 LEDs are typically 3.5V each (though this varies from 3.3V up to over 4V each), so 10.5V in total, so you'd need at least a 12V battery. Alternatively, and what most people are using is a constant current driver which is a bit of electronics which provides the LEDs with a set current (to drive LEDs you give them a fixed current and don't worry about the voltage). You can either get drivers which work from a higher voltage battery, so again you'd need a 12V battery, or ones which work from a lower voltage - in which case you can use your existing Silva battery. I use the latter type and a 7.2V battery. There are two different types of these drivers, either a simple design which just switches on and off (and may also allow you to vary the drive current by a switch to give two different levels), or those which operate on a push button with a little microprocessor controlling levels, and also giving you other functions such as warning when the battery is getting low. Again I use the latter type.
Casing part 2 (I did say it was the complex bit!) - you need something to put your driver in. The bike light builders tend to put it in the same can with a longer can, but I have mine external in a plastic box (there isn't space with the housing I use). For details and pictures of my mark1, see http://www.candlepowerforums.com/vb/sho ... p?t=147395
LEDs part 2: There are different bins for these high power LEDs. The bins are how the LEDs are sorted into different brightness levels, with performance gradually improving - my first build was with P3 bin (74 lumens), my latest with Q2 bin (87 lumens), whilst the current best are R2 bin (107 lumens). You pay more for higher bins, and whilst brighter is better, because of the way the eye works, it's actually quite hard to tell the difference between 87 and 107 lumens!
Sourcing, LEDs: I bought my LEDs from http://cutter.com.au/proddetail.php?prod=cut651 , where you can specify exactly the bin you want. Alternatively it seems they are now available at Farnell or RS in the UK, but the problem with those sources is that they come as bare LEDs, not on PCBs, and believe me unless you're a real soldering expert you don't want to be dealing with those. There is another source for these on PCBs in Germany http://www.led-tech.de/en/High-Power-LE ... 20_77.html which may be a bit faster delivery (though delivery from Cutter isn't that slow).
Sourcing, optics: I'm using http://cutter.com.au/proddetail.php?prod=cut680 - various other options http://cutter.com.au/search.php?nobox=& ... rice=&pg=1
Sourcing drivers: I'm using drivers from http://www.taskled.com/ The Fatman is a basic board which will work with a lower voltage (Silva) battery using just a switch to turn on and/or select different levels. The MaxFlex is a pushbutton controlled microprocessor based driver. Unfortunately he is out of stock of the Maxflex at the moment, and won't be shipping until January.
Sourcing all in one kits: One very good option is http://cutter.com.au/proddetail.php?prod=cut756 or http://cutter.com.au/proddetail.php?prod=cut757 which is what a lot of the bike light homebuilders are using. Comes with all the bits you need, including a triple lens - you just need to find a housing to suit it. The first version is with the basic Fatman, the second with either the Maxflex, or the bFlex (which requires a higher voltage battery). If you can get (or make) a suitable housing I'd suggest one of these kits may be the best and simplest option. Would probably work with the housing I use, though ideally you want something a bit smaller, as it will be rather lost in the middle (the kit is 35mm diameter, my can is 53mm) - I'm sure if you have a good look there is probably something out there.
Alternative sourcing option: I have a variety of LEDs and other parts sitting in my bits collection. I have Q2 bin LEDs on PCBs, the optics I mention above which I am currently using, and I also have some of the housings (which I could cut down for you - my dremel is currently set up to do this). I hasten to add I'm not trying to make money on this, and will sell to you at either my cost price, or whatever the current online price is, whichever is less. All of these are brand new unused - I bought a load thinking I was going to make more lights for other people and have never found the time. Of course the LEDs I have aren't the very latest, brightest ones, but they're what I'm using. I also have a Maxflex driver, which I was going to use myself, but so far I've just used it briefly for testing, so is all but brand new - if you are interested I can also sell you this for what I paid for it, and I will get another one later, as I'm certainly not going to want to install it before January.
Phew - hope that was helpful - I have a feeling there are more questions than answers there. If you want more detail, or more simplification of any of it, or I've just missed something, then please get back to me!
This should keep some of you happy. I think you miss the point though. The way forward is to have a special light for 'Stealth Mode'. You know the scenario. . . . . . you're in a 'posse'. . . . . you see the control 35-40m away, before anyone else. . . . . . . do you turn your light off and stumble towards it. . . . . . or try and nip in quick and away. . . . . . . . Near 'infra red'. . . . it's the way forward !
From AR
As I've mentioned before, the biggest issue you have is getting a housing to put them into. There are a few different options, which I'll come onto in a bit, but just bear in mind that does affect the other parts of the build. I presume you can for now do as I have and mount it to a Silva headstrap with zip-ties (I'm working on a new headstrap, but not there yet).
LEDs: For home builds there are only two high performance options at the moment, the Cree XR-E or the SSC P4. Forget anything by Luxeon - you'll still see Luxeon 3s or Luxeon 5s advertised by UK shops as the best performing, but they are less than half as bright as the more modern options which came out about a year ago (when I first started on this). My O light uses XR-Es, and that's what most other people seem to be using for homebuilds too (they have a slight performance edge). You can either get LEDs as bare emitters or mounted on a PCB - the latter is a much better option for homebuilding, as they're much easier to deal with.
Optics: You basically have two options here, either individual optics for each LED, or a multi LED optic which works with 3 LEDs (there are also options for 4 LEDs, but nothing readily available which will work well at the moment). This is your first fundamental choice, and dependent on what you're putting them in - for a multi LED optic you really want a casing the same size as the optic - for individual optics a casing big enough to fit them in. With individual optics you also need a plastic / glass front window to seal it (with multi-optics the optic itself should seal against the case). I'll also suggest at this point that you go for 3 LEDs, as there isn't a huge advantage to 4, and it's much easier to build with 3 (my first attempt I used last season only had 3). I'm using individual optics.
Casing: The crucial thing here is to use something which you will transfer the heat from the LEDs, as they like to stay cool, but you are pumping lots of energy into them, most of which does turn into heat. The best material for this is aluminium, since it conducts heat well, but is still light (copper is an alternative for heat conduction, but heavy). You do have to mount the LEDs (or PCB) to something which will conduct the heat to the outside of the casing - my solution to this is to mount the LEDs directly to the back of the case, and just use a short can. In fact I'm using one of http://cgi.ebay.co.uk/12-Glass-Topped-A ... QQihZ018QQ for my current light (it needs trimming down just a tiny bit to make the LEDs a snug fit). Can't say it's perfect, as I've managed to break the glass in a lid (obviously I do tend to throw it round a bit). My first attempt used the tin from http://www.healthcheckpharmacy.com/shop ... ductid=640 cut down and with a hole cut in the lid and a bit of perspex glued in. I've also stuck a PC heatsink to the back of my casings to get the heat out better - I suspect this may be overkill as it stays icy cold when out running, only getting hot on the bench.
Electronics: There are several different ways to drive the LEDs. The simplest is to just connect them straight to a battery with a resistor in between - for this you need a battery which is higher voltage than the LEDs - 3 LEDs are typically 3.5V each (though this varies from 3.3V up to over 4V each), so 10.5V in total, so you'd need at least a 12V battery. Alternatively, and what most people are using is a constant current driver which is a bit of electronics which provides the LEDs with a set current (to drive LEDs you give them a fixed current and don't worry about the voltage). You can either get drivers which work from a higher voltage battery, so again you'd need a 12V battery, or ones which work from a lower voltage - in which case you can use your existing Silva battery. I use the latter type and a 7.2V battery. There are two different types of these drivers, either a simple design which just switches on and off (and may also allow you to vary the drive current by a switch to give two different levels), or those which operate on a push button with a little microprocessor controlling levels, and also giving you other functions such as warning when the battery is getting low. Again I use the latter type.
Casing part 2 (I did say it was the complex bit!) - you need something to put your driver in. The bike light builders tend to put it in the same can with a longer can, but I have mine external in a plastic box (there isn't space with the housing I use). For details and pictures of my mark1, see http://www.candlepowerforums.com/vb/sho ... p?t=147395
LEDs part 2: There are different bins for these high power LEDs. The bins are how the LEDs are sorted into different brightness levels, with performance gradually improving - my first build was with P3 bin (74 lumens), my latest with Q2 bin (87 lumens), whilst the current best are R2 bin (107 lumens). You pay more for higher bins, and whilst brighter is better, because of the way the eye works, it's actually quite hard to tell the difference between 87 and 107 lumens!
Sourcing, LEDs: I bought my LEDs from http://cutter.com.au/proddetail.php?prod=cut651 , where you can specify exactly the bin you want. Alternatively it seems they are now available at Farnell or RS in the UK, but the problem with those sources is that they come as bare LEDs, not on PCBs, and believe me unless you're a real soldering expert you don't want to be dealing with those. There is another source for these on PCBs in Germany http://www.led-tech.de/en/High-Power-LE ... 20_77.html which may be a bit faster delivery (though delivery from Cutter isn't that slow).
Sourcing, optics: I'm using http://cutter.com.au/proddetail.php?prod=cut680 - various other options http://cutter.com.au/search.php?nobox=& ... rice=&pg=1
Sourcing drivers: I'm using drivers from http://www.taskled.com/ The Fatman is a basic board which will work with a lower voltage (Silva) battery using just a switch to turn on and/or select different levels. The MaxFlex is a pushbutton controlled microprocessor based driver. Unfortunately he is out of stock of the Maxflex at the moment, and won't be shipping until January.
Sourcing all in one kits: One very good option is http://cutter.com.au/proddetail.php?prod=cut756 or http://cutter.com.au/proddetail.php?prod=cut757 which is what a lot of the bike light homebuilders are using. Comes with all the bits you need, including a triple lens - you just need to find a housing to suit it. The first version is with the basic Fatman, the second with either the Maxflex, or the bFlex (which requires a higher voltage battery). If you can get (or make) a suitable housing I'd suggest one of these kits may be the best and simplest option. Would probably work with the housing I use, though ideally you want something a bit smaller, as it will be rather lost in the middle (the kit is 35mm diameter, my can is 53mm) - I'm sure if you have a good look there is probably something out there.
Alternative sourcing option: I have a variety of LEDs and other parts sitting in my bits collection. I have Q2 bin LEDs on PCBs, the optics I mention above which I am currently using, and I also have some of the housings (which I could cut down for you - my dremel is currently set up to do this). I hasten to add I'm not trying to make money on this, and will sell to you at either my cost price, or whatever the current online price is, whichever is less. All of these are brand new unused - I bought a load thinking I was going to make more lights for other people and have never found the time. Of course the LEDs I have aren't the very latest, brightest ones, but they're what I'm using. I also have a Maxflex driver, which I was going to use myself, but so far I've just used it briefly for testing, so is all but brand new - if you are interested I can also sell you this for what I paid for it, and I will get another one later, as I'm certainly not going to want to install it before January.
Phew - hope that was helpful - I have a feeling there are more questions than answers there. If you want more detail, or more simplification of any of it, or I've just missed something, then please get back to me!
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grubby - light green
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Re: what headtorch?
No worries, Andy - I just don't have the time nowadays to get round to making that more like a proper article - hope it's of some use to people, and still looking for better housing suggestions (or best of all somebody with access to a CNC lathe ) As I said when I sent that if there are any questions I can probably answer most of them (as can Ifor now I suspect - he's becoming as much of an expert on this as me!)
British candle-O champion.
- Adventure Racer
- addict
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Re: what headtorch?
I am planning to do a writeup with pictures of my stuff for the flashaholics once I get time. I will put a link here once I have. My housings are all made from bits of Aluminium from B&Q and glued with arctic silver. I have been using square lenses, my stuff is based off this clasic design http://bikeled.org/ there are lots of people with variations on this for bikes. The square housing means it's fairly easy for DIY. Chacing the bits from all over the world is a bit of fun. The major hazzard is getting addicted which I have not been doing a very good job of avoiding with not being fit to run like I have been in the past.
Ifor
Ifor
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ifor - brown
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Re: what headtorch?
All very interesting stuff and my home made narrow-beam 12V dichroic halogen (20W, 10 degrees) over volted at 14.4V now looks very old-fashioned indeed. I would love to construct a LED replacement as per instructions, but I wonder what the power consumption of, say, a 3 LED setup is? Will my 4.5 AH twin 7.2V (nominal, actually over 8V each when fully charged) NiMH batteries still give me a reasonable time before the light runs out? I can run for about 2 hrs now which is about long enough for most events at my speed.
You may gather that I have next to no knowledge of electronics, but can just about solder a simple circuit.
You may gather that I have next to no knowledge of electronics, but can just about solder a simple circuit.
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Zokko! - yellow
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Re: what headtorch?
OK, that's a nice easy one to start with. If you run one of these LEDs at full whack it's ~3.5W, so 3 will be ~10.5W. If you allow for a driver which is typically ~90% efficient, that's ~12W in total. 4.5Ah 7.2V gives 32Wh - if I'm reading correctly you use 2 of these, so that's a total of 64Wh, or about 5.5 hours of light running those LEDs! What this means is that you could actually dump one of your batteries, as one on its own will still give you 2.7 hours - simply use a boost driver (see links above) to run 3 LEDs from a 7.2V nominal battery. That's one big advantage of LEDs, that you can use smaller batteries - noting that the 3 LEDs will be significantly brighter than an overvolted 20W halogen (I actually use a tiny LiIon battery which weighs 100g and fits in my trouser pocket, so no battery bag - only gives me 1h20 runtime, but I don't normally need more).
British candle-O champion.
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Re: what headtorch?
Wow!!! LEDs are definitely the way to go. I've now surfed around and I'm much better informed about these little babies than I was. Need to sort out the light-to-head interface, though.
Tried a search on eBay to see what's out there on the auctions, etc. and turned up some interesting looking flashlights (torches) built around this technology (3x CREE LEDs), the cheapest of which are less than £30.00 delivered (from HK or China). Examples are:
http://cgi.ebay.co.uk/UltraFire-500Lume ... dZViewItem
http://cgi.ebay.co.uk/500-Lumen-CREE-LE ... dZViewItem
http://cgi.ebay.co.uk/SpiderFire-550-lu ... dZViewItem
http://cgi.ebay.co.uk/4x-CREE-600-Lumen ... dZViewItem
Has anyone used one of these as the basis for a headtorch rather than the completely scratchbuilt approach?
Tried a search on eBay to see what's out there on the auctions, etc. and turned up some interesting looking flashlights (torches) built around this technology (3x CREE LEDs), the cheapest of which are less than £30.00 delivered (from HK or China). Examples are:
http://cgi.ebay.co.uk/UltraFire-500Lume ... dZViewItem
http://cgi.ebay.co.uk/500-Lumen-CREE-LE ... dZViewItem
http://cgi.ebay.co.uk/SpiderFire-550-lu ... dZViewItem
http://cgi.ebay.co.uk/4x-CREE-600-Lumen ... dZViewItem
Has anyone used one of these as the basis for a headtorch rather than the completely scratchbuilt approach?
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Wayward-O - light green
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- Joined: Fri Feb 08, 2008 10:26 pm
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Re: what headtorch?
The problem with the standard torches is that you would have a hard time making them into a headlight they are quite long and heavy. You can mount them on a Bike helment and bike bars and people have done this. Thre are a cheap options from hong-kong http://www.dealextreme.com/products.dx/category.901 Clive Hallet has won many a night event in the past with a huge 2 or 3 pound hand tourch so using a hand tourch is not imposible but not recomended.
Anyway I just posted some text and pictures about the lights I have done so some people may be interested. I can answer O specifc questions here.
http://www.candlepowerforums.com/vb/sho ... ost2381308
Anyway I just posted some text and pictures about the lights I have done so some people may be interested. I can answer O specifc questions here.
http://www.candlepowerforums.com/vb/sho ... ost2381308
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ifor - brown
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Re: what headtorch?
Ifor, I wasn't thinking of just strapping a flashlight to my head.
As these torches unscrew into sections, I was thinking about mounting the front section with the LEDs on a headstrap and wiring this to a separate battery pack.
As these torches unscrew into sections, I was thinking about mounting the front section with the LEDs on a headstrap and wiring this to a separate battery pack.
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Wayward-O - light green
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Re: what headtorch?
AR / Ifor / Everybody
Great set of posts and links!! Thanks for all the info - I'm going to have to get my thinking cap on and start playing around. Night season's nearly over so I've got a few months tinkering time.
Great set of posts and links!! Thanks for all the info - I'm going to have to get my thinking cap on and start playing around. Night season's nearly over so I've got a few months tinkering time.
- swat
- orange
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- Joined: Wed Dec 22, 2004 1:33 pm
- Location: Bramley
Re: what headtorch?
I don't want to rain on the homebuilt parade, but for anyone after an orienteering lamp using LED technology, there is a new offering in the pipe line from Petzl. The 'Ultra' uses six Seoul P4 LEDs. Much loved by bike light manufacturers like Lupine, these improve on the output of Luxeon III or even CRE XR-E LEDs. The lamp is designed specifically for night orienteering, so beam angle, distance and colour is designed with this in mind.
I have tried it on a night event in the Lakes - it seemed the dogs knob. Thought I can't personally compare to it SIlva/Mila models, with 350 lumens of output it should rank pretty well. Of course the efficiency of LEDs gives improved burn times compared to incandescents.
Pros: Plenty
Cons: Not in the shops yet, costs a few quid, you don't get to tinker with a soldering iron.
I have tried it on a night event in the Lakes - it seemed the dogs knob. Thought I can't personally compare to it SIlva/Mila models, with 350 lumens of output it should rank pretty well. Of course the efficiency of LEDs gives improved burn times compared to incandescents.
Pros: Plenty
Cons: Not in the shops yet, costs a few quid, you don't get to tinker with a soldering iron.
- scottA
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