# DIY-project: Headlamp with 6 XML-leds!



## Challe_ (Aug 27, 2011)

Hi!

I may be in wrong section, but at least it will be a homemade headlamp for orienteering (running in the forest).

It will be my first DIY-project, I have looked around at this forum for a while and got many questions answered, but there are still some questions left. I want really strong and wide light. Theoretical 6000/8000 lumens sounds fair to me.

So far I have planned building my headlamp with 6 or 8 pieces of XM-L T6: http://www.dealextreme.com/p/xmlawt-1000-lumen-led-emitter-white-light-bulb-3-0-3-5v-51989 and use lenses with different angles from Ledil: http://ledil.com/node/2/p/1348 I'm not sure about the efficiency, but i hope it's around atleast 90%.. The only problem is the website i will order from have 45days ordertime: http://www.newark.com/ledil . Right now I want to screw it through the heatsink so it want fall off. But maybe tape or glue is strong enough too? What do you say?

For constant power I'm thinking of using this driver: http://www.dotlight.de/products/fr/...constant-current-source-KONLUX-DC-3000mA.html I have planned using 2 drivers with 3 or 4 leds in series.

And as battery I will make 3 "batteries" in series with 4/5 cells per serie (depending on how many emitters i will use) with something like: http://www.dealextreme.com/p/asucel...-3000mah-lithium-18650-batteries-2-pack-42153 I want batteries with atleast 3000mAh so i can run my headlamp for 90 minutes (battery: 9000mAh, 14.8V/18,5V). I have looked for AW and pila-batteries bit i think they are too expensive for me.

As heatsink for the emitters i want something like: http://coolingtower-design.com/wp-content/uploads/2011/01/heatsink.jpg which is maybe length 12cm, heigth 7cm and deep 2cm. Maybe you have a website with heatsinks, suggests with different sizes would be very nice!

Now I have some questions: 
Do you suggest another driver and battery instead of the driver and battery I suggested? It seems that driver drops too much and the battery don't have the capacity It would be very nice if you have a suggestion of a driver which has 2+ modes.. The driver I suggested, does it recognize how many emitters I put in series?

Maybe you suggest other lenses and emitters with good efficiency and lumen per watt?

I have a budget on like 400$, absolute max 500$. The cheaper, the better, but I want something that works. I'm thankful for help in advance!


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## simplec6 (Aug 27, 2011)

Awesome idea man, I hope to make a 6 XML U2 mag lite soon after I find a source for a huge heatsink/head. I plan to do them in 3 series, 2 parallel and use an H6Flex driver with 4 32500's in a Mag 4D.

Please keep us updated on your build!


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## ahorton (Aug 27, 2011)

Sounds interesting and I'll watch with interest. 

Having made a few headlamps, I have one big suggestion: Make a mock-up of everything except the electronics. See how you go for weight, comfort and balance. My prediction is that if the heat exchanger can handle more than 10W/1000lumens then it will be too heavy and unbalanced. I made a 2000lumen headlamp once. It was too heavy for running and still overheated. 

Next bit of advice is that you do some meaningful comparisons before buying all that gear. Find a 1000 lumen light and then work out if you really need any more flux. A well made 1000 lumen light will probably give you a more useful beam than your car headlights on high. 

If you still want 6000lumens, then we can talk about your gear choices.


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## Techjunkie (Aug 27, 2011)

6 XML @ full blast on your head? You'll set your hair on fire!


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## shhh (Aug 27, 2011)

How about in the form of a vest? Then have a smaller headlamp also.


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## cdrake261 (Aug 27, 2011)

Techjunkie said:


> 6 XML @ full blast on your head? You'll set your hair on fire!


 
The song "ring of fire" by jonny cash comes to mind


Seriously though, my single xm-l mini mag will burn your hand if on for an extended amount of time


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## Challe_ (Aug 28, 2011)

ahorton said:


> Sounds interesting and I'll watch with interest.
> 
> Having made a few headlamps, I have one big suggestion: Make a mock-up of everything except the electronics. See how you go for weight, comfort and balance. My prediction is that if the heat exchanger can handle more than 10W/1000lumens then it will be too heavy and unbalanced. I made a 2000lumen headlamp once. It was too heavy for running and still overheated.
> 
> ...


 

I already have a Betty Lupine with 1850 lumen and today's Bettys is upgraded to 2600 lumen, and the today's LEDX cobra have 2500 lumen. So I'm not interested of something below 5000 theoretical lumen. I want a nice lamp which surprise everyone who see's it 

Don't forget that I'm going to run with the headlamp so it will be active cooling, and i will only use it in the autumn, winter and spring. It's cold here in sweden these times  For important competitions I will use the Betty Lupine so the weight wont be a big problem.


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## Challe_ (Aug 28, 2011)

I forgot to say that I will make this as a school-project.

Maybe I was asking too many questions. The most important for me to know is if you have a battery which gives nearly 3000mAh and isn't to expensive. I'm going to buy 12+ batteries if there are any website which gives a good price for a mass-order.

The second question is if you have a stepless (or with 2+modes) driver which gives at max 6A or a good 3A driver which don't drops too much (then i will use 2 drivers).

The third question is if you may give me a website for different sizes of heatsinks like http://coolingtower-design.com/2011/01/19/heatsink-2/ I couldn't find anything on dealextreme. (Maybe I have to order some smaller heatsinks for my drivers which i will place at the neck)

Thanks!


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## cdrake261 (Aug 28, 2011)

Challe_ said:


> I already have a Betty Lupine with 1850 lumen and today's Bettys is upgraded to 2600 lumen, and the today's LEDX cobra have 2500 lumen. So I'm not interested of something below 5000 theoretical lumen. I want a nice lamp which surprise everyone who see's it
> 
> Don't forget that I'm going to run with the headlamp so it will be active cooling, and i will only use it in the autumn, winter and spring. It's cold here in sweden these times  For important competitions I will use the Betty Lupine so the weight wont be a big problem.


 


Challe_ said:


> I forgot to say that I will make this as a school-project.
> 
> Maybe I was asking too many questions. The most important for me to know is if you have a battery which gives nearly 3000mAh and isn't to expensive. I'm going to buy 12+ batteries if there are any website which gives a good price for a mass-order.
> 
> ...


 
Sounds to me you need to do more reading


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## Challe_ (Aug 28, 2011)

cdrake261 said:


> Sounds to me you need to do more reading




Please specify what you mean with "need to do more reading", what am I missing? You are quoting 2 of my latest comments..


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## cdrake261 (Aug 28, 2011)

1) one xm-l at 3mps gets hot, 6 xm-l's is about 6 times hotter.

2) heatsinking to run those at 3amps for longer then 10 sec will be heavy

3) the batteries you would need to run those for any long amount of time will be heavy.

4) you say a single mode driver at 6 amps which is beyond being efficient unless you are running 2p3s or two 3amp driver running two set of 3 xm-l in series.

5) unless you are setting up 18650's parallel sets of series, your run time will be short.

6) you will need to check if your batteries can handle amperage output

7) wires

8) how you plan to charge your batteries

If I understood correctly, it sounds like you want this as a headband kind of setup while you run....I have my doubts this will work, but I'll tip my hat to you if you can get it to work.


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## sn0wBLiND (Aug 28, 2011)

I don't mean to sound too negative but how are you going to fit 6-8 of those 35mm optics onto your forehead?
And you'd basically need a metal helmet to keep those LED:s cool enough.
As for the batteries you could get proper panasonic/sanyo/LG cells fairly cheap but those are unprotected and I'm not sure if you are concerned enough about the safety hazards they bring to this project, although they are less likely to vent in flames in your pocket.


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## ahorton (Aug 28, 2011)

I think you'll profit more by doing some extra running training. You'll need to be fitter and stronger to carry the full aluminium helmet and battery backpack.

Have you read the 18650 reviews in the battery part of CPF? They will tell you what you need to know about your cell choice. Personally I'd be going for a RC LiPo pack if you want an hour or more runtime.


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## Challe_ (Aug 29, 2011)

I we're counting the weight of the battery, which should weight around 1kg if i use 6 xmls (12 cells, 66gram each). then i should have 3 x 4cells in series = "9Ah" at 14,8V. Of course I will modify the battery so i can use only "6Ah" and "3Ah" and then go for half of the power of my headlamp.

As i said, this is going to be my first diy-project. Is there any recommendation about heatsink per emitter for xm-l? Is it possible to count on the weight for the heatsink?

The good thing for me with the heavy headlamp is that i need the training with extra weight, and it will feel a lot easier to run when you don't wear it. 

I have got a enquiry for a headlamp with 3 or 4 xm-l leds, maybe this will be a good start as a prototype? Then i need a driver with stepless or 3modes or something like that, at max. 3A. I have hardly problems to find a driver that have these qualifications on my own.. I would be very grateful for a tip!

And you said something about how to charge the batteries. I've heard about a charger which i could change the V on my own, does it exist? Or is it possible to find a charger like http://letro.se/aspshop/shopfiles/shopartinfo_mer.ASP?ProdId=20035 for 14,8/15V?


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## beekeeper5 (Aug 30, 2011)

ahorton said:


> Personally I'd be going for a RC LiPo pack if you want an hour or more runtime.


 
I was also thinking of running my DIY light using an RC LIPO pack but they don't have protection for undercharge. Does your RC LIPO pack have protection?


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## Epsilon (Aug 30, 2011)

Simple question: have you seen an xm-l at night without a reflector? 

Because I seriously doubt that you would need more light.


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## ahorton (Aug 30, 2011)

Lots of good suggestions in this thread. I'll add another: 

Get a big chunk of aluminium or copper (it can be a solid or finned piece) and start sticking XM-Ls onto it. Power them up and see how much light and heat you are getting. This is the best way to get an intuitive feel for the heatsink and heat-exchanger requirements. Better to invest time with a quick and simple prototype than to rush into a final design.


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## cdrake261 (Aug 30, 2011)

Epsilon said:


> Simple question: have you seen an xm-l at night without a reflector?
> 
> Because I seriously doubt that you would need more light.



IIRC, xm-l's has a 125 degree spread...



ahorton said:


> Lots of good suggestions in this thread. I'll add another:
> 
> Get a big chunk of aluminium or copper (it can be a solid or finned piece) and start sticking XM-Ls onto it. Power them up and see how much light and heat you are getting. This is the best way to get an intuitive feel for the heatsink and heat-exchanger requirements. Better to invest time with a quick and simple prototype than to rush into a final design.


 
To run 6 xm-l's at 3amps will be impossible, you cannot cool it unless you have an extremely large heatsink....it's impractical. Techjunkie wasn't kidding when he made the "catch your hair on fire" comment


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## The_bad_Frag (Aug 30, 2011)

You want to have something like this on your head -> http://www.candlepowerforums.com/vb/showthread.php?320575-6-XML-flood-light-with-active-cooling 

I think the only way to have such a powerful headlamp is to build it with watercooling. You would also need to wear a backpack with build-in radiator, waterpump and battery pack on your back.


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## Epsilon (Aug 30, 2011)

cdrake261 said:


> IIRC, xm-l's has a 125 degree spread...



Which is great for his application .

BTW, 18650 batteries weigh 60grams each or something. So you know. The heatsink in your startpost will not be enough to cool 6 xm-ls T full throttle.


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## Challe_ (Aug 31, 2011)

For all of you who says it should be enough with 1000 lumen, take a look at http://ledx.se/ljustest/ and then "Lupine Betty". The specifications is set to 1850 lumen, and i want something stronger.

Thanks Epsilon for telling me the weight of a battery. But I think 125 degrees is a little bit too much, I have not planned more than max 35 degrees.

Ahorton: I don't have the oppurtunities to test it with real equipments. I hope that they know the spec. in the other thread The Bad Frag linked  Thanks for the tip anyway!

Anyone have any suggest about the rest of the questions? If you have a guide in a thread with good information, please link it!


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## MikeAusC (Aug 31, 2011)

Challe_ said:


> . . . . . I want a nice lamp which surprise everyone who see's it . . . .



Even if, as a first-timer, you can overcome the technical problems, you will end up being banned from using this light by your fellow runners, because your light would blind them.

I've just finished as Recovery Team on a 100km walk - anyone who used high-powered headlamps designed for cyclists caused painful glare and ruined nightvision to others.

I suggest you find other ways to impress people.


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## MikeAusC (Aug 31, 2011)

Challe_ said:


> . . . . Ahorton: I don't have the oppurtunities to test it with real equipments. . . . .



When a first-timer has this simplistic view of building high-powered LED lights, you know the project will end in tears !


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## ahorton (Aug 31, 2011)

Challe_ said:


> Ahorton: I don't have the oppurtunities to test it with real equipments. I hope that they know the spec. in the other thread The Bad Frag linked  Thanks for the tip anyway!
> 
> Anyone have any suggest about the rest of the questions? If you have a guide in a thread with good information, please link it!



What do you mean you 'don't have the oppurtunities to test it with real equipments'? Find a chunk of aluminiun or an old CPU cooler. Then stick some XM-Ls on it. Find a driver (look at the drivers listed in the electronics part of the forum) and hook it all up to your energy source.


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## ahorton (Sep 1, 2011)

... another thought of mine which might not be ignored by the OP:

Your real aim is not to make a useful sporting headlamp, but rather to 'impress' your friends who are used to 2000 lumen lights. So you'll probably need a lot more than 6000 lumens. I once made a 14,000 (emitter) lumen search light. It was very bright. It felt about twice as bright as a 2000 lumen search light with identical beam angle. The 14,000 lumen one couldn't really see much further (approx 400m) than the little one, you just saw everything better.

As stated earlier, I don't really think a 60W headlight is practical and I think you really need a 200W light to get the wow-factor you want. So maybe you can try a different approach. Instead of going for maximum flux, go for maximum intensity. Get a single XR-E or XP-C etc and a 75mm aspheric lens. Run it at 1.4A and you'll get a throw of around 500-600m. It'll be useless for orienteering but we established that this would be the case anyway.

Advantages:
Only 4-5W so heat and energy source are not a problem
all main parts can be bought for a total of about $25 from DX
You will be able to make it without much skill.
It will actually be unique.
Big 75mm glass lens will be lighter andf more compact than a 60W aluminium heat exchanger.


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## Challe_ (Sep 3, 2011)

ahorton said:


> What do you mean you 'don't have the oppurtunities to test it with real equipments'? Find a chunk of aluminiun or an old CPU cooler. Then stick some XM-Ls on it. Find a driver (look at the drivers listed in the electronics part of the forum) and hook it all up to your energy source.


 
I very simply thinking of the equipment he uses: http://www.youtube.com/watch?v=xOfFYOYQ4rg&feature=player_embedded But I will test this! Soon i will order some stuff for making a 3 emitters-headlamp and then I hope I know if it's possible to make a 6 emitters-headlamp  Just going to find a good driver and a charger (14,8V)!


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## The_bad_Frag (Sep 3, 2011)

This guy has 0 idea what he is doing. He overheats this XM-L really bad. Max runtime under that load are 3-5 sec until the star and led is already overheated. And he didnt got it to full power with his awful test setup.


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## ifor powell (Sep 4, 2011)

I have made some Night Orientearing head lamps (getting on for double figurs now) but nothing with xml for O although I do have a 4 XML bike light setup. Running will help with the cooling and I have reduces the weight of my lights over time. My curent bright light setup is a 7 xpg setup mounted on a big old Silva plastic headstrap I only use this for big events. For most small events I just use a 2xpg setup that comes in at only about 150g with batteries for an hour.

6 Xml is probobly overkill I would stick with just 3 or 4 and a Hipflex for the driver. You realy do want a multi level driver, you need to be able to turn it down before and after the run when there want be such a cooling effect and and you don'tt want to dazzel everyone. I find the hardest bit of construction is the headband and mounting settup. I have not been able to make anything any good personaly hence reusing old stuff.


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## plengqui (Sep 9, 2011)

I like your project.

For batteries you could buy the 4*18650 battery pack from DX. It has protection built in, and there is a compatible charger. 
http://www.dealextreme.com/p/4400ma...-with-pouch-for-sku-29489-30864-4-18650-32756
They give about 7.2 V each (max about 8V fully charged) and 4400 mAh. So two of those in series gives you your desired voltage.
Double that again, in parallell to give you your desired runtime. 
I think you will be able to run with that if it is on a harness on your back.

Now for the cooling issue: 
I think you need theory to get into the right ballpark. Heatsink specs often state a thermal resistance in degrees celsius per watt. Each XML puts out about 10W.
Then you also need to experiment. Your plan to start with 3 XML at first sounds great. Of course make sure to get good airflow through the fins of the heatsink.

Good luck and be sure to keep us posted on how it works out for you!


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## plengqui (Sep 9, 2011)

Here is some reading on cooling and heat management in LED applications:
http://www.qats.com/cpanel/UploadedPdf/Qpedia_0909_web.pdf
http://www.led-professional.com/downloads/LpR_13_468932.pdf

/cheers


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## CampingLED (Sep 9, 2011)

I built a triple XP-G R5 headlamp and in high mode I usually only keep it on for 3 to 5 minutes max. It gets quite hot. In med I can keep it on as long as I want to and it becomes warm, but not hot. In low it cools down from either high or med used before. Light output in med is more than enough for most applications. First light that I pack in when I go camping and also packed it in this morning for a weekend trip. Every time I use it my mates also want one. 6 x XM-L is overkill for a headlamp.
http://www.candlepowerforums.com/vb...-XP-G-R5-Tripple-headlamp-NOW-WITH-BEAM-SHOTS


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## Challe_ (Sep 10, 2011)

Plengqui, thanks for the suggestions and advices! I will keep it in mind! 

I still have some questions. Is it possible to charge a batterypack on 18,5V with http://www.dealextreme.com/p/hp-pa-1650-02hc-18-5v-65w-replacement-ac-power-supply-100-240v-32004 ? Do you have any suggest for a charger on 14,8V ? Dealextreme or somewhere else 

Is it possible to order this mounting part (and rubber-band)between the light and the head strap: http://www.dealextreme.com/p/t6-wat...te-led-bike-light-with-battery-pack-set-82510 ?

Do you have any suggestion about a lowweight, runningfriendly harness? (from dealextreme)

And the last question right now, is this a clicky switch: http://www.dealextreme.com/p/replac...fire-6p-c1-more-25-5mm-diameter-threads-14024 ?

Thanks!


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## HarryN (Sep 10, 2011)

Let's assume you want to go forward, just for the fun of it. First - skip the deal extreme stuff and buy some decent drivers. If you don't have the money - then skip drivers and use a resistor type setup with the LEDs in series. It is cheaper, more reliable, and instantly available.

Next - for heat spreading, what you need will be sort of like a metal hard hat. This will spread out the heat, and the spacing will keep it a little bit away from your head. This is important, as the human body can only deal with 15-20 watts of heat extra on a normal day, perhaps as much as 30 watts on a really cold day and you are under dressed for the cold air. Finding the metal hard hat is key to your project success. With it, it all might work. Without it - don't bother.

If you are playing with Li type cells, packs and chargers, don't go cheap or you really will end up in flames. If the light is just over the top bright - well that can be dealt with. If it gets too warm - you will figure it out. If you die from not properly managing a Lipo pack - that is more serious.


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## minorearth (Sep 11, 2011)

Hi,

i use a 7 x xpg r5 as headlight for nightruns. works extremely well.

http://www.candlepowerforums.com/vb/showthread.php?311505-selfbuild-headlamp-7-x-cree-xpg-r5

and here are some photos:

















the weight of 184g on my head is okay, it's 20g more then a lupine betty for example. 

okay guys, if you realized this project, in interesting in this project and i hope you made a lot of photos to share with us.......

christian


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## Challe_ (Sep 12, 2011)

HarryN: What do you mean with metal hard hat? I've google'd it without any results. And you're saying that the body can only handle 20W a normal day, but that can't count if I don't have a directly contact to my head, can it?

minorearth: Really nice lamp you have there! I've sent a message to you, but I'm not sure if you've got it.. please take a look!


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## HarryN (Sep 12, 2011)

Hi, I am not sure where to find a metallic hard hat, but that is conceptually what you need for that much power. A regular hard hat is designed to keep the shell of the helmet away from the head. The only thing touching your head in a hard hat are the straps.

It might be possible to find a WWII steel helmet and use that, or perhaps you can fashion something from an Al cooking bowl.

Think of your body like a liquid cooling system. It can move a fair amount of heat around, but in the end, the most it can dissipate is approximately the amount of sweat you can evaporate while staying within the body's control temperature range. My experience, is that this is around 15, maybe 20 watts continuous max, at least for me. If you go with a lot more power than this into your body, you risk local over heating and the light will feel very hot. Consider that many people with single LED XML lights (about 10 - 12 watts into the hand) already talk about them getting pretty warm. I can tell you for sure that 15 watt LED lights feel real warm real fast. I don't know anyone that can withstand 50 watts of heat going into their body for very long - maybe if they are sitting in a swimming pool it will work.

The only way I can think of to avoid this heat going into your body, is to mount the LEDs on a large surface area object (like a metal hat) and wear it in a way that it does not directly contact your body. I suppose a strong fan could work as well, but I don't think running speed is going to really matter that much.



Challe_ said:


> HarryN: What do you mean with metal hard hat? I've google'd it without any results. And you're saying that the body can only handle 20W a normal day, but that can't count if I don't have a directly contact to my head, can it?
> 
> minorearth: Really nice lamp you have there! I've sent a message to you, but I'm not sure if you've got it.. please take a look!


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## ahorton (Sep 12, 2011)

Instead of a metal helmet, I have often considered getting 3 or 5 strips of aluminium. Say 1-2mm thick and 20-50mm wide. Then bend them around the sides and top of your head. Cut them to the right length and rivet them together. Voila! you have most of a metal helmet. Make sure it sits about 10mm off your head on every side and line the inside with a high-density foam.


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## cdrake261 (Sep 12, 2011)

ahorton said:


> Instead of a metal helmet, I have often considered getting 3 or 5 strips of aluminium. Say 1-2mm thick and 20-50mm wide. Then bend them around the sides and top of your head. Cut them to the right length and rivet them together. Voila! you have most of a metal helmet. Make sure it sits about 10mm off your head on every side and line the inside with a high-density foam.


 
Why don't you get a bicycle helmet and do that?


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