My Homemade headlamp

[ahorton]

I actually made this months ago but thought I might post it up since I learnt everything from this forum. I've made about 5 different headlamps but this is my favourite so I'll show it.

It's going to become obsolete soon anyway since I have requests from more than 20 friends to make one for them which means I'll be getting them CNC made. For a homemade headlamp though, I can't imagine it being much better than this for my use. It could have been cheaper though since I used to buy from Cutter and am now a DX convert. Hence the Buckpuck in this version while my future lights will be AMC7135 driven.

The strap, battery pack and front mount are from a 10 year old Petzl Zoom.

The aluminium head is a bit of scrap c-section and the heatsink from this.

Mass without batteries is 196g.

The waterproofed toggle switch flicks between the 2 modes.

High: R2 driven at 1A by a buckpuck and focused by a 30mm Aspheric. The lens is held slightly closer than the focal length because I like to have the widest beam possible at 100m throw.

Low: 4*5mm LEDs in 2s2p getting on average 30mA each (just resistored).

Battery pack is 7.4V and I have two types as shown. The one on the right is made of 2 DX 18650 2500mAh protected cells.

This closeup photo isn't great but it shows my LED mounting. I actually soldered it to brass rather than copper. Copper conducts heat better, but I liked brass being stiff enough that you can use stainless steel bolts to put a huge amount of pressure on the contact surface. You notice it when much more of the interface material (Arctic Silver in this case) gets squeezed out.


The little lip at the bottom solves a problem from an earlier design in which a tiny bit of light from the 5mm LEDs reflected off the user's glasses and drove them insane. I didn't think about this at first since I don't wear glasses but my dad got back from a 24 hour bush race and made the suggestion.

 

[NightTime]

Very nice work ahorton! :thumbsup:

With this heatsink, you dont have to worry about overheating problem! Lot's of great ideas in this headlamp. I did make a headlamp of mine a few months ago with a heavy 6xAA battery pack. I wanted to use my L1D head on it. The whole thing wasn't completly done when Fenix came up with their headband. I bought it instead.

But knowing you were making one ... ;)

The runtime must be amazing with 18650s. Ever tested?

Cheers

 

[garilla]

I know that headlamp is small, but for some reason each time I look at it, it appears to be gigantic, can you put a pic up with it on someones head to get a good idea of it's size? Looks good though, any night shots ?? I am investigating aspherics myself and like what I see.

 

[ahorton]

The runtime is about what you'd expect. 4.5 hours on high and it'll start to dim but unless you have a DMM attached you won't notice it 'till after 5 hours. It's hopeless by 6 hours but the 18650 protection circuit still hasn't cut in.

On low it's dimming right from the start of course. I've set it going for 50 hours and the light is still very useable by the end of that.

That is more than enough for a 24 hour race with 14 hours of dark. At the end of some of these events I've checked the cells and they are usually at 3.7-3.9V each so they have plenty of charge left.

I also have lights with half the capacity and they can last a whole night but I'm willing to carry an extra 50g and use the high beam more often.

 

[NightTime]

The runtime is about what you'd expect. 4.5 hours on high and it'll start to dim but unless you have a DMM attached you won't notice it 'till after 5 hours. It's hopeless by 6 hours but the 18650 protection circuit still hasn't cut in.

4.5 hours is amazing for high output! Especially when you consider you can keep it on high without wondering about overheating issue. Great job.

Any idea about lumens? Just curious 'bout it. I dont really care the exact number, but if you do a ceiling bounce test can you compare it to let's say High mode of an L2D Q5. This is just an example. I don't know what you've got in your collection.

Cheers!

 

[Frozen]

this[/URL].

I have very similar idea about it!:twothumbs

This one will be on handlebar of my mtb bike, but in future I'll go in serial build and one will have mount for helmet.
I coupled 2 heads together. One for leds, second for driver, cable connector and switch.
It's not finished, but works on table. Somewhat overheating on max 4xR2 - but if I give it a little breeze from 5 cm computer fan, it works perfectly. I am waiting for waterproof connector and switch, and then will have to make mount system.

 

[ahorton]

Any idea about lumens? Just curious 'bout it. I dont really care the exact number, but if you do a ceiling bounce test can you compare it to let's say High mode of an L2D Q5. This is just an example. I don't know what you've got in your collection.
Cheers!

R2 at 1A should be about 250 lm but my guess is about 200 are going where I want them. Just a guess.

These photos are pretty bad but you get the idea. I just walked out into the street and took some pics of my shed and a tree.

Shed control

30m from shed

70m from shed

Tree control

90m from tree, 45m from house.
I think this one shows the amount of useful spill which is not what I expected using an aspheric. I like it.

My ceiling

You'll notice a massive ring in the beamshots. My lens is held in by a perfect friction fit so the flat 1mm lip around the edge (which you are meant to use for mounting) makes the ring. This has never worried me.





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[NightTime]

I'm quite impressed by your headlamp's output!

 

[Moddoo]

Nice work.
good find on the heatsink.