Thought I'd update my progress with home made lamps....  Previous post here: http://ukcaving.com/board/index.php?topic=6444.msg88301#msg88301

I've found some useful online resources for design checking your lamp design here and here    Anyhow my new lamp is a turned aluminium housing (done by myself which is why it's a bit wonkey) that has then been anodised (paid ?15 for two lamp casings to be done).  The design has a separate backplate so that I can fit in two driver boards and uses an Oldham spade bracket.  Each of the LEDs is driven separately and controlled by the two switches on the side of the light.  The design uses 2 Cree XM-L LEDs  which each driven by a Taskled H6Flex driver at a maximum of 2.8A, this gives a combined output of (an estimated) 1800 lumens - far more than you'll ever need and enough to loose all your caving friends but it is an immense amount of fun! The nature of the drive boards means that the max drive current could be set lower so as to maximise battery life.  One LED is a diffuse beam and the other has a Carclo optic to give a beam - not as tight as a Scurion beam and I don't know how it compares to a Little Monkey light.

Sorry for picture quality:





Battery wise I use the DealExtreme Trustfire 18650 protected Li ion batteries wired into a 7.4v pack.  These then use a waterproof connector again from DX and are encapsulated in Plastidip.  I also add a polyswitch to limit the maximum current out of the pack and leave the over charge/discharge protection to the internal cell circuitry.

All in I think this lamp has cost ?100-110.  Only disadvantage I can see so far is that the headset weighs 250gr by itself.

Looks good. 

Is the heat sink enough to leave the two LEDs running at full power whilst in a cave without the thermo-protection of the board kicking in?

Reckon you could probably lose the carbide bracket now.

Where did you get the switches from?

That looks like a nice lamp, those switches look like they are protected by screw on rubber boots, and they make the seal against the body ? I happen to use them for one of my products, Farnell code 108-2519
, unless you get them from somewhere else.

Probably is time to loose the carbide bracket!

Switches and boots came from RS, part numbers 119-3692 and 614-6332.

I have had the lamp running at full whack in the house (with the central heating on!) and not had the thermal protection kick in (set at the board sensor being 50C) - comparing to a Scurion this weekend I have got a bit more surface area for cooling.

Biffa, is that code right for the switch? RS website says that is a momentary switch.

Quick question, what material did you use for the faceplate/lens, and how scratch resistant is it?

stu said:

Biffa, is that code right for the switch? RS website says that is a momentary switch.

Click to expand...

My understanding of momentary is that contact is only made whilst you're pushing the switch (i.e. it doesn't latch) and this is what is required as a control switch for the TaskLED driver boards.  Definitely the code for the switch that's in the light.

Joe.Bones said:

Quick question, what material did you use for the faceplate/lens, and how scratch resistant is it?

Click to expand...

Material is 5mm polycarbonate sheet.  I have wondered about trying to get some coated polycarbonate to resist scratches better, but the same material on the lamp I have linked to above lasted almost 4 years without scratching that impaired the function of the light, that I decided it wasn't worth worrying about.

The lens is a separate unit from Carclo optics (code 10003), the "optiselect" on Carclo's website recommends it as suitable for the XM-L LEDs

biffa said:

stu said:

Biffa, is that code right for the switch? RS website says that is a momentary switch.

Click to expand...

My understanding of momentary is that contact is only made whilst you're pushing the switch (i.e. it doesn't latch) and this is what is required as a control switch for the TaskLED driver boards.  Definitely the code for the switch that's in the light.

Click to expand...

Understood. Clever things those TaskLED drivers then.