Derailled

My light design uses a 50mm lamp, aluminium tubing, nylon end caps, total cost for building one of these lights with a battery and charger is less than $120.



Shopping list:
- 1x 12V Rechargeable Battery + Charger (Run time depends on Ah of battery, 7Ah = ~2h20m.)
- 1x 50mm 24deg 12V 35W IRC Halogen Dichroic Lamp
- 1x Lamp holder for above
- 2m 10A rated cable (Tru-rip or similar)
- 1x 10A 12V SPST (or SPDT) switch
- Assorted crimp lugs, joiners (or use solder)
- 50mm Round Aluminum Tube (thinnest wall, only sold by the metre so may pay to group buy this purchase.)
- 1x #8735 51mm Nylon End Cap
- 1x #4761 50mm Nylon Plug

These are the suppliers I used for all the parts listed above:

Rexel Christchurch: Lamps, Holders, Battery, Charger & Cable.
Dick Smith Electronics: Switch & Crimping gear.
Para Rubber: Nylon End Caps.
Mico Metals: Aluminium Tube.

Laid out in the picture below are the majority of the parts you need.

Start out by cutting yourself a 100mm length of your aluminium tube with a hacksaw.

For heat dissipation I drilled four 6mm holes in the tube, two in each side.



Take your two end caps, the one on the left is the rear end cap and the one on the right is for the front.

You need to make a 45mm hole in the front end cap, I used a hole saw on a battery drill for this, but you could use a medium sized drill bit and make a number of holes, clean it up with a craft knife and file.

Depending on your switch and cable you may need to make different sized holes in the rear end cap, mine required a 6mm hole for the cable and a 20mm hole for the switch, I used a 20mm spade bit for the switch and a 6mm drill bit for the cable.



To make the front end cap easier to get on, I cut it down to about 20mm as you can see from the before and after pictures.



I've used crimp lugs to wire up the light, you can solder if you like.

Tie a knot in the cable going into the light so it won't be pulled out, run one power cable to the switch, the other to the lamp holder, then run the other wire from the lamp holder to the switch. Leave enough length so when inserting the lamp you will be able to pull the holder out the front of the tube.

Check that the switch powers on the light as expected before continuing.



From this next picture you can see how your lights should look when assembled.

Firstly put the rear end cap in, this takes a fair amount of force, push it and the tube against a bench or table top, once it's in it ain't going anywhere!.

Pull the lamp holder out far enough to put the lamp in then rest the lamp against the edge of the tube, now carefully put the front end cap on, work it slowly from left to right up against the edge of a bench, do this until the lamp is no longer able to rattle about.



Hopefully by now your light should look similar to this, I simply zip tie mine to the top of my helmet using the vents, or you could use a velcro strap or similar.

I have put a connector on the power lead to the lights to make life easier, they're commonly used on Tamiya Radio Control car batteries and available at most hobby or electronics stores.

Stay tuned for a budget LED version, hope to get something going in a month or two

I look forward to seeing that version.

I have looked into building LED night lights myself... but to be honest it all looked pretty complicated and I ended up buying a Nightlightning Iblaast instead

If you find a simple and not too expensive build that works I am sure you will have plenty of people assembling them!!

That is the goal, you can't escape the cost of the batteries tho', its a real sticking point, at least with the LEDs you get a bit more runtime... I have a few neat ideas for cheap housings people can make with very basic tools, will just have to settle on what bulb combination to run

I loved the halogen that I built hated the weight of it though. In the process of retro fitting LEDs to a Percy halogen housing.

Hey JB I can do a little write up on my LED lights if you want. Built 3 now and currently making another to sell which I should get done soon.

Dude, a writeup would be awesome!!

Keen to see what you've done, how do they compare to the halogen's light output?

Datsanes ones are pretty sweet. I took them for a spin round the paddock at Pukete and managed not to crash into anything which is saying something.

What he said!

I am gonna try some fancy batteries my bro has lying around for his model helicopters, well light and mega grunty, just try them on my hooligans first!

Got the Triple LED light going friday night finally got to have a ride with it tonight. Sadly I had to use a 7Ah brick which wasn't a problem till I came off and landed on it

Light was great (Kind of expected it to be) but had it pointing way to low like 1.5 - 2metres in front of my wheel. And I wouldn't mind trying 10deg lenses rather then the 15's I have. Not an issue with heat, then I didn't think there would be in the bench test it only got to 41*C after 10minutes sitting with ambient air temp 26*C

I'll do a step by step with photos over the next day or so. And hopefully a beam shot or two.
Step one is easy buy one of Percy Pigs halogen housings

Mmmm I reckon 10-12 deg is mint for night riding, very keen to see some pics au!!

Noice one!

I must make some more of those housings, and soon like, so people can make lights before night riding season is apon us.
Anyone want one now?

The housing was made by Percy some years back ran as halogen got sick of the battery so this is how I changed it to LEDs, the way that I did the swap will work with any housing that takes a 50mm halogen lamp. As a side note IMHO unless it’s Aluminium it’s not going to be as effective a swap something like plastic not being able to dissapte the heat and would need to use a driver them at a lower current value or spend a little bit of effort in heat sinking. I have the driver in the rear part of the light housing which some may do or may not (opting for a remote switch housed with a driver inline of the cable.

First off remove halogen lamp, I’ve managed to recycle the front and rear caps, power cable and off/on switch to reuse most others should be able to do this also.

Second step: The heat sink/LED mount
I have bits of copper lying about from my time building industrial switch boards. Alu would be lighter, but wont to my understanding absorb the heat as effectively as the copper again IMO.
To make things simple I used a hole saw to produce an over sized piece which I drilled and tapped to M8 then threaded in an M8 bolt (wow really) so to hold it in the jaws of the lathe chuck. Then turned the copper down to fit snugly in the housing. If you don’t have a lathe the drill, hacksaw and file method will work just will take more time and my not produce that same clean fit.
Housing with heat sink

Step three: Assembly Heat sink
There are a few parts to the assembly process, start by dummy fitting the heat sink in the housing. My LEDs plus lenses came to a height of 14mm so pushed the heat sink in 13.5mm or there abouts. Before you get it to the right depth put heat sink paste (the stuff used on PC CPUs) on the housing where the heat sink will sit. Then I drilled and tapped for M3 screw or for a self tapping screw. Really the screws there for safety if the fits tight enough it shouldn’t be needed.
Heat sink inside housing with LEDs in place and one lens.

Assembly LEDs
I filed off the small casting/joining marks on the edges of the LED mount, just to make them sit better.
I’m connecting the LED’s in series so I tinned a – and + on each LED. Using a short wire link to join the LEDs at a – to +, then finally the leads that go to the driver.
Smear heat sink paste on the back of the LEDs, place them into housing. Fit the lenses on my light I didn’t need to use holders when the end cap and cover are fitted it holds the lenses tightly against the LEDs. It’s also the same reason I didn’t require fixing the LEDs to the heat sink.
LEDs in place with leads and connections.

Assembly Driver, switch etc…
It’s a no brainer really Drivers normally come with a diagram on how to wire them up either 4 or 6 wires to connect. The Switch isolates the battery pack the same as on my halogen. The driver I used can be used with an external resistor to lower the current output of the driver making the LEDs dimmer. I’m using a 10k Ohm trim pot to very the output. Cant do it while riding but easy enough to remove the rear cap to adjust the trim pot for different riding situation ie. Commute, multi lap XC race or trail riding.
Driver, trim pot and leads that go the the battery and switch. Still with the halogen light fitting, I'll change that at some point :paranoid:

I think that’s about it. I’m using a 12V SLA for now, until I at least sort a decent holder for the cells. And haven’t got a beam shot yet. Hoping to get a few other lights to compare it against.

And like every one else I just cable tie it to my helmet for riding.

Nice one!!

as long as your not a complete meat head its not all that hard. Learning to solder cleanly would be the only thing some might have trouble with.

So how much did all this technology cost, and where did you source the LED's and stuff?

All up I'd say about $200. Cheaper then alot of places sell just the light
My halogen was $100 ish

Deal extreme for the LEDs, all batteries for strangly enough batteries and chargers and LED supply for Drivers and Optics.
Next to the batteries (Nmih) the Drivers and Optics are the most expensive item. LEDs are alot less then you think when you price the rest of the items.

Hoping to get some beam shots Wednesday or Thursday this week.

Coolies!

Beam shots would be kewl.

Dude thats awesome, just the kinda thing I was thinking of!!

Making a plugin halogen replacement unit would be a nice little earner I reckon

Would be I had though about trying it, if you could get the heat issues sorted easily enough. The trouble I found is the ID of the housing people are using can very by some 5mm and thats with an OD of 51mm

That is all mine is really.


I got hold of some large diameter tube with an ID of 63mm (or so). I'm guessing that I could get 5 in to it or making it oval and having 3 or 4. Mostly would make it slightly lower in profile. Need to get a press of some sort as I don't think the vice will cut it.

My light also works rather well for spotlighting little critters