I’ve been tinkering in my shed and come up with an Exposure Joystick Maxx killer for a third of the price. It’s a great compliment to my Nightlightning iBlaast LED lights. Here’s a summary (with more photos on Flickr)…
If like me you enjoy a bit of tinkering then have a stab at this and save yourself a small fortune. This light uses the most powerful small LED currently in production (240 lumens) and is quite easy and cheap to make at approx £45 plus batteries (less if you nick them out of you child’s favourite toy!).
OK, it won’t have the finesse of the Exposure kit as it has a separate battery, but looks just as good and performs better than the Joystick Maxx at a fraction of the cost. Also, how cool is it to say you’ve made something this effective yourself?
There’s no reason why you can’t bar-mount this setup or even make 2 and have one on your helmet and one on the bars. Battery power/life and mounting will be your main considerations.
First, an overview
The main thing to worry about with LED’s is heat and with 1000mA, the diode gets hot. Hence the design of the light unit – the aluminium design radiates the heat away very effectively. When riding, my light unit is barely warm to the touch but soon heats up when I stop so I’d recommend turning it off if you don’t expect to get moving again within a few minutes. But its long enough to leave on while you wash the bike down and very handy when doing so in the dark!
The lens specified gives a superb and far-reaching spot beam with a reasonable amount of peripheral lighting.
The constant current converter is necessary when powering LED’s – regardless of the voltage input it delivers a constant 1 amp to the bulb and ensures a consistent level of brightness until the battery goes flat, rather than a gradual dimming or yellowing such as you get with halogens as the battery drops off.
You can also opt for the 700ma version, which will improve burn time but at the expense of brightness.
My set up gives me nearly 3 hours at full-power 240 lumens so more than enough for the average night ride. I’m using a li-ion battery that I purchased for my prototype version but AA’s will be more convenient and just as effective. 2700mAh AA’s will give you over 2.5 hours of burn time.
The input voltage can be anything from 4.8 to 32 volts, the important factor is the power (or amperage) – in simple terms, divide the amperage (in mAh) of your battery by 1000 (the output of the converter) to give you your burn time.
The thermal epoxy is important as it helps ensure the heat is transferred efficiently to the light unit and remains strong when the temperature rises.
I’m not going to write a full instruction book on this, so commonsense is required but please contact me if you have any queries or want me to email you the drawing to get the light body machined.
|Seoul P4 Z-LED (240 lumens)||www.led-tech.de|
|1000mA Buckpuck Constant Current Converter||www.ultraleds.co.uk|
|Luxeon Collimator Lense and Holder LXHL-NX05||www.ultraleds.co.uk|
|Exposure Joystick Helmet Mount||www.chainreactioncycles.co.uk|
|4 x 2700mAh Rechargeable AA batteries||Various|
|Connectors for power lead||Various|
|Thermal epoxy resin||www.led-tech.de|
|Suitable flex (I used the 2 core wire from an old mobile phone charger)||Various|
|Inline switch, preferably waterproof||Various|
First off, you need to get yourself a friendly machinist to knock-up the light unit from aluminium. Expect to pay around £15-£25 depending on how well you know them!
You can get the hole for the wire drilled wherever you want but going in from the side is best in order that the wires can enter the casing adjacent to the small semi-circular cutouts in the LED base.
A few tips
- When you solder wires, make sure you tin (lightly solder) each one first before attempting to solder them together – it really helps
- After soldering the joints on the wires, seal them with heatshrink and then wrap insulating tape around them. Soldered joints are not strong and this helps to keep them firm and supported and free from movement-induced stress
- When the wires are soldered to the LED, try to keep them as flush as possible or they’ll prevent the lens holder sitting down far enough on the LED. I ended up shaving plastic off part of the bottom of the lense holder with a Stanley knife where it butts up against these joints
- The Exposure helmet mount I’ve used is good but you may think of a better one – its up to you. If you do opt for this one, you’ll need to ‘modify’ (ie shave plastic off it with a knife) in order for it to fit the recess on the light unit snugly
- Put the heatshrink over the wires first before soldering them!!
That’s it, the rest is up to you. May not go easy first time round – soldering takes practice. Just take your time and go enjoy your creation!
View the document for the light body here (do right click/save as to download it)
Disclaimer – I am no electrical whizzo so I may not be 100% factually correct in what I say but it works for me and will for you too!