DIY MTB light

[Pitto]

Hi all, i have been lurking in the background for a few weeks looking at everyones projects and im impressed with the quality of the work. i am looking at building my own led light using cree and a few other parts from cutters mounted in a head from an old MAGlite.

i was looking at a 50mm tri lens arrangement as it seems to be around the perfect size.
what are peolpes oppinions on these lenses??

i was also looking at direct driving the 3 crees, and using 9.6 nicads. i have a makita 15min charger so i figure using the slim 9.6v 2.4ah batterys would do the trick.

this will be a switch on-switch off system as i dont need to have it dimmable.
any feedback would be great.

Thanks

 

[AndyTiedye]

A little hard to tell much about the lenses from the picture.
What kind of lenses are they?

Other bike light threads on CPF can be found here

 

[Pitto]

lens details can be found here
http://cutter.com.au/proddetail.php?prod=cut561

thanks for the reply, i have been thru a lot of those threads already. but i have not found anyone using the tri lens array, rather single optics grouped [ledil]

i have a LED light that i bough from a guy locally, it uses the tri lens assembly in the spot option, and it seems to work great. i payed a bit for it and would like another one, but i figure i have basic electronics skills, so i will make my next one. the one i have now also runs luxeons, so i am keen to see how the cree's work out [seeing as they are the flavour of the month ]

 

[greenLED]

Pitto, welcome to CPF. Try searching for "tri-lux" (or trilux) and/or posts by modamag and icarus about it in the homemade and modified section.

 

[Tidra]

I was thinking of using one of thous for SSC P4,...


http://www.ledil.fi/pages/3106/

 

[Pitto]

thanks lads, shall go a hunting........

G

 

[chris_m]

Unfortunately I think that that lens is designed for the older model XLamp, not the XR-E, as Khatod now do a new model of that lens http://www.khatod.com/k52_triple_xlamp.htm - note the different suffix (last time I looked the Khatod site showed the TL lens and also a different XR-E specific one, so it seems this is a very recent update). That newer lens looks like a very nice triple solution.

Khatod do also do a triple lens for the P3 series of LEDs - I already have some of these, and I'm hoping that the P4 series is close enough that it will plug and play - will know in a few days when I get my LEDs.

 

[FirstDsent]

Pitto,

50mm optics usualy fit perfectly in Mag heads. Modamag makes a PXR heat sink for MagLite based flashlights that accomodates 3 Cree XR-Es. A Mag head, and a shortened body mounted to your bars would rock. You don't need a switch or a battery tube, so you just need a body long enough for the heat sink, electronics, and power cord. Several of the Mag modders can machine tailcap threads in a shortened body. I think it would just need to be long enough for both sets of threads (head and tailcap).

Bernie

 

[Pitto]

Pitto,

50mm optics usualy fit perfectly in Mag heads. Modamag makes a PXR heat sink for MagLite based flashlights that accomodates 3 Cree XR-Es. A Mag head, and a shortened body mounted to your bars would rock. You don't need a switch or a battery tube, so you just need a body long enough for the heat sink, electronics, and power cord. Several of the Mag modders can machine tailcap threads in a shortened body. I think it would just need to be long enough for both sets of threads (head and tailcap).

Bernie

Yeah, i have a cut down mag D already that was made for a halogen mr16 bulb, i am going to rework the unit, hence looking into a 50mm trilux lens assembly.

i am going thru the process of working out components now. i will post up my list for review soon.

 

[Pitto]

Ok, heres what have got organized.

after looking at this forum for a few months now, i have just ordered 2x cree dropin modules off ebay that should be here in a few days time. I am going to use those and make a Nightrider style housing for them as per a post i have seen around here. [ https://www.candlepowerforums.com/threads/162245 ]

if i am running these dropins with 9.6v, should i wire them up in series? and if i were to go for a LI-on 3.4v battery, would i wire it up in parellel?

one more question, is there any issues with discharging a LIon battery? do i need a protection circuit for it or is this only the case when charging them?

Thanks

G


FRONT

BACK

DROPIN MODULE

BATTERY - OPTION 1 - MAKITA

BATTERY - OPTION 2 - HELMET MOUNT

 

[Pitto]

ive reworked the design a bit.

this will be the one i build. i will cut some 2mm glass for lenses to stop dust & crap getting in.

G

 

[Timson]

Pitto,

Nice illustrations.....Have you found a supplier for that size of heatsink, shown on the back of your housings?

It's exactly what I've been on the lookout for.


Tim.

 

[yellow]

thats much questions :thinking:
Sure You want to do this?

* if 9.x volt battery: inserts parallel
* if li-ion batt: inserts parallel
--> in short: consider each as being a single light not possible to be wired in series with another
* how'd You plan to mount the glass?
* can You do the metal work?
* What will be the cost?
* why not use a Maghead? (thats 12,-- at Your place)
* Li-Ions without protection get damaged when discharged too much (= under 2.5 Volts). There are dirvers here, that might squeeze them out too much. No clue on the one used here but they might go into direct drive with reduced output and wont hurt them (thats a guess, nothing more)

that heatsink is too much and sitting at the wrong place.
Those inserts should be press fittet into some metal at the middle part, thats where the inside heatsink sits. And this wider metal should directly be press fit into the metal housing.
Also You do have more losses, as every Led uses its onw circuit.

imho much better, easier and cheaper were to use a maghead.
Get a round aluminium plate, cut three holes in it for the three inserts You use and press them in, or - better-but-more-expensive - make a traditional multiemittersetup with the one circuit driving the three emitters wired in series.

 

[yellow]

just read the linked tread You got Your idea from,
read my comments there.
at least set the two beams not parallel. A few degrees offset and You end up with an oval beam with a very bright spot in middle and some light left and right and all the spill around.

but imho this way is totally wrong and has no chance to give a better light than the Maghead version
AND
is more expensive, time consuming and in the end less good looking than the ready made head used for the housing.
only concern is that the wide reflectors used here will have to be cut to fit into.

 

[Pitto]

ok, cool, points noted. :thumbsup:

Lexan will be machined and held inplace with silicon.

Dropin modules will be held in place with a heat transfer style silicon or arctic alumina to ensure heat transfer from the dropin gets passed on to the body of the light.

Heat Sinks will be what ever i can get my hands on and cut down to size.

I like the idea of the light slightly offset for an oval shape pattern

G

 

[lexina]

Pitto,

50mm optics usualy fit perfectly in Mag heads. Modamag makes a PXR heat sink for MagLite based flashlights that accomodates 3 Cree XR-Es. A Mag head, and a shortened body mounted to your bars would rock. You don't need a switch or a battery tube, so you just need a body long enough for the heat sink, electronics, and power cord. Several of the Mag modders can machine tailcap threads in a shortened body. I think it would just need to be long enough for both sets of threads (head and tailcap).

Bernie

That's exactly what I have done here :-




see this thread:-

https://www.candlepowerforums.com/posts/2061377#post2061377

The short tubes are left-overs from projects where Mags are cut to take a tail-switch. there are no threads at the tail-end so I used a rubber stopper to seal it up (saves on a tail-cap!).


I also noticed that DX now sells a tri-led reflector which looks tailored for the crees:-

http://www.dealextreme.com/details.dx/sku.4630

 

[Szemhazai]

If you want to use DropIn modules you will have to keep in mind one more thing there is almost no thermal connection between the square case and the module – at the end you have the spring only :

The best way to deal with that will be to drill the case from the square rood - then there will be no need to use additional radiator. In other case using additional glas cover at 900+ mA you will simply bake the leds.

 

[Pitto]

If you want to use DropIn modules you will have to keep in mind one more thing there is almost no thermal connection between the square case and the module – at the end you have the spring only :

The best way to deal with that will be to drill the case from the square rood - then there will be no need to use additional radiator. In other case using additional glas cover at 900+ mA you will simply bake the leds.

i was looking at using some arctic alumina or selleys metal based "kneedit" to form a connection between the dropin and the housing.

G

 

[Pitto]

drop ins arrived today. :thumbsup:

now to start the buildup process.

G

 

[Led_Blind]

You will laugh at my budding bike light.

I used old steel server HDD chassy and cut it to fit 4 crees and 4 of those square optics. It will run with a shark driver from a 12v source.

Before it gets fully assembled i am trying to figure how to create a low voltage warning led to notify when cell voltage is 9v or lower. anyone got ideas on that one?