Double XML

Hi all.

I have made a smaller light to my usual (7 up xpg) and went for a double XML.

The prototype light pictured below was made with a hipflex driver with a maximum drive current of 2.8A using the 14.8v packs I had in stock but the next version will use a Lflex driver with a 7.4v pack

The round driver housing on the end has a stat led fitted to give some warning when the battery is getting low and I am still tossing up making it from carbon fibre for something different. I made the driver housing removable to give the option of mounting the driver away from the light as a puck which would be handy for a helmet light. If I use the Lflex driver then this would work well as the driver will not need to dissipate away as much heat as the input voltage is much closer to the output voltage.

The optics I used are the Ledil CRS square optics designed for XR-E leds. The current light uses a spot and an oval optic with the oval beam parallel to the ground to give width without the top and bottom flood. I'll post some beamshots later.

The light has a remote switch which can be mounted on the bar beside your grip or a longer one which can be attached to the strap of you camelpack or the side of the helmet. When used as a helmet option I usually mount the stat led in the switch so it can be easily seen as obviously you can't see the housing once on your head.

Weight wise at present it sits around the 160g mark but I would like to shave a bit more off without compromising the thermal performance.

As for output well the 7 up still out performs any light I have built but this little twin xml is very impressive. The 7 up draws 2.2 amps on hight were as the twin xml is around 1.2 amps when driven @ 2800mA.

Here's a few photo's. Note, ignore the bluetac handlebar mount, it was just for the photo

Glad to see your post again here, but lack of a lot of details than on MTBR.

Good to be back. What would you like to know?

More about your new mill. I always read your posts on MTBR.

Hi brad72.
Really nice looking light and I suspect it looks good on the road as well.
Beam shots?
I'll keep my eyes open when I'm out and about early in the AM in case I see something that looks like this - so if you find that an old guy with (ugly) custom lights is trying to attract your attention it's probably me (Assuming you live somewhere near me).
I'd like to know the identity of your power plug and where you purchased it.
Thanks.

thanks for the compliment. I mostly use the lights in the bush but they do an excellent job on the road. I just have to switch to low beam when cars approach otherwise I blind them. That's the advantage of having the selector switch next the handlebar grip or on the brake hood for a road bike

Beam shots are coming. I've got the flu so not keen to stand out in the Toowoomba 5º cold wind.

As for the connectos they are from RS asutralia , see this link and look for the M8 stuff http://australia.rs-online.com/web/search/searchBrowseAction.html?method=retrieveTfg&Ns=stockPolicy_au|1||new_au|1&Ne=4294581771&Nr=AND%28avl%3aau%2csearchDiscon_au%3aN%29&N=4294835115+4294597538+4294581598&multiselectParam=4294835115%204294597538&selectAttribute=4POS%20Circular#breadCrumb

Not the cheapest things in the world when compared to a cable gland or strain relief gland but they do look nice.

Too bad about the flu and I know what Toowoomba is like this time of year.
I'm on the eastern ouutskirts of Brisbane so you probably won't have me chasing you after all!
Do you know if there are any other keen DIY bike light builders from this region on CPF (or any other bike sites you might belong to)...if so a show and tell meeting might be a good idea.
My latest ugly MTB creation is at:
http://www.candlepowerforums.com/vb...ter-in-Australia-...-Time-to-build-new-lights!
Not a very good idea of the output with that photo. In real life it looks much brighter with longer throw. Excellent for off road use.
Thanks for the RS link - I have an account with them and have ordered a selection ($$$)!
Cheers.

I shaved some weight off the light today by machining the heatsink grooves deeper and thinning down the side walls. I'll find out just how much tomorrow when i go to work.

Tonight I tested the CRS optics again and thought it would be a good idea to try some Regina reflectors. After a bit of trimming I found the best position over the xml led so that I get a smooth spot with no dark areas in the beam. All I can so is wow. The light output at @ 2800mA is amazing with a nice bright spot but usable spill around the sides. As a helmet or bar lamp this combination will be excellent. I'll post some beam shots tomorrow night.

The challenge now will be to make housing small enough to dissipate the heat away efficiently in summer whilst keeping he weight to a minimum. This is where the detachable driver housing will work well as the main housing can be mounted to a helmet whilst the driver and battery can be in a backpack keeping weight off the helmet. I still like to use the 20mm stars for the xml as they do a good job of transferring the heat away form the led to the housing. Perhaps if the make 14mm copper pcb's it would be better again.

Once my 1mm polycarbonate arrives I will be able to make the front cover.

1 what said:

My latest ugly MTB creation is at:
Not a very good idea of the output with that photo. In real life it looks much brighter with longer throw. Excellent for off road use.

Click to expand...

Mate looks like your light puts out plenty of light and that red rear will certainly attract the attention of cars. I find in the bush that due to reflection and leaf colour that the lights don't need to be as bright at a road light.

This is the light I have been using a bar light for some time and is still my favourite for light output . It s a 7 up with 4 xpg / 3 xpe leds running from a maxflex. You can see the battery pack under the stem. I either run 4s1p or a 4s2p depending on the ride duration. I also run a triple xpe on my helmet for looking around corners.

Nice!
Remind me not to meet you "head on" on a dark night.
I suspect my night vision would be shot for the rest of the ride.
Many thanks for the info on the connectors from RS. Mine arived today and they are the best looking (and best built) connectors I've ever purchased for DIY use.
Now I have to build something to justify the expense!

The beamshots of the Double XML with Regina reflectors @ 2.8A are very nice. Well done.

I took some beamshots tonight and compared it to my 7 up light. I must admit although the 7 up is still brighter with more throw when driven @ 1300mA, the twin xml @2800mA is very impressive, only being not far behind the 7 up.

The white fence is at 115 meters(1st and 3rd image), the and horse is at 55 meters and the big tree is at 87 meters (2nd and 4th image).

Twin XML @ 2800mA




7 Up XPG / XPE @ 1300mA

Nice beamshots and as far as I know a CPF FIRST - A horse!
Strange....I didn't notice any warning lights on him.

That is a sexy looking light!

Thanks for the comments guys. I am certainly looking forward to finishing the light and taking it out on the trail.

How would this output and spread compare to some of the new xml single 18650 lights that have come out? I am using a Zebralight sc600 on my helmet and it pretty much lights up the road at 500 lumens.

Regards.

MY said:

How would this output and spread compare to some of the new xml single 18650 lights that have come out? I am using a Zebralight sc600 on my helmet and it pretty much lights up the road at 500 lumens.

Regards.

Click to expand...

since reflectors seem to be the best choice the XML so far I can not see why it would be that much different. There have been only a couple of xml specific optics made so any torch manufacturer using an xml may have already designed a reflector better than the one available to diyers so the beam might be better.

As we all know it is the amps fed into the xml that give it the brightness so obviously an xml driven @ 3 amps is going to be pretty bright. This is why the drivers I use have multiple power level so the output can be tuned to the terrain. On a wet bitumen road I use full power but out in the bush riding on clay soils I can use 1/3 that power because so much light gets reflected off the ground.

Hi Brad72,

I'm interested in your use of the Regina reflectors. Did you find a chip that the Regina's little mounting lugs fitted into or did you have to cut them off and glue the reflector down? I have not been able to figure out what these lugs are supposed to fit in to...
Thanks,
Sam

Hi savvas

The Regina was made to fit onto a an xpg led and there were a few pcb's that had the holes drilled for the 2 legs to fit into. Most if us just cut the legs off and glue the Regina to the the pcb with non conductive epoxy.

When using the Regina with an XML you have to cut the legs off and drill out the hole to about 8 mm so the regina can fit over the XML die and sit flat on the pcb. You can achieve this by using drill bits, starting at 4.5mm and working your way up through the drill sizes or by using a dremel and plunging a cone Shaped stone into the original hole to make it bigger.

But until they make optics for the Regina which will be some time away I think since the have only just got the xpg stuff sorted this is our only option. If you want to use standard optics I have found the xpe optics to be pretty good since the XML is about the same size

Brad

Hi Brad,
Thanks for this bit of insight. Although I have restricted my activities to XR-Es thus far, I have a couple of XP-Gs set aside and some Reginas - I thought maybe that I had bought the wrong ones as they didn't match up with the drilling in the pcbs! I had in mind a very small light built in half of the smallest Hammond case I could find. I may of course have to put extra fins on it somewhere - maybe underneath if I cab find a low profile heatsink. I'm envious of those who have something other than hand tools to work with...

I'm interested in your choice of the Lflex driver for a future light running off 7.2V. Is the Lflex a boost driver or are you just planning to run Vin just slightly above the voltage of your series leds (which I presume would be 6.5-7V)?

Finally, what's the difference between the Regina's and the CRS optics please? You obviously prefer the Regina's - I presume for their obvious through - but how did you find the CRS, particularly the SS version?
thanks,
Sam.