Another XM-L Sled light- boxcar design
Here's sled light #2.
I simplified the design a bit this time by using a "box" on the sled.
I got a piece of 5/8" square tubing, and attached the XM-L LED to the front, and the L-flex to the back. I cut a slot in the top so there's no thermal path directly from LED to L-flex.
The build was easier, as parts can be soldered before the box is attached to the sled.
I also used a Laura RS optic instead of a Regina and plexiglass cover, which was a touch simpler.
Same helmet/ headband bracket which acts as a heat sink too. There's another bit of heat sink under the housing.
I placed thermal grease between the sled, housing and bracket, and sealed the back of the sled with black silicone.
Some post-build thoughts:
The sled was a little short, so I added a small extra bit of aluminum. Still a bit cramped once finally assembled.
If I did it again I'd use some 1 1/2" L-shaped aluminum for the sled, and the bracket. I found a nice bar of that at Canadian Tire.
Another alternative to the boxcar- I might use another longer L-shaped segment for the LED bracket, and mount the L-flex flat on the bottom of the sled. The light would be a bit longer, but there would be more room for the build.
I had intended to use a Quazzle L333 for #2 but had some connector issues we're sorting out, so it'll be #3. Should be smallest yet, but not a cramped build.
Last edited by Ofroad'bent; 04-10-2011 at 11:35 AM.
Looking good. I love these sled designs.........(matt, you there?)
I've been toying around with a similar idea.
I have alot of different sized tubing's here.
Look, whatever happens, don't fight the mountain.
Matt and I were bouncing around the "box" vs "L" LED bracket shape a bit.
Originally Posted by savagemann
A 1" U-shaped sled's fine for an L333, but for XM-L and L-flex, 1.5" length would give more room.
The 1" outer size is about the minimum to fit the switch and the cable gland on the back.
Every time I see one of these I wonder why I try and do what I do.
Nice work Ofroad'bent
In your first picture, the LED and bottom of the sled do not look square and there is kind of a bend in the bottom of the sled. Does that get straightened out when the sled is pushed into the body. If it doesn't wouldn't that make the LED a bit misaligned to the optic?
Good eye. The sled base was a touch short, so I added some more aluminum with a bit of thermal tape. If I'd used AA it would have looked more square.
Originally Posted by Vancbiker
The single bolt goes through the housing and sled and secures the box down too. It should be bolted down nice and square.
looking good Makes a lot more sense now I can see it in the flesh. What's the approximate surface area of this one compared to no.1, now that the sled's a little longer?
Now, what I'm really interested in is how the beam patterns of the Regina and Laura RS compare...
Savagemann - the irony is that it's Ofroadbent and Andy13 that have really taken this idea and run with it, all I've done since the 1st sled light is another 4 of the same. I do have a megasled light on the drawing board though...
The sled's a bit longer, but the Laura RS is shorter than the Regina + Plexiglas cover.
Originally Posted by mattthemuppet
I'm guessing 10 square inches + the heat sink. There's room for another sink on top and even one on the side if need be.
I'll see if I can get the first sled with Regina back from my buddy Goose and do some beamshots. The Laura's throwing a nice tight hotspot and a floody perimeter.
10sq.in isn't too bad.
so does the Laura give a smaller AND brighter hotspot than the regina? Without that annoying reflector cut off? How about the graduation between spot and spill?
I really should just build my own, then I'd find out for myself
Last edited by Ofroad'bent; 04-12-2011 at 03:53 AM.
Oh oh, just heard some news about my first Sled light, the one with the Regina.
My friend Goose was out with his team-mates doing some night orienteering deep in the woods.when one of their Ay-ups died.
Goose was proudly leading the way with his far more powerful XM-L sled light, when it apparently died with no warning. The second fresh battery didn't work either.
I'll loan him the new Sled light with the Laura while I try and figure it out.
surely Maverick was there on his wing to help out
Was thinking the same thing when I saw "Goose".
Originally Posted by emu26
that's a bugger. It'll be interesting to find out what went wrong - might show up a flaw in the design we haven't come across yet..
Originally Posted by Ofroad'bent
Just got the light back from Goose (Angus).
His wingman is Phatty, of the dead Ay-Up. No Iceman, Sundog or Mav.
I'll have to see what went wrong with the Gooselight.
One interesting thing I found right away after cutting the battery pack open- a possible short in the battery holder with built-in protection circuit. The power wire is *very* close to a contact on the PCB. Time for some more Liquid Electrical Tape.
The second battery pack I made up with no protection (but protected cells) isn't working on the Gooselight either, so there's still a light issue.
OK, turned out to be a wire that had separated from the LED.
I think there was some tension during final assembly, or Goose banged it around in a pack perhaps. I've re-soldered, and moved the wires a bit so they don't get rubbed or pulled.
The Boxcar sled has more clearance there, and some more flexible wires would be better too.
Luckily the Sled design is easily opened and re-closed.
Phew, I had visions of a blown LED or a cooked L-flex driver.
While I was fixing things, the battery pack's PCB is now better insulated, and re-sealed too.
If you get the ones from eBay, check the wiring under the cover.
Live and learn.
Last edited by Ofroad'bent; 04-15-2011 at 03:08 PM.
Boxcar fail and fix
It looks like the boxcar design is just too compact on a 1" square sled.
It works fine on the bench, but as Vancbiker noticed, it's a touch out of alignment until tightened. Once I tightened it the back of the L-flex pressed through the adhesive and occasionally shorted out against the box.
So, I took it apart and made a second L out of 1 1/2" Aluminum. This allows the L-flex to lay flat.
Lots more room now. It could have been a touch shorter, as long as there's room for the bolt in front of the L-flex.
The boxcar would work on a longer sled too, just not on the 1" square.
Last edited by Ofroad'bent; 04-18-2011 at 07:25 AM.
that looks a lot easier to work with and shouldn't make that much difference weight wise.
thanks for doing all the troubleshooting for us!
The fix looks good! Do you think heat will be a problem for the L-flex?
No more than if it's mounted anywhere else on the light, I hope.
Originally Posted by Dr.Mushy
The bottom of the sled is bolted to the housing and to the mount with its heat sinking holes, and there's thermal grease in between all the bits.
I haven't used these in warm weather yet, but plan on running below full power except when booting along.