MV's Return to Saber Building!

[Master Valon]

Hello, TCSS! After a long hiatus (due to a blow to my self esteem, which was caused by my failed 10W Deep red stunt build) I am back to saber building, and glad to be back. Soo......here's my planned build. I have a replica Graflex that I wanna make into an uber-bright stunt. I've done a crap-ton of reading in my absence (special thanks to Fender and his 10W thread!) and I THINK I have nailed down the generalities of what I want my build to be. However.....I am operating on a few assumptions here, and would like to check it out with you guys. I want to use the new Quad-Rebels that Luxeon has put out, specifically a 4x Cyan (or a BBBW, for a OT-true sky blue/cyanish color). Now, my main question is can each LED on the Quad handle 1500mA? If so, I would then get two TCSS constant current drivers, each the 3000mA variety. Then, I would wire two LEDs together in parallel, then wire them to the CC Driver, supplying each with 1.5A of current. Then I would do the same with the other 2 LEDs on the PCB to another 3A CC driver. Which is perfect on paper, but run me into a big problem relating to battery solution. If I wanted any sort of reasonable run time, which I do, I would need a crazy capacity to withstand the constant 6A draw. I whipped out the ruler, and concluded I MIGHT be able to squeeze 2 18650s side by side together in the Graflex, but might not. If I can, I would get 4x 3.7V 2600mAh packs from TCSS, wire 2 of them up in parallel to get 2 separate 3.7V 5200mAh packs. One pack would power one driver, and therefore 2 LEDs at 3A, leading to approximately an hour and 45 minute runtime, and the other pack would power the other driver leading to the same runtime. But, if 2 18650s can't fit side by side in a Graflex, I would just get 2 packs from TCSS and have one pack drive the 2 LEDs at 3A each, leading to approximately 50 minutes of runtime. OR, I could look into 26650 size cells, which are accurately rated at 4000mAh. I would only need two of those in stick formation. So, my main questions are:

1.) Can each LED/die on a Quad Rebel Cyan take 1500mA?

2.) Can 2 18650s fit side by side in a graflex?

3.) Are 26650 size cells appropriate for saber use?

4.) Would I need a DPDT Switch to turn on both circuits at the same time?


Thanks, guys!

[Silver Serpent]

Personally, I'd go with a seriallel setup. Wire two of the dice in series, and then wire the other two dice in series. The wire the two series sets in parallel. You'll only need 3A and a single CC driver to drive all four dice at 1.5A that way. Keep in mind that the Vf of the whole setup is going to be equal to TWO of your dice, instead of one. So somewhere in the vicinity of 6-8v (I don't have the specs on the quads handy). A pair of 18650s should do just fine. I don't know if they'll fit side by side in a graflex.

[Johannes Huber]

What Silver Serpent says is something about serriallel is that I just tried last week using the TCSS LED driver at 3000mA. I can't say whether the cyan LEDs will hold up but I can say that the "cool white" 4 LED does hold up. I should mention two things though: 1) The amount of heat given off is...respectable, my own solution has been to modify the heatsink and that seems to work, but I wouldn't leave this running for a long time (I haven't tried more than about 8 minutes yet). 2)Make sure you don't look directly at the lit LEDS if you do this. Seriously. It gets bright enough if not diffused to be potentially painful and leaves you seeing spots for a good 5 minutes after just a few secs. . One other thing, the setup I'm using is working just fine with one of the 14500 4 packs from TCSS, so I don't know if the 18650s are necessary (since Silver Serpent mentioned a size constraint possibility in the Graflex). Hope this helps in some way.

Johannes

[Master Valon]

Genius. That's all I can say! That sounds awesome. So, I will wire the LED (which I'm now thinking should be a BBBB, to avoid bad binning potential with a CCCC) in series-parallel, with B(1)+ bridged to B(2)- and B(3)+ bridged to B(4)- on the PCB, and B(1)- wire to B(3)- wire, and B(2)+ wire to B(4)+ wire? Then, with the 2 left over leads, I would take those and connect them to the LED outputs on the CC driver? Then, the 7.4V 2600mAh 2 18650 cell pack sold at TCSS will go to the driver, and I'll just wire in a switch (probably a momentary tactile to go under the red button on the Graflex) in between the battery pack + lead and the + battery pad on the driver, and I'm good to go? I think this is what you guys meant. If so, great! I totally get it. My only remaining concern would be heat dissapation. I could probably get a 2nd heatsink to attach to the screw in copper heat sink that goes in the Graflex adapter, cuz that one is tiny! I would secure it with some Arctic Silver, but I'm afraid that some thermal compound and two heatsinks wouldn't quite do it. Should I consider wiring in a smaller circuit to power a small fan or something? I could drill an opening on the bottom of the Graflex, since I'm going for an ESB version, I will be getting a Kobold D ring assembly that could cover it. But the Kobold is beveled, so it wouldn't seal off an opening if it was placed above it, it would just obscure it. Then, I could place a tiny fan up by the LED heatsink, but point it down the length of the hilt, so it'd be sucking the excess heated air around the LED and venting it out the bottom. It'd also work to vent out the hot air around the driver, which would also be mounted to a heatsink. I could even dremel out a slit in the top cell where it fits under the clamp, so the card insert would (again) obscure it from view, but still open an area for air to flow out of the hilt. Would any of this work?

[Johannes Huber]

Hi!,

I actually went with a pair of the TCSS MHS heatsinks (the six hole variety) and the gen 3 blade holder and the Arctic sliver and that seems to work, at least up to 8 mintues or so. Haven't tried beyond that, but so far, so good... I just disassembled the TCSS driver from the "test" LED set, but I haven't yet removed the "Use" LED from the saber beyond disassembling the saber and detaching its JST connector, but if you like, I can PM you a picture of the wiring as it presently works with resistors. It's really nothing but an adaption of FenderBender's 10W LEDEngine layout, but if it helps, just let me know.

Johannes

[Master Valon]

That'd be great, Johannes, if you could PM me that pic. Oh, and yes, I would be using JST connectors for pretty much every connection (LED to driver, battery to driver) as well.

[Johannes Huber]

Hi!,

Just wanted to let you know there will be a slight delay on the photos because the one which actually shows the up top wiring is too blurred to be of any use (they're cell phone shots), so I have to borrow a camera real quick to get the shot. On the bright side, I found that I hadn't disassembled the trial piece as completely as I thought so there will also be a shot of the "test bed" where the wires are much longer and more visible and it is mounted to a single heatsink. Unfortunately I did disconnect it from the TCSS driver, but that hook up is pretty straightforward.
I did also have one other possible thought: You could run all four LEDs in parallel with a single 18650 battery. There is a way to do this where you use the holes in the center of the star base and the only hitch is you need to drill through the heatsink for it. I did this and take my advice: ask Tim to do it for you, it's kind of a misery to do...

Johannes

[Master Valon]

Okay, no prob on the pics. Whenever you get them in will be fine. And in regards to the single 18650 idea, well, I guess I could, but I already placed my order with TCSS and Luxeon, so the parts are already on the way. Here's what I ordered:

TCSS ORDER

Constant current LED driver (3000mA, Momentary) 1 $50.00
SPST Momentary tactile switch 2 $3.00
7.4v Li-ion 2600mAh 18650 Battery Pack 1 $22.50
3.7V-14.8V Li-Ion Smart charger 1 $21.95
Tamiya to JST charger adapter 1 $1.50
26 gauge wire (25' Spool) (Blue) 1 $5.50
1/16" Heatshrink tubing 5 $2.50
26 gauge wire (25' Spool) (Black) 1 $5.50
JST connectors 6 $3.30
Star thermal tape pad 2 $1.90


LUXEON ORDER:

Khatod 10° 23mm Narrow Beam Quad Optic with Integrated Mounting Legs (Modified PL115106)
1 $14.50 $14.50
LPD25-25B 25mm Square x 25mm High Alpha Heat Sink - 12.2 °C/W
1 $5.34 $5.34
SR-08-M0100 Green (530nm) Rebel LEDs, Mounted on a 23mm Round Quad CoolBase - 644 lm @ 700mA


And yes, I did indeed change my mind completely regarding the color. I figured 1.) if I am going for the brightest possible, I should probably go green, and 2.) this saber doesn't have to be an exact, screen accurate replica because its going to be for my generic Jedi costume for the Rebel Legion, and 3.) I will wire it with JST connectors, so if it bugs me later, I can just make up a BBBB LED module and have a drop in hot swap sort of setup. But anyway, how does the rest of the order look? Oh, and I got a pretty nice soldering station from mpja.com, like the one Fender linked to in his 10W tutorial, except its the step down from that one. Instead of having digital temp. control, its analog (but also $20 cheaper!), as well as a spool of 60-40 rosin core lead/tin solder.

[Johannes Huber]

I'm no expert (I've only played with this stuff about 5 months) but I think it looks right. Certainly it looks a lot like the order I put in with Tim and pretty similar to the Luxeon order as well. The only thing I differed on was using 28 gauge wire since it fits more easily into the holes in the heatsink (I think 26 ga. should work too). I notice there isn't a recharge port but there is the JST to Tamiya adapter. Originally, I used that in the saber before switching to the recharge port. The JST works fine and can be easily split off from the battery as a seperate plug so you don't have to disassemble anything, and with a little work can be woven through the battery holder chassis parts to keep it out of the way so all you do is unscrew the pommel to get at it. I added the charge port mainly because I was curious to see if I could wire it up properly...
I personally think the JST swap outs are a great idea, that also covers you if the LEDs, or anything else, dies for whatever reason, as well as letting you tinker without having to automatically take everything apart. I used to consult on military sidearm/rifle design about 20 years ago and the big push in firearms back then was toward a modular system where a dead part could just be pulled out and a new one snapped in, I guess the design paradigm stuck with me...
The reason I thought of the single 18650 was it suddenly occurred to me that if you wanted, and were tight for room, that it would also free you up to use a Nano Biscotti if you ever wanted to add sound (I've never handled a graflex and am unsure of the amount of room). I know from trying it that the single 18650 will parallel drive the quad rebel quite nicely although I recommend putting a resistor on it. I tried it without one as part of my testing process and smoke immediately starting coming off the LEDs, though boy where they bright. They still worked quite well when I turned them back on with a resistor, but apparently Mr. Plector's advice about always use a resistor proves itself again. Tough little LEDs though...
Will try to PM you the pictures tonight.

Johannes

[Master Valon]

Sounds good, man! Update on this. I went to Home Depot to get parts for the chassis, and all last night I spent constructing it. I got a 12"x1"PVC sprinkler riser, 2 6"x3/4" PVC risers, and 2 copper caps. Using limited hand tools (a hack saw and pliers) I cut a roughly 2" slot at the tip of the 1" PVC, and a roughly 3" rectangular window toward the bottom. Then I fashioned a C-Clip out of the 3/4" PVC and super glued it toward the top of the window, to act as a snap-fit holder for the 18650 pack. Then, I took one copper pipe cap and super glued it (wider part facing down) into the 1" PVC right where the slot is. This will be the driver heat sink. The way I have it in my head, I will super glue the PVC chassis to the inside of the top cell of the Graflex, so it butts right up to the bottom of the adapter. Then, I will run 2 JST connectors that come from the LED and the switch, respectively, down from the adapter, past and over the driver heat sink, into the PVC chassis, past the battery pack, and then bend them around so they are pointing up toward the driver, and are toward the bottom of the window. Also, the JST connector from the battery pack ( which will be pointing down toward the bottom) will loop back and point toward the driver, like the other two so far. Then, all I would have to do is wire up 3 JST connectors with 6 wires running from (respectively) the switch, battery, and LED pads on the driver. These would run under the PVC, and all 3 would be affixed toward the top of the window, pointing down, toward their counterparts. This way, all components would easily be swapped out, plus the wiring would be pretty clean and there would be no risk of pinched wires, or anything. I will try to take pics of the chassis when I can, but be warned.....it looks like crap. But, it'll do its job, so I am happy with it. But, its no piece of art, haha. trying to cut a 1/2" of PVC with manual tools is not fun, or precise.


Now I'm just concerned with heat. For the LED, would the current copper screw in heat sink, the aluminum adapter, and loads of Arctic Silver do the trick? Because that's all I have room for.....