Review: Rustu RX-40 Quad XM-L Single 26650 Flashlight from DX

@ChibiM: LED's are in parallel, each positive pad is connected, and each negative pad is connected.

@GottaZoom: I gave it two stars due to to cruddy output levels (under-driven on high, no medium - a 2nd high, and a low mode not low enough), poor threads, poor heatsinking, and most of all the high cost. If the cost were more like $25 I'd probably give it 3 stars. I was actually trying to give it 2 1/2 stars, but couldn't find a 1/2 star symbol!

The output on low surprises me. On low it's only giving about 0.25A per LED, yet the output is still quite bright. That doesn't seem right. I did my current measurements with my "good" meter and thick leads too.

-Garry

Ahh - this is the mystery 26650 light! Nice review! Sure is weird to see higher amps on a KK INR... Wonder what's goin on there, because the driver seems to be sort of direct drive. With the cells rattling, may be perfect for a Moli 26700. It seems to be easily upgradable in amps (Nanjg to 4.9A or so), and for $20-$24 bucks of 4 XM-L2's on copper from IOS.

If the heatsinking were there, yeah, but I don't see it worth putting much money on it.

-Garry

Might be worth the $5 or so driver upgrade, for me that is. I'd go with 4.55A or 4.9A, then do the usual copper braiding of the springs, and other resistance reducing treatments and see if it would get to 4.5A on the KK's. It's not much of a bump, but with a nice mode set, it would make it more useful.

Actually, if the cells rattle but you got higher amp readings with the spring compressed, then this explains the low brightness because when it's assembled, it's probably running lower amps then what you measured, maybe? A conductive filler piece to extend the spring may make a big difference.

I had not seen this light before, and I had missed JMs review of it too, which had a lot of the same information.

Sounds like 2,5/5 is a decent rating.

But, based on what I have seen from where I am sitting it looks like a great mod host IMO.

Humongous space for driver/drivers, easy to take a part. Backside of the reflector is not flat (easier to get the emitters well focused despite using thick wires). large switch, driver might be easy to resistor mod (if you wanted to live with it that is), good beam, etc...

All the cons you listed are easily fixed in the modding process. To me it also seems that there is nothing wrong with the heatsinking. As far as my experience goes, its perfectly normal that the front of the head gets a lot hotter than the heatsinks on these lights. Unlike a thrower where the emitter is usually close to the heatsinks, all the emitters are quite near the front and far away from the heatsinks. That fact that your lights gets very warm in the head after 5 minutes despite the "low" high current is just a good sign. (I may be wrong though, but it looks good from where I am sitting)

As far as price goes, its not bad, as a mod host. Most XM-L triple emitter lights are usually 30++. Most quad lights are usually 38$++. For a quad XM-L this have a quite large head, which puts it in a more expensive class than the cheapest quad lights..

Ill probably pass though, got an Shadow SL3 incoming. But if I had not bought that (as a mod host) I would have considered this (as a mod host)...

Might even consider it some time in the distant future... ;)

Thanks for the review Garry!

Cheers..

Thanks for the review Gary. I really like that light. I would just toss the driver and make it direct drive with emitters wired in parallel. That is what I did here and it is one of my favorite lights.

Thanks for the review, Garry! I agree with pretty much all you say about this one. I reviewed this a while back and wasn't impressed either. As I recall, I did find it to be extremely comfortable to hold. Other than that...meh.

Nice review Garry!

If you forget stock, what do you think about it as a mod host?

Ehhh…heatsinking isn’t the best and the single 26650 cell format means you can’t go too crazy as a decent quality single battery can only sustain 5 or 6 amps draw so it’s kind of pointless. You could crank it up to 9amps possible but it would only be good for a few minutes and would be hellish on the cell or overheat the light or even both. Consider the high price as a mod host and you are better off modding a King or a Kung. Hope that helps.

What is wrong with the heatsinking compared to similar lights?

Looks way better than the typical convoy with screw in brass pill (I rarely hear about complaints on them). The front of the head where the emitters sits is a one piece aluminium construction, isnt it?

A bit if lapping of the head could be beneficial.. but otherwise it looks good. Or am I missing something??

9-10A is "daily routine" for my Sony 26650 (rated for 50A, they dont even break a sweat at 10A). Could even use King Kong.

With 4 emitters, Vf is less of an issue compared with a 3 emitter light. Is there a reason why a smaller SRK/Kung light should deal better with the heat?

I love my kings, but grip could be more comfortable, and holding around the warmest part of the light isnt always that great in the long run depending on the weather. The rusto seems to take care of both issues, and its got larger reflectors, and a larger head (more surface area to get rid of heat)

Cost could be superlow of you go the budget route. 4x Noctigons + 1x East092 (assuming you get a good one)

Battery life is overrated... 0:)

Flashoholics brings more flashlights instead :bigsmile:

(or just bring a spare battery if you know you are going to need it)

The head doesn't have that much heft to it for heatsinking. I think the aluminum where the emitters are mounted is only a couple mm thick and it's anodized (well that can be removed). The reflector assembly has heft, but it can't transfer the heat anywhere. The threads from head to heatsink are just thin and minimal for contact area to transfer heat. I felt NO heat whatsoever being transferred behind the head after 5 mins (when the bezel & glass were quite hot.

-Garry

I like the large head but I think it needs a second cell for more current/better run time. Thanks for doing the review!

So I still have this light sitting untouched since the review. What would you do to mod it; give me some ideas. Keep the ideas “budget” though as I don’t want to dump a lot of money into it.

Concerning the driver, can I just short the current sense resistors (or replace them with a really low value) to boost driver output? The R130 & R010 ones, right?

-Garry

Wow , i just noticed this is a 5 yo flashlight review ! Very interesting !

Yes , you can try adding another resistor over the 2 resistors you mentioned . These are probably limiting the current . you can try adding a resistor about 150mohms , or lower value . Edit : I thought one resistor was 100mOhms but it’s 10mOhms . Hmm… I don’t know if these are the sense resistors .

I would do a full mod on such a gem , 4 brand new leds on copper mcpcbs and a fet driver :slight_smile:

That was my thought too. Which emitters though? No sense making it a thrower, right? So aim for a big flood of light?

I’d like to change/short sense resistors on the stock XM-L’s to start; so can someone confirm what to do on this driver? Or I could just direct-drive it :smiling_imp:

-Garry

Lot’s of choices …

For a good tint (neutral white for me) and output combo , i would go for xpl v6 3d probably , which have very good output … Nichia 219C are another option of course .

For maximum output : xp-l2 or sst-40

These , and a fet driver would be awesome .

Is the driver 17mm ? If yes , you could use the cheap BLF A6 driver from Banggood …

20mm driver (had to read back in my own review). Weren’t there 17mm to 20mm brass adapter rings available back in the day? Think I have something like that. 219C’s sound more along the lines of my budget, but what kind of output difference would you expect between 4x 219C’s and 4x XP-L / XP-L2’s? Remember, this is a single 26650 light, so it may be severely limited trying to push 4 XP-L’s, whereas it should push the 219C’s much easier (correct?).

-Garry

Yes ther are still adapters like that . You can get a 20mm driver from MTN but of course it will cost more .

I haven’t build xpl quad but that’s what i think . xpl will be brighter for sure . For example : Using values from the datasheets 4* xp-l v6 at 9,6 amps will have 3700 lumens output while 219C (D240 bin) only 2700 lumens . 121 lumens/watt vs 81 lumens/watt .

A good 26650 cell will handle both 219C and xpl fine . I know for sure there are 20-30 amps cells .

I would put in 4 dedomed XPL or XPL HIs. It’s just a matter of what you want the light to be. Domed XPLs will give the same size beam as stock, just brighter. The XPL HIs will give a beam about 2/3 the width, but nearly 2x more intense than the XPLs.