DQG tiny 4 18650 triple mod

Great mod!

Great work!
I’m dreaming of build my own triple, dunno when. LOL.

What kind of solder did you use? Switching from lead based to unleaded solder should help both with elevated temperature and thermal conductivity(especially those heatsink plates soldered together). Here is the table of (almost?) all solder alloy types with melting points, and thermal conductivity for more common alloys:

Sn-Pb37 have thermal conductivity of 50.9 W/(mK) with melting point of 183C whereas Sn-Cu3 have 70.4 W/(mK) and melting point around 227C
(pure aluminium for comparison have 240 W/(mK) and copper about 400 W/(mK))

I know that there are some durability drawbacks in using unleaded solder but mainly in low temp environment so not exactly the flashlight related :wink:
I’m not familiar with any issues within flashlights. Anybody have any experience?

Wow, I was totally unaware. I thought lead based solder was the way to go and is what I used. Thanks for pointing this out!

I added thermal paste (sipik) and (more) properly resoldered the two wires. It didn’t happen again, but offcourse I was lucky it didn’t cause a short.

A 20% temperature increase in the solderbond and better conductivity is nice, I’ll scout for some Sn-Cu3 solder!

After 20secs on turbo (stepdown doesn’t seem to work for some reason, not even at 90secs :wink: ) the light get’s too hot to hold. But maybe the solder is nearing 180C right next to the LEDs…?

Does this type of solder need another solder technique, apart from a somewhat higher temperature?
Isn’t solder cracking an apparent issue with these lead free solders in flashlights, since they have a lot of warm/cold cycles?

I think most of us use lead based solder because it’s lower melting temperature and wetting properties is just easier to work with, there’s also easy availability factor and force of habit. No different soldering technique is required(or at least I do not use it) but higher temperature can require more power to work comfortably. With RoHS directive implementation in EU all current LEDs conform to lead free soldering requirements and major flashlight manufacturers should use lead free solder for that market. I am not aware of any problems with lead free solder in LED applications, but I do not reject the possibility. I had no need to reflow LEDs for high power flashlights yet, I did it for single AA lights so I used lead based solder I had on hand. It’s also worth noting that higher required temperature combined with makeshift temperature control (or lack thereof) poses greater risk of LED damage. But then again - pioneers are the ones making history :wink:

There’s also this thread here: Thermal conductivity of solder and pure indium is proposed as a solder because of superior properties (157C melting point, 81.8 W/(mK) thermal conductivity). But it seems it was not put to test ultimately.

I’ve got all the new components in, so it was time for the next mod on the modded DQG! :partying_face:

New parts:
20 AWG wire (18 was too thick for the center hole, too lazy to drill it out…)
BLF X6 Attiny25 driver (Banggood)
Atmel Attiny85 (ebay)

First I flashed Narsil to the Attiny85.

Then I desoldered the AT25 from the driver.
You can see, there is quite a size difference in the MCU’s

I added solderpaste to the driverboard

I bent the AT85 paws in a little and reflowed it to the driver, with my soldering iron.

Then I soldered the 20AWG LED wires to the driver.
Connected the microswitch to AT85 pin #2 and ground with thin silicone wire this time.
I’ve never been so happy with 2 blinks, the first sign of Narsil functioning. :+1:

After the first assembly, the switch came loose. So I glued it in with Sipik.

Then I soldered the LED wires in place. At first I got a short between the - Driver to LED wire and + on the noctigon. I added kapton tape to the top of the driverboard and solved the shortcut. - touched the copper heatsink and caused a short somehow :question:

Thereafter I reinstalled the GITD tape, originally installed in the DQG.
The light switches off! All works very nice. I love this firmware! Thanks Tom E, awesome job :beer:

The moon on level 1 I really like. It is so low! With the UT-210E I can allmost not even read the difference in moon vs off(parasitic drain).
Makes it a nice locator light at night. Lowest moon mode I’ve ever seen, love it.
In the picture below, moon is actually on!

I changed the temperature stepdowm delay in Narsil to 1 Sec. The light is way more managable now. However at 13.5A on a 30Q battery it still gets too hot to hold in about 10 seconds.
I’ve put a 3400mAh protected NCR18650B in it. Now its way more managable, safer and has higher capacity. And still stupidly bright :person_facepalming:

I use mode 4 with changed setting (moon+) 1-10-35-100.

@Firelight2, the thermal paste did solve the desolder problem. Now with 20AWG wire as well, I seems very oke.

So no need for other solder I guess.

Mission accomplished!
(for now :person_facepalming: )

Great :slight_smile: I will try changing to some of my fet+1 drivers to attiny85 and e-switch with narsil !
Do you have a EU source for the attiny85 ?

Dutchee, fantastic write up for this phase of the mod. Really appreciate the pics, and happy it is all working for you…

You can buy them at mouser. But due to the shipping cost, I bought a few from ebay.
These are the ones I used:
Ebay 5pcs Atmel Attiny85

Nice driver mod. I admire you guys modding and building these items.

Sorry, I think I missed this post…

Yes, with a tiny solder tip it should be doable.

I had to resolder the black wire to the switch while it was glued in the head. It came loose when I removed the driver to add the kapton tape. So I think desoldering should be relatively easy.

When heating the whole head as you mentioned, you might melt the rubber boot over the e-switch. Also the original glue might burn. I think its safer to remove the driver before the LED reflow.

Excellent job on this mod! Wish I had one of these lights, because this mod looks great for it.

Let me know f you have any flaky problems with the light - mode changes, going in/out of strobe or hi, etc. Most Tiny85 builds I had to tweak things to get it working reliably - add another 10 uF cap stacked on C1, or air wire a 0.1 uF cap from pin #4 to pin #8. Now could be more of a problem with the SIR800DP FET's I use, but probably still happens with regular FET's. Richard's new MTN-17DDm driver that supports a Tiny25 has several changes to properly support 25/45/85's.

Thanks for the nice replies, guys!

On the pannie cell it doesn’t overheat. When allmost burning my hand, it steps down at 30sec’s. On 35% it slowly loses the excessive heat. I don’t plan on testing this in a pocket though… I still have to do a tailcap reading on the pannie…
It does heat up real nicely all the way to the tailcap. But the cell stays quite cool, unlike in the stock DQG where it serves as a heatsink…
On a 30Q cell the strobe is so bright, it actually gives the same effect as a stroboscope in a discotheque!

@Tom E: Besides the somewhat high temperatures, I didn’t notice anything flaky, not even once. All modes work flawless so far. Really the nicest U.I. in a light I own. I usually EDC small twisty 10440 lights, so the lack of unexpected mode changes is something I’ll gladly get used to. Really nice with the e-switch.
But if I’ll notice something strange, I’ll give you a head’s up :+1:

Edit: Tom E just made clear there is not thermal stepdown in Narsil, so the heat has nothing to do with any flaw in the driver or Narsil. It actually performs 100% in a super hot light :+1:

That's all good then. I've had the same luck with a few drivers converted to 85's, but more recently, I just do the cap mods, not wanting to take a chance. The FET tused is a big factor in this.

Absolutely outrageous! I have two Tiny 18650’s, have wanted to mod one forever. This is a little beyond my present skill, but I enjoyed your post immensely.

Awesome job Dutchee!

Question: How do you reflow an MCU from a driver board? I tried it once on a Nanjg 105c and ended up destroying the pins. Do you just apply the iron to the plastic package and hope it melts the solder? What kind of iron do you use?

@ rmkline: Thanks for your enthusiasm!
Just order all parts x2 and see how far you can get. You already have 2 hosts :laughing:

Firelight2 is part that got me into this mess :person_facepalming:
Just like his nice build review on #3, I hope this opens doors for more mods on the DQG 18650. I haven’t found a better host so far… It actually drives the heat out better than I expected. I usually EDC titanium lights, but these suck at thermal conductivity.

@Firelight2: Thanks!
I place the driver on the two wooden blocks, like in the pic’s.
MCU side up, solder tip between the blocks under the driver pushed against the + battery pad, just slightly lifting up the driver. I had some solder on the + pad, guess that helped in the heating process. Not needed though I think.
After about a minute or two you can pick off any component with a tweezer. You can see it’s ready when the solder turns shiny. Don’t drop the driver at this point :smiley:
I cleaned off the excess solder with copper unsolder wick, working from the top.

I bought my iron at a local hobby shop at around €20, will let you know wich type. I’m not home at the moment. It’s got an analog temp. selector wich I use on high most of the times.

Edit: I used this solder tin paste for the reflow of the AT85:
Ebay solder paste

Wow thanks for the tip! So all I need to do is apply my soldering iron to the + pad on the underside of the driver :sunglasses:

I figure my 40w cheapie soldering iron should be hot enough. But if not I suppose I could swap to my 60w iron.

Hm… wonder if I should learn how to flash driver firmware.

Haha, that’s not a question, is it? :beer:


I wish someone would come out with an e-switch driver with temp sensor. Something like the H17F, but for e-switches would be perfect. Hint, hint …. if you’re reading this thread DrJones :money_mouth_face: :money_mouth_face: :money_mouth_face:

I wonder if I should mod my DQGIV into a triple.

I like the stock DQG IV much better than the DQG III, but I still find the UI annoying. The light would probably be better as a small triple!

Alternatively, I could mod my BTU mini titanium into a triple. It looks like a slightly longer DQG mini, but made of out of titanium. It would actually be possible to make this one into a non-triple with a different driver and emitter since unlike the DQG this one has an actual separate star for the emitter. Downside is the titanium. The head gets too hot to touch even with just the stock 2.8 amp driver.