2.3W Little Fathead (upgrade) - a flashlight is dead & a laser is born

[danefex]

Greetings Folks!

Here's my latest build & one of the most powerful handhelds that I own. I'm calling this gem my little fathead because that's exactly what it is, there's nothing more suitable for how it turned out

The Host - Trustfire TR-1200 5 Mode Cree Q5

I originally bought this as a flashlight last year because it was cheap for a 5 LED 1200lm flashlight. It's a 3x18650 unit so it stays damn bright for a long time. I was going to make it into a laser after I received it but I enjoyed months of heavy use from it as a flashlight instead. The fun ended recently though because the tailcap could no longer be screwed on the back of the host due to damaged threading from so much use & some mishandling. I needed to take it apart in the middle when switching the batteries but whatever, it was just a chinese cheapy flashlight. It also just died a couple weeks ago, no idea why or what happened. I didn't bother looking into what was wrong with it or fixing it because I have several other flashlights and I originally planned on making this into a laser when I got it. The only problem now was the damaged threading on the back. :thinking:

I soon figured that I could remove the back half of the body (2 parts to the center of this host) & screw the tailcap on back of the front half instead. Perfect, the tailcap screws on & off smoothly once again - except now the unit is shorter & won't hold 3 18650 batteries. :thinking:

After some measuring it turns out I can fit 3 RC123s/16340s or 1 18650 and 1 16340 - and I now saw this build could be done. Here's how it went... :beer:

Parts -
Trustfire TR-1200 Q5 Cree Flashlight
9mm 445nm diode
1.8A Mohgasm driver
Jayrob custom heatsink
3x16340 3.7V batteries / 1x18650 & 1x16340 (pictured)

After the flashlight was completely taken apart, the first thing I did was gut out the stock
driver & turn it into a blank battery contact board

Parts removed, I drilled a hole through the board to run the positive lead through to the
srping on the other side

I added both leads, negative soldered to board & brass ring holding the board and the
positive to the spring

I ran the leads through the massive pill

Mounting this board into the pill took a lot of force but it's now tightly pressed into place

This is how the driver is going to sit in the pill. This is the largest housing I've ever had
for heatsinking a drver so there should be no problems

Before mounting the driver I need to heatsink the resistors so there's enough room
between the contact & the caps to prevent any shorts in this circuit

A thick layer of thermal compound it used to create the necessary cushion of space
needed to mount high enough off the pill

After drying I can see the layer was thick enough, the caps wont touch the pill when
being mounted

Another thin layer of compound to mount the driver on the pill

Mounted, now it just need a good 1/2 hr to completely dry

After drying I soldered the battery leads to the driver

Now to the diode, going to solder the leads

Soldered, now to heatshrinking the wires & mounting the diode module into the heatsink

It's in, now to connect the diode leads

Soldered & ready!

I'm going to use these non conductive thermal pads for additional support when the
heatsink & the giant aluminum pill are pressed together

I'm also going to use a thin strip of padding to cover the regulator on the driver,
preventing it from shorting out on the heatsink

When this build is assembled, this is how the pill will press against the heatsink without
the gap of space. This is why the padding is necessary to support the open area around
where the driver is almost being 'smashed' between the sink & the pill

I pressed them together & added the crown, the laser is done & ready for testing!!

Mandatory 1st beamshot

Here's an LPM test to see where it hits using 3 16340 batteries


The laser starts blinking when it hits 2.3W which I assume is the driver overheating :thinking: This is dissappointing
after all that heatsinking WTF. I followed this up testing the laser with 1 18650 & 1 16340 to lower the voltage,
it doesn't blink now but the output also drops from 2340mw to 2289mw. It definitely surpasses 2300mW though
so I'm calling it my 2.3W little fathead

Thanks for reading!!! :beer:

 

[ryansoh3]

Re: 2.3W Little Fathead - a flashlight is dead & a laser is born

Wow, excellent build log!

Love the name little fathead.

+1 for you mate! (Edit: Which I mean when available.)

Cheers! :beer:

 

[Blord]

Re: 2.3W Little Fathead - a flashlight is dead & a laser is born

You should heatsink the ic side of the driver and not the resistor side. It is the ic that cause the blinking. I see also that the voltage of the two cells isn't enough for full output. These 9mm diode requires a high Vf to run at high current. That is why two cells give a little less output of the driver than 3 cells.

Still a good good job done destroying a flashlight and creating a laser. :beer:

 

[ryansoh3]

Re: 2.3W Little Fathead - a flashlight is dead & a laser is born

Oh yes, and make sure your batteries don't explode when you're using a 18650 and 16340 together.

Cheers! :beer:

 

[danefex]

Re: 2.3W Little Fathead - a flashlight is dead & a laser is born

You should heatsink the ic side of the driver and not the resistor side. It is the ic that cause the blinking. I see also that the voltage of the two cells isn't enough for full output. These 9mm diode requires a high Vf to run at high current. That is why two cells give a little less output of the driver than 3 cells.

Still a good good job done destroying a flashlight and creating a laser. :beer:

Both sides of that driver are sinked, the resistor side is mounted to the pill & the IC presses on the back of the heatsink with a thin strip of that thermal padding. I didn't think it'd matter which side was mounted to the pill so I chose the resistor side, but from what you're saying - I'm guessing now the IC possibly isn't pressed on the main heatsink (?) That can't be though, it feels like there's a lot of pressure squashing the driver :thinking:

Oh yes, and make sure your batteries don't explode when you're using a 18650 and 16340 together.

Cheers! :beer:

Yeah thanks, I just got a haircut so let's hope that doesn't happen :beer:

 

[Blord]

Re: 2.3W Little Fathead - a flashlight is dead & a laser is born

1.8A Mohgasm drivers are pretty robust. People build these drivers in the C6 host and still no blinking. If your laser is blinking that is usually a sign for overheating driver or a faulty driver.
Seeing your massive heatsink it could be a faulty driver.

 

[danefex]

Re: 2.3W Little Fathead - a flashlight is dead & a laser is born

Thanks Blord. I'm almost positive the sinking isn't an issue so you could be right about the driver, but I'm going to open the host up & see if there's contact being made or not. If it turns out to be the driver I can easily replace it after prying it off the pill & unsoldering all the leads, I just need to get my hands on another 1.8 or 2A driver :beer:

 

[jander6442]

Re: 2.3W Little Fathead - a flashlight is dead & a laser is born

Flip the driver over onto the pill that thermal tape or whatever is not cutting it you must have robust heatsinking on the Moh 1.8A. I have tested that driver and just guessing if you were to adhere it to the IC to heatsink you would get longer runtimes than what your experiencing now.

 

[danefex]

Re: 2.3W Little Fathead - a flashlight is dead & a laser is born

I just checked it inside, it still seems that the regulator is firmly sinked to the main diode heatsink but as I tested it again it still blinks. I'm going with both your recommendations of flipping the driver. :thanks: Unsoldering & remounting a mohgasm is easy to me so I'll take pics & post the outcome sometime later or once I can get a good half hour of uninterrupted time

 

[lowell389]

Re: 2.3W Little Fathead - a flashlight is dead & a laser is born

Nice build!
I'm sure you will figure out the driver issue .

 

[lazeerer]

Re: 2.3W Little Fathead - a flashlight is dead & a laser is born

Nice build. This is an All time favorite host. Nice work.:gj:

Now for the Blinking.

It could also be your cells.

Especially if you are Stacking 1x 18650 and 1x 16340. Your just asking for it there. Thats pretty dangerous if i read correctly that is what you are doing.

I think thats your problem. There is Plenty of heatsink for that driver there. I dont think its overheating.

I think that 16340 is struggling to keep up with the 18650 and the overall build.

Try IMR 3x 16340.

 

[benmwv]

Re: 2.3W Little Fathead - a flashlight is dead & a laser is born

Cool build. I'm not a big fan of really long flashlights/lasers so I think it looks better with the piece removed

I agree that 18650 and 16340 is a bit dangerous/crazy. I bet its lower power that way because the 16340's voltage is sagging with so much current. I think you need 2x 18500's.

With 3 batteries you have about 13 watts of heat instead of about 6 watts of heat when using 2 batteries. All but about 2 watts of that is on the regulator so there is nearly 3x more heat on the regulator when you have 3 batteries instead of 2. You will need to have the regulator side heatsinked really well if you plan on using three batteries.

Two 18500's should fit perfect and be a lot safer than 18650 and 16340, and also be easier on the driver

 

[danefex]

Re: 2.3W Little Fathead - a flashlight is dead & a laser is born

Nice build. This is an All time favorite host. Nice work.:gj:

Now for the Blinking.

It could also be your cells.

Especially if you are Stacking 1x 18650 and 1x 16340. Your just asking for it there. Thats pretty dangerous if i read correctly that is what you are doing.

I think thats your problem. There is Plenty of heatsink for that driver there. I dont think its overheating.

I think that 16340 is struggling to keep up with the 18650 and the overall build.

Try IMR 3x 16340.

Thanks Angelos. Also thank all of you for the warnings about mixing the batteries. I know this is dangerous, but I confess I do a lot of dangerous things in life. It helps me get ahead sometimes & also teaches me painful lessons every now & then :crackup: Seriously though I do appreciate the caution & concern, I'm not going to use different sized batteries on this one because of the instability & because I dont want to go too easy on this 9mm 445

I'm going to pull the driver & flip it right now, I'll let you know how it turns out. Thanks again folks for yor input

Cool build. I'm not a big fan of really long flashlights/lasers so I think it looks better with the piece removed

I agree that 18650 and 16340 is a bit dangerous/crazy. I bet its lower power that way because the 16340's voltage is sagging with so much current. I think you need 2x 18500's.

With 3 batteries you have about 13 watts of heat instead of about 6 watts of heat when using 2 batteries. All but about 2 watts of that is on the regulator so there is nearly 3x more heat on the regulator when you have 3 batteries instead of 2. You will need to have the regulator side heatsinked really well if you plan on using three batteries.

Two 18500's should fit perfect and be a lot safer than 18650 and 16340, and also be easier on the driver

All of this information is very helpful because I didn't think the battery indifference was that dangerous. As I said before I thank you too for the warning & info. I wish 2 18650s would fit but unfortunately they're about an inch too long :beer:

 

[lazeerer]

Re: 2.3W Little Fathead - a flashlight is dead & a laser is born

No Problem.

Why not use 2x 18500 like Ben said. Those should fit perfect instead of 3x 16340.?

Also What part is exactly stripped in the tail cap.

I have an Extension piece for this host that iam not using. If its the piece you need its yours if you want it..

THe Extension piece i have is the size of an 18650 more or less. Its not the Short extension piece that is the size of a 16340 more or less.

SO is that the piece you would need to be able to screw on the back.?

I can take a Pic when i get home from work for you if you dont know which one iam talking about.

 

[danefex]

Re: 2.3W Little Fathead - a flashlight is dead & a laser is born

I have some 18500s on the way, I'm sorry I forgot to mention that I was going to try those also.

And the stripping, that is on the back of the 2nd half of the center piece of the host that is stripped. The tailcap is fine, it just wasn't screwing on the extension tube of the host.

It sounds like that extension tube you mention would fit this host too, but I actually like it more now that it's shorter. It feels sort of beefier now, the head looks massive this way & if I used an extension tube I'd have to change its name to the 'not so little fathead' hehe :crackup: That's nice of you to offer man but I'd like to keep this as it is as soon as I fix this driver issue....

I just flipped the driver & remounted the IC side down on the pill with adhesive, let it dry & tested it. Crappily the same thing happens, I'm using 3 16340s and it hits 2.3W & starts blinking again. Same amount of time exactly like before :thinking: Both sides of the driver are sinked, heat must not be an issue unless the IC chip is pressed too hard between the HS and the pill(?) I have pics but there's nothing special to add or share.

I also dont have another 1.8A driver to swap out right now. Looks like it's time to hit up CL for some xdrives - unless of course you have any FS :beer:

 

[danefex]

Re: 2.3W Little Fathead - a flashlight is dead & a laser is born

Just an update on this thread, this little fatty got a nice facelift tonight after 4 months of rest :eg:



:beer: