Little help needed on building Magclone thrower

Hi guys!

Currently I'm on the way building my Magclone thrower, and I call it as "Magclone" simply because I bought the light from DX and it looks like the real Mag as it is very cheap

I'm going to put XR-E R2 emitter with DX 50mm aspherical lens. I have ordered a 1.2~2.0A driver from DX, but it still havent arrived yet(as you know, DX shipping is very slow...) so I plan to direct drive the XR-E R2 first before receiving my driver with two alkaline D-cell(non rechargeable) batteries. So I wish to know that if doing in this way would be too much for the led? I have seen one of the CPF member Masha(sorry if wrong spelling...) build of MagDEFT, which has been overdriven to around 2.0A if I remember correctly.

And If Im not mistaken the data sheet stated that the safe range of ampere for R2 would be 1.0A, and I saw some examples here in CPF that some people overdrive it to 1.4A, 1.6A... something like that.

By the way, I just burnt my multimeter fuse few days ago...

Using 2 alkaline cells to drive a white LED should get it to light up, but not very brightly. The forward voltage of the LED will be high enough that you will likely be driving it at less than 100mA if you only use 2 cells.

Thanks for the reply

Using 2 alkaline cells can only drive it to less than 100mA? Then what should I do to increase the current? By changing it into 18650 cells, or can I install the 1.2A driver and still using the alkaline cell?

Thank you.

If two alkaline D's are your power supply, you'll need a boost driver to bring the voltage up to necessary levels. Try using two or three of these in parallel. I have recently built a light using two in parallel that were also modified by doubling up the sense resistors from two others, to bring the regulated current output up even higher. (Don't do that without great heatsinking though.) To wire in parallel, simply install the second with all the same connections as the first.

Direct drive from alkaline batteries? why?

Thanks for the advice, guys

I wish to direct drive the R2 because I want more power out of it, and this project also some kind of experiment to me. I own several LED flashlights but I am new to flashlight mods. However with two alkaline batteries it seems that both the voltage and current is not enough as Techjunkie said.

By the way, I have tried using two alkaline D size batteries to direct drive the R2, and the throw is weak... with DX 66mm aspheric lens it throws just slightly more than 200 meters with the measurement from Google Earth.

I plan to change into direct driving it with Li-ion batteries, however 32650 or 26650 seems very difficult to get in my country, so I wish to use two 14500 Li-ion in series(with A to D size converter) to direct drive the R2. So what do you think guys? And any idea of increasing the throw? Thank you.

What size is the "Mag"? 2D? I really enjoy running 3 x NiMH in my 2D mags using adapters and spacers. I also use a 7135-based driver with 3-cells, as well as do some custom programming on the driver micro-controller as well. Makes for an inexpensive, safe, and user-friendly setup.

bibihang said:

Thanks for the advice, guys

I wish to direct drive the R2 because I want more power out of it, and this project also some kind of experiment to me. I own several LED flashlights but I am new to flashlight mods. However with two alkaline batteries it seems that both the voltage and current is not enough as Techjunkie said.

By the way, I have tried using two alkaline D size batteries to direct drive the R2, and the throw is weak... with DX 66mm aspheric lens it throws just slightly more than 200 meters with the measurement from Google Earth.

I plan to change into direct driving it with Li-ion batteries, however 32650 or 26650 seems very difficult to get in my country, so I wish to use two 14500 Li-ion in series(with A to D size converter) to direct drive the R2. So what do you think guys? And any idea of increasing the throw? Thank you.

Click to expand...

Two Li-Ion in series will push waaaaay too much voltage to the LED and you'll kill it. You can direct drive one LED only from a battery pack that has voltage under load equal or less than the forward voltage of the LED at max safe/desired current. For almost all white high power LED's that's either one 3.6V or 3.7V Li-Ion battery or 3x1.2V NiMH batteries.

JonnyC, my "Mag" is 2D. Soldering wires on the driver already drive me crazy, somemore without the proper mounting for the driver which I dont know where should I mount my driver on, and this is one of the reason that I wish to direct drive my led is because my "Mag" does not has aluminium heatsink which suits for the led and driver. One of the CPF member does sell H22A heatsink for Mag if I remember correctly, and that heatsink is awesome but it is too expensive for me, especially after adding the shipping fees

Techjunkie, oh ya I was just figured that out too. According to Cree datasheet the maximum forward voltage would be 3.7V, and using two li-ion in series will give about 7.4V in total!!:O(assuming each cell gives 3.7V) So you are completely correctly.


My plan now is using just one 14500 cell in a A to D cell adapter, and hardwired the other A to D cell adapter(I need two A to D adapters because this is a 2D "Mag", but since i will only use one 14500 so another adapter would be "empty", and hardwiring it is needed.) So may I know if I do in this way would the R2 achieve much higher brightness than powered with two alkaline D cells? Both are direct driving by the way.

Please guys I need your advice very much as I almost finish my 'unorthodox' project. My aspheric lens installation are OK already and now I only left the problem with my R2 brightness which I'm still struggling with. Maybe I will upload some photos of my light after it is successfully finished

I recently jerry rigged a drill press light with stuff laying around the house using an xm-l, a laptop cell, switch, a computer southbridge heatsink, and a 1.5 ohm resistor to keep voltage in check with the led.

How I figured what resistor to use if you wanted to use a resistor is by this simple formula...

V battery cell - V led forward voltage, then divide by current amperage

So...

4.2(2) - 3 = 5.4

Then you divde 5.4 by 3

5.4/3 = 1.8 ohms

Closest resistor is 1.5 ohms. It's pretty bright and about on par with my xm-l mini mag. Only problem is the resistor gets stupid hot when you use two cell, so I use just one cell. Not as brightbut the resistor doesn't get hot....