Budget headlamp setup...beginner needs some second opinions.

Hah….I just ordered an extra switch for that reason! Funny how that works.

Anyways, thanks for the info. I am looking forward to getting this up and running.

I have already ordered everything, but just to make myself angry, how would you achieve a similar setup (using AA nimh batteries and 2 XMLs)?

I would probably power it from 4 eneloops (around 6 volts at full charge) using a E1320 7135 driver. It is a driver that a member here(E1320) buys and reprograms so they have 5 modes going from moonlight to 3.1 amps. Then just repeat for the second XM-L.

Or if I got adventurous I might try to make one of the QTC variable output ones. QTC is a material that when pressure is applied conducts electricity, and more pressure is more conductive. With that it can be infinitely variable. What your are doing definitely has potential and sounds like a fun mod.

Very cool. Well hopefully this doesn’t turn out to be a complete fail! Hehe. If I can get 1000-1500 lumens out of it and 2 hours of runtime, I am sold. You think that is possible?

Interesting project! but this is SO far above my comfort level pay grade....I have nothing to add....but will watch the thread.

Yeah that sounds like a fairly realistic goal. What are your plans on heatsinking them? And what about optics? I'm guessing one flood one throw?

@Gnarly, why don't you try modding something. It isn't that hard to make a P60 drop in. :)

yObailey had the switchs on the +, scaru has them on the -.

Does it make a difference ?

I bought several optics with various beam widths to see what I like best. Basically mix and match until pleased. They were $1 a piece, so I splurged a bit here.

I have tons of computer heatsinks around, so the LEDs will be very well cooled. I run a more “wide open” design so they get plenty of airflow.

The drivers themselves I worry about slightly, but I will probably find bits of aluminum and epoxy em on to be safe. I am hoping I have the newer revision of the drivers, which seem to overheat less frequently.

Shouldn’t matter. The switch basically just closes the circuit to allow electricity to move through (think of it like cutting the wire). If you cut the wire on either + or -, things still shut off. If you reconnect it, things turn back on.

That would be my uneducated guess.

It's a pleasure to know you, y0bailey!

I built a double XML headlamp thingy for my helmet a while back but, eventually took it apart because the heatsink, reflectors etc, were a bit heavy and cumbersome. If ambient temperature is low and you’ll be going fast enough on high mode, then, you may not need something that stresses your neck. I wish you luck with the build!

You guys were right it shouldn't matter which side the switches are on.

Newest plan thanks to some ideas here and at another forum. Basically adding dual switches like scaru suggested, and slightly changing the wiring to make sure that both batteries drain equally, even if one light is completely switched off.

This prevents the drivers from getting out of sync (meaning one is on medium, on on high, and being unable to get them back to the correct mode simultaneously), and allows even more adjustability. Aka I can cycle and have both on high, on high one medium, both medium, one off one on, etc.

Does this look correct to you folks!?

These parts cannot get here fast enough!

Seems right to me.

Oops. Not sure how I missed this. Looks like it should work. I'm guessing the white lines are not wires or anything? Make sure you wire it up to test it before you do final assembly though.

scaru, the white lines were where the original parallel connections were.
y0bailey, the drivers I used were different from what you’re using however, I got ‘interference’ when both drivers were on ie, there was NOTICABLE flickering on low and medium modes. With one driver/LED was on, there was no flicker. Not saying it’s going to happen but just letting you know it possibly can.

Barely can INSTALL one, let alone: make one!

If I did, it would be as big as a haybale. And use a Farmall headlight.

Thanx for the encouragement....I'll just hang here & try to learn.

Sorry, late to the party. This looks much like one of my first mods. I think the driver is a clone of the KD Super output P7 driver. Mine is still going strong after 3 years. I used it to power 3 xreQ5’s in parallel from 14 nimh cells 7s2p. I found that with 5 or 6 cells the low voltage warning would cut in before the cells were actually low. The build thread is on mtbr under same Rufusbduck. I used vistalite nightstick bits for lamp housings, wire, switches, batteries, holders, just about everything but the bulbs. Swapped the original subc cells for new 4/5 subc to get 7 in the space of 5. I like your idea for 2 drivers/switches. The drivers are not great for efficiency especially on lower modes. I think Subjohan at CPF did some testing with them. See this thread. Others have found them to be of inconsistent quality which is not surprising for a buck driver that inexpensive. Do what you can to avoid the driver sharing heat with the led as the driver has a thermal cutout. I know they do work but some people have had issues. Good luck

Yea. I am thinking that in order to avoid the lower efficiency medium mode (I will never use low), I will just turn one off one on, for around 1000 lumens. That might be the realistic sweet spot, and I should get 3-4ish hours of runtime in that mode.

Did you heatsink the drivers at all? I am trying to find some good methods, and wondering if you had suggestions.

Yes I heat sinked the drivers. the CPF thread I linked above has a few different methods in it. The inductor and fet both get warm. Whether you use cu or Alu, get it as close to those two parts as possible(ideally touching with a thin layer of AA) without shorting any pins/wires and then pot it with fujik to keep the wire leads from breaking off. I built up layers of cu sheet to the height of the inductor, added another piece on top and potted it in 3/4” cu tubing ~1/2” long. The layered pieces were soldered together and AA’d to the tube which was then AA’d to the housing. The LEDs were mounted to a separate heat sink to avoid heat pollution of the driver. I’m out of the house today but later I can post some pics of another build that uses this driver( the “dog-walking” light).