PT Yukon "Mule" mod

I've had a gutted Yukon sitting around for over a year, so I decided to finally do something with it:



That's a Cree XP-G R4 neutral, on a 1 1/4" aluminum disc epoxied to the body of the Yukon. There's a AMC7135 350mA driver on the back of the heatsink. I made it only one level, but it'd be super-easy to make it a two-level light, all you'd need is another driver or resistor (because the Yukon already has a double throw switch). I should get decent runtime off of 3xAA Eneloop, so I wasn't worried about a lower level.

The light is, as you can imagine, a beautiful warm flood. Output should be a bit over 100 lumens. (edit: I just did the math - output should be 110-120 lumens, considering the plastic lens and the small amount of light lost to the sides of the bezel.)

Bolster: With the light held 1' from the wall, the beam is 8' wide

Re: Pt Yukon "Mule" mod

sweet.

Re: Pt Yukon "Mule" mod

Finished the runtime test... On 3xAA Eneloop, the light dropped out of regulation at 5:30, and went dark at 7:15.

Re: Pt Yukon "Mule" mod

thought i'd contribute a pic of my revised River Rock 2AAA mule. it's the same mod that i wrote up in another thread, but this is actually another headlamp i had around. used an XR-E Q2 on this one. XR-E because the data sheet seems to say that XR-E's are brighter on lower currents than XP-G's. and Q2 because i was determined to not spend more on the LED than i did on the headlamp itself, although, in retrospect, i probably should have just spent the extra couple bucks and gotten an R2. lo beam is more useful than my original Lux I mule as i can actually read with it comfortably now. output on hi should be around 25 lumens. and my favorite part - total weight w/ batteries is 2.5 oz.
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Note: I noticed that Glad Press'n Seal over a bare emitter like this doesn't give off the elliptical hotspot effect that it does with reflectored beams - just soft flood with a smooth transition at the edge of the beam.

Edit (6/22): the final version w/ XP-G R4 4B on a copper penny heatsink w/ Press'n Seal diffusion.
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Re: Pt Yukon "Mule" mod

Nice, I'll bet that River Rock mule is really useful around the house.

I took my modded Yukon while exploring an abandoned mine the other day. I never had to worry about where I was stepping, because the ground around me was lit up nicely (good!). On the other hand, I couldn't see more than 30' in front of me (bad!). I ended up using my handheld light constantly, for navigating large rooms and the long tunnels. It may work better for caving, where fewer passages are in long straight lines.

Re: Pt Yukon "Mule" mod

vtunderground said:

Nice, I'll bet that River Rock mule is really useful around the house.

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yep. i use it daily and i really like it. it's like a cheap Zebra H501 w/o the high mode. i haven't been able to stop tinkering with it though, and now i have an xp-g r4 4b on the way.

vtunderground said:

I took my modded Yukon while exploring an abandoned mine the other day. I never had to worry about where I was stepping, because the ground around me was lit up nicely (good!). On the other hand, I couldn't see more than 30' in front of me (bad!). I ended up using my handheld light constantly, for navigating large rooms and the long tunnels. It may work better for caving, where fewer passages are in long straight lines.

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i ran into the same problem with the Duracell 3AA mule i'm working on (which is a project inspired by your post) - 20' hemisphere of illumination and total darkness beyond. i'm gonna try mounting it chest high and wearing an Eos on my head at the same time and see how that works.

Robostudent5000 why not use the reflector/optic or whatever originally came with the Yukon and then just using tape over that. Would that give you the added distance that you're looking for? Or does it change the flood nature of the beam that you desire too much?

Interesting detail about the Press n Seal that I didn't know about (not elliptical directly over the emitter)!

gcbryan said:

why not use the reflector/optic or whatever originally came with the Yukon and then just using tape over that.

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The Yukon originally had an incan bulb My original plan was to modify the stock Yukon reflector to work with a high-flux LED, but I decided that a pure flood light would be a fun experiment.

vtunderground said:

The Yukon originally had an incan bulb My original plan was to modify the stock Yukon reflector to work with a high-flux LED, but I decided that a pure flood light would be a fun experiment.

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Ah! I'm sure it is a fun experiment too I also agree that a pure flood beam is generally more pleasing to the eye (or at least different) than a diffused spot.

I wish I could solder better and was better with electronics! I'd quit complaining or looking for the perfect headlamp and just mod something the way I would like it to be!

gcbryan said:

Robostudent5000 why not use the reflector/optic or whatever originally came with the Yukon and then just using tape over that. Would that give you the added distance that you're looking for? Or does it change the flood nature of the beam that you desire too much?

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regarding a Yukon, i'll have to defer the question to vtunderground because i don't have one.

for the mules that i do have - a couple of River Rocks and a Duracell 3AA - i actually did try them with the reflector and scotch tape and also with 2 layers of Press n Seal, but the hotspot was still too defined and the overall beam angle was still too narrow. i think, in order achieve the effect i want with a reflector + diffuser combo, i'd need a pretty heavy diffuser, but i'm not looking for the diminished output that would cause. however, there are optics i guess i could try. i've seen some 20mm frosted optics rated at 90 degrees and higher and there's more than enough room in the Duracell 3AA to remove the reflector and squeeze one of those in. i'm hesitant to try... but still haven't ruled that out.

Edit: oops. didn't see the last two posts.

Thanks for the remarks Robostudent. The confusion was caused by me. I referred to the Yukon while reading your post. It was directed at you.

I get your point regarding the diffuser tape and the reduced light output it would probably cause by the time the beam angle opened up more.

I had a plastic diffusion filter from an old dive light that I recently cut a circle out of and used it in a P60 XP-G drop-in flashlight and it created a great flood but it probably did reduce the lumen output. Hard to tell since a XP-G at 1.4 Amp is pretty bright under any circumstances.

I used tape on my headlamps spot beam and it did what I wanted it to do but it's not a true flood beam (didn't matter in my case as the headlamp already has one of those as well).

I guess (in your case) it's hard to get the wide flood beam and increase the throw beyond what it current is.

pics of a Xp-g mule mod of the Duracell 3AA. used a xp-g r4 4b. pleasant, vanilla tint. also, cut off all the unnecessary parts and added new headband. overall, very useful as a work light.

press n seal on the lens smooths the edge of the beam.
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with bezel off - xpg on copper spacer thermal taped to the sink. yup, the spacer is a sanded 1981 penny.
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