DBC-05 Triple XHP-50.2 Scratch Build !NOW XHP-70.2!

As is the case so many times there were a couple of reports of new stuff here that I just had to try! :slight_smile: djozz reviewed the new XHP-50.2 and TexasLumens was looking at the 20700 cells, so I figured I’d build a light and try both of those at once. This is my 5th full build from scratch, hence the name, and while I’m still on the learning curve with the lathe I think it’s working out pretty well.

Initially I made a battery tube from thick walled 6061 Pipe that would easily hold the 20700 with room for the 21700 when those become available. Getting the light completed to a fair simile of the design showed me that I needed to make some changes.

Here’s the design…

I don’t have autocad abilities so this is mocked up in Photoshop to scale.

I ordered the materials, including a 3.17 pound chunk of Tellurium Copper for the head. First draft, getting the knurling on the tube and getting the copper semi sized to fit the triple reflector from KaiDomain. Since I didn’t have the reflector and emitters I wanted to just get it close first, to save some time later when the other parts arrived…


As you can see, I was trying to utilize some pieces I already had here, so I mated the larger diameter aluminum bar stock to the top of the Te/Cu to accept the 63.7mm reflector. ( the Te/Cu was the largest diameter piece I found at my supplier online)

Then I did about 90% of the stock removal in the copper for the big reflector…

So, I’m really bad about finishing a project in one continuous process so I don’t forget what I’m doing, but in this case the above parts were set aside and I had to wait a couple of weeks for parts to arrive. A lot went on in the meantime, including a 1600 mile trip out of state to shoot photo’s of my nephew’s wedding. When we got home, parts had arrived! I jumped right on the light, (they were on their honeymoon, figured they had other things to worry over than pictures!!)

And this is the initial result…

The triple XHP-50.2’s made numbers like this with the 20700B (the high capacity version of the Sanyo cell, the A variant wasn’t available)

0.18A for 122.13 lumens
0.42A for 333.96
1.22A for 941.85
4.67A for 2839.35
9.01A for 5147.46
15.25A for 7866
with a 30 sec showing of 7728 lumens

I then bypassed the spring on the driver and got it up to 20.34A and 9108 lumens. Still a long ways from what I had though this new emitter might do.

So I machined a copper spacer to act as switch retaining ring and got it up to 10,488 lumens with a 30 sec showing of 10,005 lumens

Hmmmm, still not there. So I tried a pair of Sony VTC6 cells. These showed me 21.12A and made 11,695.6 lumens. Better! Of course they fall like a ton of bricks, so I decided to rebuild it.

The piece of 3” pipe I used to make the bezel, initially, left very little shelf for the lens to seat against. Figured to make a new bezel and a 26650 battery tube…

So now, with a thicker walled and nearly exact external diameter 6061 pipe I was able to get a nice wide shelf for the lens and put an o-ring groove into the face of the shelf. So the lens is sealed up top. This is an UCLp lens from flashlightlens.com

You can make out the o-ring at the lens in this side angle shot. The bevel on the bezel is the same angle I used everywhere there was a bevel, this is the angle the reflector required to mate up in the head.

In this next shot you can see how I sleeved the bezel to allow a difference in lens thickness, the UCLp is 2.25mm thick but a lot of good glass out there is 3mm or more, so I allowed for a few mm of play in case I wanted to change lenses later.

The 3 XHP-50.2’s in the KaiDomain reflector

The overall modified light with it’s 26650 battery tube… I’m not good at knurling. I know there are diameters that work well with a given tool and there are diameters that do not. For the first time I tried using the feed on the lathe and started the knurling tool at a fairly deep set. This resulted in a tight spiral groove with the opposing steps stacked and killing the diamond pattern. It feels good in hand, doesn’t look bad unless you look really close, but it is what it is…

Since I had already done a lot of work on the tail cap with the smaller tube and had some copper invested in it, I decided to salvage the switch mechanism and copper of that previous version. To do this, I simply cut threads right into the knurled tube! Using it as a plug to thread into the larger tube and cutting a matching ramp in the opening of the bigger tube allowed it to work. Makeshift, perhaps, but it works. :stuck_out_tongue:



So now it takes 26650 cells, waiting on some new LiitoKala 5000mAh 26650’s to arrive from GearBest.

Initial look at a pair of Basen’s shows me 11,247 lumens. Still in the ball park with more capacity.

Hope to get some beamshots tonight but it’s been raining so it might be later in the weekend.

Thanks for cheking it out! Lot of work in building a light, probably have 20 hours in this what with a couple of screw-ups on my part. And so the learning curve continues…

Edit: Beamshots added 3-26-17

This is from the same ol Canon G1X camera, 4 times faster shutter… ISO 1600 at F/5.8 with 1/8 second shutter in Manual mode on the tripod. First is 28mm equivalent, second is 112mm equivalent or 4X.

The red 55gal oil drum is at 97 yds, spring is fully upon us so everything’s getting bushy! lol

Great build! It takes a Dale to be not completely happy with 11K lumen! :smiley:

I’m looking forward to the Liitokala cell results!

Looks nice :+1:

Crazy isn’t it? I had no real idea what 3 of those emitters would be capable of, but had it in mind they should easily do 15,000 if not 20,000 lumens. So, well you know, you put in the time and you want RESULTS! lol

They could gobble up 30A, sure they could, but finding the pair of cells to give it to them is another matter altogether.

Oh, by the way, it weighs 2.61 lbs (1184 grams) with 2 Efest purple 3500mAh 26650’s inside. :wink:

Thanks for the build thread Dale. Your light is a real winner and looks amazing. Keep up the excellent (machining) work. :slight_smile:

Very nice. I like the look of the head.

I wish I could knurl em like you do my friend, maybe some day…

Wow Dale, that looks great… God I really want a lathe, going to look at an Atlas Heavy 10 with collets, good adjustable 3 and 4 jaw heads and a multi-tool holder this weekend. The fella also has a very clean Bridgeport knee mill with DRO and all are set up for single phase operation.

These look like they’d power that light nicely:

HKJ actually melted his battery holder before the cell’s amperage was maxed out!

So where can I find those? I wanna melt something! :smiley:

Well just awesome!
so cool these really build from stock bars projects, but so far out of reach for us mere mortals :wink:

Couple of years ago I was bolting bar stock to my drill and using a rotary tool to cut out what I wanted. Now I use the 10x22 lathe in much the same manner. lol
All Professionals are trained amateurs. Everybody starts somewhere, me? I just have to keep starting with my horrid memory…

I make my share of mistakes, like when I was making this simple spacer with one step to go between the retaining ring and pcb of the switch… in that last split second when you expect the part to fall in your hand it does the unexpected and flips over, jamming the lathe to a complete stop and mangling the last 30 minutes of careful work. And so it goes…

Looks sweet pal! More like a piece of art than a torch.

Shame you cant buy many unorthodox designs (i’d love to turn one but i don’t have access to the equipment)

Gorgeous job once again Dale!! You need those SAM 21700's. Can you make be a 3Px2S 21700 battery tube for my 16X?

Wow this has to be my fav of all your scratch builds. The looks is just awesome. You really gone a long ways, I can totally see the improvements in design and total build.
Keep up the great work!

Ahh beautiful, making me really want one of your customs!

Tom, that’s something I have yet to learn. Offset turning. I have the 6” 4 jaw chuck and the offset plate but don’t know how to set it all up. Figured I’d get there one of these days but haven’t so far. Maybe MRsDNF will take another vacay and swing by and show me how all that works. :wink: I could of course run up to North-West Texas and get Dan to walk me through all that.

Its not as hard using a four jaw chuck as it seems Dale. Some marking out and a centre pop where the centre of the hole is. With a centre in the tailstock run it up to the work piece and adjust the jaws until your centre pop mark is central to the centre in the tailstock.

We have all watched what you can do dale and I have 100% faith in your abilities to be able to do this. You are a natural. :+1:

Super nice work Dale!! Thanks for sharing the build. TL