The  XHP35 HI Epic

I’m _still_ in the midst of an epic modding journey.

It started earlier this year. I’d picked up a Convoy L2 with an XP-L HI for a bargain price (like $25) from a Banggood deal. I was really impressed with it when it arrived, and I was eager to try it out when night fell.

When night came, early as it does in winter, just below the 48th parallel, I loaded up some freshly charged cells, grabbed my Sofirn C8A for comparison, and headed out into my front yard. I turned the L2 on. It came up in low. The hotspot on the pavement in front of me was certainly “hot.” I fired up the C8. The contrast in the contrast (yeah, I just wrote that, and I’m leaving it, so…) in brightness between spill and hotspot between the two was stark. The L2 was clearly primed for throwy greatness.

Next step, to see what it was really capable of. It took me a minute to get used to the forward clicky switch and into high mode. Honestly, I was a bit underwhelmed. I don’t know what I expected, but in retrospect, I realize I’d only have been satisfied, only avoided this woeful journey if I could light a spot on the low-hanging clouds overhead.

Perhaps, I couldn’t see it because too much light was being thrown back at me from the moisture in the sodden Seattle winter sky? Maybe I just needed a little distance? I propped the light up, and started backing away, down the sidewalk, eyes upward. As I did, I could see the shaft of light thrusting into the night. I could also see that it dissipated in the mist, before reaching the low, heavy, smothering blanket of clouds.

My head dropped, my eyes on the damp, dark, sidewalk as I plodded back to collect my flashlight and then up my front walk. The weight of disappointment was almost too much to bare as I climbed the steps to my front door. Inside, I was sullen as I unscrewed the tailcap and let the heavy 26650 cells slide out, one by one, into my hand. I placed them on the shelf, reassembled the light, and set it, face down, at the back of the shelf.

I was restless for the remainder of the evening.  It’s clear to me now, but at the time, I didn’t recognize the obsession that was already growing within me. I’d needed something to look forward to, some bright spot to look forward to in the midst of another dim, damp, northern winter. I hadn’t had the money to take a week’s holiday in warmer, sunnier climes. I needed a flashlight, one that could cut into the oppressive winter, a light that would light my way along the long, slow path into spring.

It was only about six months ago. I was not young then. It was just six months in a life fast approaching its fifth decade. I was not inexperienced, but It seems so long ago, now. How far I’ve come; how far I still have to go.

I was restless that night, as I’ve said. That night, in the depths of winter, in the pit of my disappointment, it would have been the easiest thing just to surrender, to drag myself to bed, and sink back, deeper, into the hibernating fog of a Seattle winter. But, instead, the spark of hope and found dry tinder, perhaps in hidden memory of a warm september. The tinder had flared, and lit an ember, and its warmth melted something in me.

This cool drop shivered through me, rousing me. Before I slept, I started to plan. I was so naive. I thought I could reach those clouds. I thought I could, with my meager means and knowledge, send a shaft of light into the clouds that separated me from the clear sky, from the moon, and sun and stars above. If I’d known then the path before me, I’d never have taken one step on it. If I’d known how my journey would stretch through winter, through spring, and well into summer, I would have saved my resources, conserved my strength, and waited for the sun to cut through the clouds again and reach me.

But, I was a fool then, as I am now, in the middle of summer, the sun bright and high in the sky, while I trudge forward, still, eyes down. I started this journey because I didn’t know better. Almost from the start, the path was not an easy one. I stumbled, slipped, tripped, and fell. Each time I dragged myself up, I could have turned back, or simply rested until the sun reached me, but, always the fool, I rose and turned myself to face the uncertain path in front of me. If I knew then, what I know now, I would be outside now, in the middle of summer, the sun bright and high in the sky. Instead, I press on an unknown path, towards what, I suspect, is an unreachable goal

Back then, fired by false hope, I launched myself on untested wings of feathers and wax. I would build a new light to eclipse the disappointment of my L2. I would preserve the L2, and test it against my new creation, and let the contrast reveal what I was capable of. I was, as I’ve said, a fool. And like a fool, rather than turning back from bad decisions, I instead committed myself to them

I wanted a host which, like the L2, could be used with either one or two cells, but I didn’t buy another L2. I wanted an emitter capable of more output than the XP-L HI, but I didn’t want to dedome something, and I didn’t give sufficient consideration to luminous intensity.

For the host, I chose one of the few inexpensive convertible 26650 hosts I could find. It’s reflector had a smaller diameter than the L2s. It took an eternity to reach me.

For the emitter, I chose and ordered an XHP35 HI. When I started to understand it’s limitations, I didn’t reconsider my choices. I didn’t look for a lower voltage emitter that would offer a greater choice of (more powerful) drivers. Instead, I ordered the only 1-2s capable 12v boost driver I could find (H2-C), even though I knew it would need modification to drive the emitter harder, even though I knew the emitter quickly hit a point of diminishing returns when overdriven.

When all the parts finally arrived. I looked them over. The cheap host was definitely cheap, with poor machining, rough thin threads, and terrible thermal path, but I had it, and I liked the look of it. I cleaned up the burrs on the threads. I knocked out the thin aluminum shelf in the aluminum pill and fitted a copper and solder plug. I used thermal paste on the pill threads, and made a copper collar to try and improve thermal transfer.

I bypassed the tail and driver springs, and assembled the light. I had to kludge to get the 3535 centering rings I had to work with the ~1cm opening in the reflector. When I loaded batteries, and clicked the switch, light came out. That night, when I tested it against the L2, my expectations were low. In the intervening month, I’d learned enough to know that my choices were not going to deliver what I’d first hoped for. But I’d assembled the light anyway, because the parts were already paid for.

I did take some satisfaction with what I’d done. For $30, I had a light with a nice warm, white tint, that threw about as well as my L2, but with a larger hotspot. I could have stopped there.

I might have stopped there, if only I’d stepped back and considered what I’d done, if only I’d taken the time to notice that the days had grown longer, the clouds higher, and thinner. I should have stopped there. I couldn’t stop there. I knew I could do better with what I already had. I knew it wouldn’t be enough to cut into the low clouds in the depth of winter, but I couldn’t move on, and I couldn’t put it down.

I’d mod the driver to push the emitter harder. It wouldn’t get me where I wanted to go, but I could do it, I would do it. If, in the long run, it ended up burning out the driver or the emitter, so what? It already fell short.

If only I’d been content to stop there. I wasn’t. Before modding the driver, I set about modding the host. I’d ditch the aluminum pill, which screwed into the body tube. Instead, I’d fabricate a copper pill, and fit it firmly, snugly and permanently into the head.

I didn’t have a lathe, or even a copper rod. I did have saws, files, copper plumbing pipe, copper wire, and solder, and I decided to make do with what I had. It exhausts me to recall everything I did. I just know that it took a couple of weeks of tinkering before I had something I could reassemble into a light, which I did.

It didn’t work. After all that work, I’d managed to short the driver out against the reflector. The driver was dead, $10 wasted. The switch was melted. I could have stopped there, I should have stopped there. I didn’t stop there.

I had a 12v emitter, and nothing to drive it, so I ordered another H2-A driver, and another, just in case. I ordered parts to repair the switch. The order with the driver hung in limbo for a month. By the time it arrived, spring was underway. My motivation had dissipated, and I was in the middle of another build/mod (A triple SST-40 in, ultimately, an F13 host). Over the remainder of spring, and at the bloom of summer, the new and old parts sat unused. In that time, the complications of the already complicated F13 build grew, then ground to a halt, broke loose, and halted again. I had other builds too that were in limbo, waiting for decisions, or parts.

I pushed forward whatever I could, until I was stuck waiting, and restless. I turned my attention back to the thrower, sitting in pieces, scattered, the emitter in a box of other emitters. The new drivers nested in another box, among other drivers, including the original driver, which was waiting to be repaired. The host was on a shelf, the switch parts loose in the battery tube.

On Monday night, of this past week, I returned to the task. I am still not done.

I started this thread for us all to share our disappointments and failures, and maybe stories redemption. I started what I meant to be a short introduction, a summary of my own, earlier, struggles, before sharing my frustrations of the past week. I have written much, probably too much. I am still not done.

I hope you all will start. I may finish my tale yet.