Convoy C8 triple with Kiriba machined head

Kiriba-ru sent me his finned C8 triple head for testing.

I’m a big fan of the unique look in the sea of boring triples so I was happy to take apart my clear Convoy C8, which I barely use anyway after getting the D1S.

Installing the head is a piece of cake. For $45 Kiriba includes all the needed parts except for the triple MCPCB and driver, and the C8 of course. A 20 mm driver fits right in the head and there’s a retaining ring to lock it in place. He even includes a drill bit for making a hole in the middle of the XP32 MCPCB. If you’re not experienced in reflowing emitters yourself, mtnelectronics can do it for you. I took apart another build since I broke the Ledil optics Kiriba sent me… from the same light I salvaged the Noctigon XP32 board populated with the great 219C 5000K CRI80 emitters. The beam is smooth and the tint is beautifully neutral.

There’s three o-rings. The green glow in the dark one fits between the ledil triple optics and glass lens (there’s a small indent between the head and the optics). One of the black ones goes between the lens and bezel and the other one between the head and the bezel at the lower part of the threads. There should be no way of water getting inside.

The aluminum head naturally weighs much less than an X6 head with Kiriba’s huge copper spacer, but the large fins should help when there’s some airflow. Less thermal interfaces is also a good thing: the MCPCB is in direct contact with the head. The C8 weighs 157 grams and the X6 almost double at 301 grams without a battery. Unfortunately I don’t have a direct comparison since I’m using 219B CRI90 emitters in my X6 with a Dr. Jones H17F driver. So take the output and runtimes as they are.

I did set the temperature limits to similar levels, so both will begin stepping down when the light gets too hot to handle (about 50-55°C). The H17F is much more sophisticated though with a real PID control whereas the MTN-17DDm uses Bistro with harsher stepdowns when the limit has been reached. It keeps decreasing output if the temperature hasn’t dropped enough during the last 10 seconds or so.

I used a protected Acebeam high current battery which comes with the X45. Its internal resistance is very low and current limit high enough for this build not to trip it. The C8 had the default tailcap spring without bypass, X6 has double springs. The driver on the C8 is bypassed while the H17F driver on the X6 isn’t. The initial output is comparable with the 219B X6 being about 6 percent lower. This would indicate a lower resistance current path for the X6, since the difference would be higher if anything else was equal. The different drivers also play a part in this of course.

When the lights are on maximum output without any external cooling, the graceful temperature control and higher mass of the X6 + H17F performs better. The Bistro driver on the C8 keeps going down all the way to 20 lumens and doesn’t recover on its own. You can reset the output manually of course.

If we add a low speed fan to circulate airflow, the huge fins on the C8 do a marvellous job. It doesn’t step down at all but follows the battery voltage. A boost driver would be ideal to take advantage of the great cooling performance.

Here’s the first 5 minutes zoomed in.

Regardless of the great performance of the head, the thing that makes it for me is the clean look and the fact it matches the clear Convoy finish so perfectly.

You can order the head and parts from Kiriba’s thread here: Low-cost copper pills, spacers, optics, drop-ins (Updated 23/10/2022))

what a beautiful design, great work by Kiriba-ru

I like it. Functional design that takes advantage of the extra room provided by the lower height of the optics.

Very nice Maukka, the anodizing of the clear C8 is a great match for the head. I started with a black Sofirn C8 as host it turned out like this :

My setup is almost identical to yours : Nichia 219C D240 4000K 90+ CRI emitters and a MTN-20DDm FET + 7135 Driver with Bistro

Nice!
For aestetics the light needs a custom tailcap too, with a couple of shallow fins spaced the same as the head, instead of its ‘C8’ styling.

Looks like a winner design :crown:

It looks like its ready for an episode of Dr Who. Well done all involved. :beer:

Wow. That’s outstanding! Great job Kiriba-ru!

I’m adding one to my short list immediately! Love the futuristic “Ray-Gun” style!

Kinda cool, but I don’t like the bottom part of the head at all. It looks really out of place with the small body of a C8… That being said, I’ll probably order one myself but intend to dremel the size of the bottom ring to about half of its current diameter.

Yeah I guess that would seem better, or the bottom 3 progressively smaller towards the bottom. But OTOH it’s very unique the way it is!

Beam shots? :sunglasses:

Maukka, is the X6 weighing 301g with Kiriba-ru’s copper spacer?

Yes.