First of all, I would like to apologize for my inconsiderate and ignorant content in this post. All my posts are like that on BudgetLightForum. I don’t like people telling me that, so I am putting on the table up front.
OBJECTIVE OF THIS POST
The objective of this post is to provide information that will prompt some people to share knowledge with me about building C8 flashlights.
I want to build 5 convoy c 8 lights. I want to do it for the experience. My problem I don’t know where or what parts to order. I know I need 5 c8 bodies from Convoy. I can find those I think.
How I Use These Lights
My problem is not knowing what to put in them. I know I need driver boards with leds and other elements on them. I know almost nothing about flashlight circuits. The main thing I know is some rob power from batteries and some don’t . I want the kind that does not rob power., running along the lines of direct drive when in bright mode.
I don’t want to assemble the circuits if I can help it. I want to buy them and install them, unless that is not available.
SST40 seems like good leds. I like around 5000K to get a bright light with CRI that is good to me.
For batteries, I have quite a few decent spares around. When I buy 18650s for flashlights, i usually get Molicel P28A 18650 2800mAh 35A Battery or Samsung 35s.
I like the C8s to run moonlight on one click start. 2nd click gives medium, 3rd click gives brighter. 4th click is full power. I like to disable flashing on these lights. No ramping on C8 if I can avoid it.
Are instructions available on what parts to buy and how to assemble them? Can you write what i can do, what my options are, pifalls to avoid?
I have a good soldier station.
Any information you can provide will be much appreciated.
@INeedMoreLumens gave some great advice already but I’ll add-on a couple thoughts.
You won’t need to worry about that with the C8. It uses a mechanical switch that completely cuts power from the battery when off.
I echo the recommendation for SFT40 (or probably SFT25 but I haven’t tried Convoy’s stock yet) in 5000K. It isn’t high cri but the tint is nice - no unpleasant green tint or tint shift (varied tints throughout the beam).
But… if you want to do this for experience and you’re planning on five lights, would you like the LEDs to be different so you can see what effect the variableshave? You could get some with a 6V emitter or a 12V, different color temps, floody vs throwy, etc. Depending on the LED(s) you choose you may need a variety of drivers. We can help you sort that out.
You will also need some thermal compound to go between the MCPCB and “shelf” in the light body. AFAIK Convoy doesn’t sell it. If you’re in the US, I like to buy it from mtnelectronics. If you’re not in the US, you can at least see the options. I just use the Arctic Ceramique 2.
Don’t you guys think that with a reflector this big, SFT-25R has no advantage over SFT40 ?
I mean at 8A SFT40 outputs decently larger amount of lumens and within C8 host the focusing is no longer an issue.
The 7mm hole option is good for both the SFT40 and the SFT25R. The C8+ should come with a 7mm 5050 gasket which will work with the SFT40.
For the SFT25R you’ll need a 7mm 3535 gasket.
I’m not 100% sure the host comes with one, so you can purchase them here:
According to tests by koef3, we’re looking at 2521 vs 2007 lumens at 8A, and 4.02 vs 2.25 mm^2 surface area. Thus the SFT25 is more intense by a factor of (2007/2521)(4.02/2.25)=1.42, which is a substantial advantage on the level of the emitter.
As a whole system, the C8’s reflector is well-made enough (i.e., free of surface irregularities) that the SFT40’s larger die offers no advantage in throw, or rather, that the SFT25 is not punished for having a smaller die that requires higher precision in the reflector to properly focus.
Why not get 2 or 3 complete lights with different emitters/drivers from Simon to start, then modify and build once you’ve compared them and decided what you want?
I’d go with:
XHP70.3 HI - high output, floody beam
SFT-40 intermediate option, good balance between throw and output
CULPM1 or something for pencil beam.
12-mode driver for all of them, if it’s available.
You could order some other emitters and drivers at the same time to mix n match. Once you’ve decided what else you want to try, put in a second order with Simon for the emitters/hosts/drivers you want.
519a is a fun emitter, output and tint is pretty good despite being high CRI, plus they’re easy to de-dome so you can compare dome/dedome easily.
You wrote: Why not get 2 or 3 complete lights with different emitters/drivers from Simon to start, then modify and build once you’ve compared them and decided what you want?
I thought the smaller die makes for better throwing, the bigger die puts more lumens into the flood portion of the beam. Is that all wrong? I got that idea by comparing the beams of the Giggles when it first was delivered to the buyers of start up of that design to the same host with xhp 70 put in by one of prominent contributors at blf. I don’t remember any other details, just what I saw in the video, and then i attempted some flashlighting theory that has stuck with me.
Your post seemed strongly connected to basic flashlight physics it is about time for me get right, entering this c8 project.
This answer is exactly what I needed for spelling out the components needed to make a C8.
I have two followup questions:
[Just found my answer] I was going to ask about C8 vs. C8+. I just looked up that topic. For me, C8+ will be better, because the shelf tends to soak up the heat better than the pill on the C8.
Ok, so once all the parts arrive at my house, is there a good place to find instructions on how to put all the pieces together? I am for sure going to need two kinds of assembly instructions
… First, I need to the basics of how to assemble a flashlight from these parts
… Second, I need a guide to the fine details and warnings to make the light built really right, to the point where a top expert coukd look at a flasglight, spot all the little things that indicate job well done.
Correct, the discussion here is the technical nuances about if the SFT makes up for it’s bigger size by having a substantially greater output. Bare in mind at the same drive current (=runtime), the small LED will throw further, the larger LED needs more power to throw the same distance.
This forum is good and YouTube. If you’ve host plus driver plus LED on MCPCB, It’s really a case of just soldering wires together. If you have pre-built lights, it’s obvious what goes where and you can just swap parts.
Two common issues:
LEDs have polarity, check the polarity with a DMM before wiring up the driver
Make sure the reflector is not shorting out the LED MCPCB when you assemble the light.
Experience.
The C8+ is of standard construction, doesn’t have Auxiliary LEDs on the MCPCB and is large enough to not be too fiddly, in the grand scheme of things, it’s not a difficult light to mod, so long as you can solder.
I have some broken lights I was going to fix after leaning from the build of these five. Now, i am thinking i would save a lot of time and risk of foul ups by ordering the C8+'s from BG, and working in the fixes sooner than later.
Don’t be seduced by the headline MAX LUMENS stated, anything that’s running (allegedly) 3500 lumens in a C8 sized light will get hot and step down quickly.
The A6 driver is also a FET driver so will dim as the battery dies (I think).
Simon (owner of Convoy and general lighting legend) has his we shop here: https://convoylight.com/
Forgot to add: in your opening post you ask for 5000K LEDs and high CRI. I suspect neither are 5000K and it’s even less likely they are high CRI.
CRI isnt always that important, if you want max output, for example, just go with the CCT you want (5000k, eg).
