My first build/mod - Advice and Recommendations

I didn’t read the fine print and purchased a Astrolux C8 shell thinking I was getting a complete light. Do you think I should source a driver and install it myself or start over and purchase a complete light? I have never modded a light but have general knowledge of electronics and can solder.
This light was purchased to mount on a scope mounted pic rail because of it’s long throw, 18650 batt and price.
Any advice/recommendations are much appreciated.

If you can solder and have basic electronics skills, you can do this!
You need the driver (/w spring), wires, the emitter, MCPCB, and the host should have the reflector, tail cap /w switch, and a battery.
Driver should come with firmware pre-flashed (that is how I have seen it so far, only self-built drivers should need flashing).

you need to decide whether it is easier to solder the emitter MCPCB first or the driver first, everyone will have a different opinion.

Do you have a multimeter? Would be useful to check for shorts before testing the light.

edit: I will let others pitch in whether a scope mounted light needs potting or not.

Yes I have a multimeter but I’m not familiar with potting.

You may not need to pot the driver, but I don’t know the longevity of a rifle mounted C8 though /w or without potting. maybe others can say a little about this.

forgot to mention that you may also need a plastic gasket between the reflector and the MCPCB to center the LED and prevent shorts. It may come with the light or it may not.
they look like this:

here a few videos on flashlights, there are more on youtube

Welcome to BLF ‘GunsAndGlass’ :sunglasses:
No need to delay getting hooked on modding, you will always get more enjoyment building it yourself, plus you will have a better light. :wink:

That’s my problem. I want to mod everything.

Awesome. I will watch.

What emitter/driver do you recommend (and where purchase)?

Since this is a first build, and I just did a first build not long ago, I’m going to recommend you do mostly what I did to start out.

Before actually ordering anything, you need to measure what diameter Emitter and Driver your host can take. Most lights have a removable pill by turning and unscrewing. Measure the diameter of the slots in metric. According to a listing I found for the Astrolux C8, it uses 20mm Emitter, but no information on the driver.

As for where to get the parts, Mountain Electronics is a very reliable US-based retailer offering very reasonable prices. If you’re not in the US, they do offer international shipping, but I’d look elsewhere.

For emitter, I recommend the Samsung LH351D 5000k for its high output for power, good tint, and good color accuracy.

For driver, I recommend getting a QLITE with default firmware. Just note, the QLITE is a 17mm driver. If your light needs 20mm driver, you should also get this adapter ring .

Later on if you want to really crank up the output you can look into a FET driver, but for now this will make your flashlight work.

You want multiple modes, or just 1-mode, on/off?

Especially with recoil jiggling the cell inside, it’s possible for it to switch modes when you don’t want it to, as if you half-pressed the switch. That’s why a lotta people are interested in simple stoopit drivers, no extra crap that can go wrong.

What do you want the light to do? Do you want it to throw light far? Do you want more flood, like lighting up a large area? How bright do you want it to be? Basics, the driver on the thorfire C8 takes a 17mm driver, and you need an led on a 20mm mcpcb or star. If you want a good all around set up, I’d hop on Aliexpress and hit up the Convoy store and get the 4-mode linear sst40 driver and a 5000k sst40 on a 20mm mcpcb. You’ll need to get a 9mm 5050 centering gasket, just ask Simon for one when you check out and he’ll throw one in. If you want a little more throw (light goes farther), get a Cree xp-l hi instead of the sst40. Ask for a 3535 gasket. The sst40 wil be brighter than the cree.

If I remember correctly, the driver is a A6 Samsung. I’m not familiar with what a FET driver is but I will look it up.
Btw I have a place outside of Petal and spend a lot of time there.

My priority in purchasing the Astrolux C8 was a “long throw” predator light.
A couple youtube videos informed my decision.

- YouTube Why I chose XPL-HI

Great. I think you’ll be happy with that setup. You can always swap in an Osram culpm1 for even more throw in the future.

Is this the Emitter you are recommending?

What is the difference between the Qlite and FET driver?


I recommend (for throw) this one: XP-L HI
For output and some throw (a little less than the xp-l): Sst40

I have several lights with the sst40 and really like it. Good efficiency and output. I like the xp-l also. For a driver, the Qlite is a linear driver running on current regulators that limit the current based on how many are on the driver. The FET driver, that uses a mosfet instead of the regulators (although some have a regulator and a fet) and are capable of much higher outputs since on higher modes there’s nothing except the resistance in the current path (flashlight body, wires, battery) to limit the current and you can overdrive the led or cause excessive heating and the output drops fast. So it depends on what you want to do with the light. For over 1000 lumens, you need a fet driver, for a hair over 1000 and less, the Qlite with 8-7135 works.

Excuse the uninformed question but what is the process for extending the time on hi before the auto stepdown?

I just read up on this and answered my own question.