First flashlight build

Hi I wanted to build one of my own flashlight. I already picked out the parts and was wondering if there could be any tweaking to it. Thank you

Convoy c8 host
XP-L HI with noctigon mcpcb
FET + 7135 driver

Do you have a soldering iron and or any experience with it?

C8 is a nice host. Xpl hi with c8 size reflector will give a nice throwy beam. So if you’re after that all will be good.

Yeah I had used soldering iron before.

Good choice. That’s almost exactly what my first build was.

Make sure you have some decent thermal grease to apply between the MCPCB and the C8’s shelf. AS5, MX4, etc.

Also, Convoy C8 hosts used to not come with the appropriate spacer for a 3535 LED like the XP-L HI. They came with only the 5050 (XM-L2 footprint) spacer. While the 5050 spacer would technically work, it’s more difficult to get the LED centered with it. Either make sure the host has the 3535 spacer or buy it separately. If you’re ordering from Mountain Electronics (suggested), just pick up one of these

Hi I have another question, I have seen people do spring bypass at the end cap. Do you know what is the purpose of it and should I do it on this build?

The purpose is to decrease resistance. Springs are commonly made of plated steel and are so-so conductors. And if you were to uncoil it, you would see it’s quite a long path so the resistance is greater.

A bypass literally provides a bypass for electrical conductivity without it needing to travel through the spring.

Will you visibly see a difference? Probably not. Does it increase risk? Certainly. If the bypass came loose, it could bypass the switch and turn your flashlight on. Or if you manage to create an accidental short when putting the driver and LED together, a bypass will be a very low resistance path for that short and you could risk damaging your battery or causing a fire, etc. Without a bypass, the spring would usually just collapse from the high heat and actually stop the flow of electricity.

A bypass isn’t a terrible idea, I just wouldn’t necessarily recommend it for your first built. Maybe if you’ve got it put together and you know everything is working fine, then maybe go back and add it.

Got it! Thank you!

Not sure where you are ordering parts but aliexpress has a official convoy store. The owner is active on the forum. You can get a small discount if you say you are a blf member. There is a stainless steel bezel for c8/c8+ which is nice and gives the light a nicer look imo.

Soldering inside the c8 head, to attach the wires to the led, can be difficult. Make sure you have tweezers or something to hold the wires down. Pre soldering the mcpcb really helps and makes it easier.

Do you have some knowledge about electronics?

Simple set up like that will work well, probably can buy a complete light cheaper than assembling one, it’s a good start if you do want to build something for your own satisfaction though.

When assembling, make sure the led wires don’t short on the reflector- usually a plastic gasket is provided.

Thanks I was wondering if I could make one with the more throw then. Do you recommend any led and driver for a max throw? I have seen people say xp-e2 dedome would give a better throw than xp-l hi.

Osram “Flat White 1mm²” is about the king of throw, but don’t use a FET or it’ll burn up. You’d want it regulated to 3-4 amps, 5 max. I’ve got one in a Emisar D1S running 5 amps (linear driver) and it’s awesome.

Dedomed XP-G2 is good, but not as great as it once was (Cree updated the LED a few years back and it’s just not quite the same).

Generally speaking… With the LED, it comes down to lumens and the size of the emitting surface. The smaller the die area (for the equal number of lumens) the higher the throw.

Flat white 1mm² led will give you the most throw with a c8 reflector. But centering it will be difficult and beam wont be very pretty up close. It will also heat up more quickly.

Thank you!

The convoy store on aliexpress has a 4 mode 5 amp driver which gives about 4.5 amp to the led netto. thats the max that you want to run this led. Also you need the correct size 3030 gasket which you can also get from the same store. Make sure you get good 18650 batteries like samsung 30Q.

Do you have a direct link to the 4mode 5 amp driver for the Flat white 1mm² led? Want to make sure it the correct one.
Thanks

#Aliexpress € 6,00 | 17 Mm Driver Voor SST40 ,4 Modi 0.1–3–30–100, max Huidige Output 5000mA, Temperatuur Bescherming Management Binnen

This is the link to the driver. If you look around the shop you can find gaskets etc. Not sure which c8 or c8+(new design same inside, but better looking imo) you are looking at but some have 7mm reflector hole and some have 9mm reflector hole. So you need to buy two kinds of gaskets or know in advance which reflector you are getting.

There is also the convoy m21a which is the c8+ with a larger 21700 battery, so more power and longer battey life but heavier. If you dont mind a slighly bigger heavier light i would buy that one.

I got a m21a with flat white 2mm led and 6amp driver that came with it. Still very throwy but around 1500 lumens and not 900 from flat white mm1

As others posts, the osram is good for throw but mind the maximum current.

More throw comes at a cost of fewer lumens, I think the 1mm flat white will do c.900 tops.

Also with the sst40 driver with the osram flat white 1mm does the tail cap need a spring bypass?

You wouldn’t notice any brightness changes, but it would be marginally more efficient with the reduced resistance.

You can buy a c8+ with sst40 and driver installed. You only need to swap the led and gasket. Make sure you have some thermal paste between mcpcb and flashlight body.