Small Sun – ZY-T08 Best of both worlds (beamshots uploaded)

This is my third mod of this budget flashlight and let me tell you, this host has to be every modders dream. Side by side batteries, right size, good heatsinking, robust and pretty well made. This one came from Fasttech but other parts were purchased from Kaidomain, my new favorite one stop shop.

Part list:

  1. ZY-T08 - $24.09 (Fasttech)
  2. 3x XPL-HI V2 4500K (20mm MCPCB) - $19.77 (Kaidomain)
  3. MTN FET driver - $15,00 (Mountain Electronics)
  4. 58mm AR coated lens - $3.46 (Kaidomain)
  5. 3x Trit Vials (1.5mm x 6mm) - $21.63 (Fasttech)
  6. 3x 25.5mm x 25mm reflectors - $9.39 (Kaidomain)
  7. 22mm Brass Pill - $3.49 (Kaidomain)
  8. Other supplies (copper, wires, springs, rubber boot, switch, sand paper…) - $15.00 (mostly local stores)

I also made around 30 different parts and managed to stuff them all in this little project of mine.

So it turned out to be a over hundred dollar flashlight, just in parts…
Was it worth it? I’ll let you be the judge…

1. Small Sun and most of the parts

2. Switch side pimping. Stock switch is to be replaced with reliable Omten.

3. Round ring extension on the tailcap is cut and base is sanded and polished.

4. Switch side parts are ready.

5. Copper plate soldered, spring bypasses done. There wont be any electrical resistance there.

6. Top side. One continues 18 AWG wire to conduct current to the body. Second continues wire goes from top of the spring directly to the switch.

7. Made a 5mm fiberglass plate. It is to be used as a reflector holder and a contact plate.

8. Three 25.5mm (width) x 25mm (depth) reflectors. It is going to be a tight fit.

9. Making holes for reflectors.

10. It came up nice.

11. Reflectors epoxied.

12. Top side. Touch of sand paper and some paint is all it needs for a perfect finish.

13. Pill parts. It is going to be assembled from three sections. These are parts for two of them.

14. Bottom part done (soldering).

15. Brazing the middle section. I’m going to use few aluminum parts mainly to save on the overall weight.

16. Cooking pot. Had to apply almost 400 C to melt brazing rods. It is a success.

17. Two sections of the pill almost done.

18. Top plate done, three part pill is at the finish line. Now it needs some minor tweaking to fit properly. I’ll come back to that.

19. Making the contact plate. Copper plate for battery contact, positive wires soldered trough the metal. On the other side (inside the flashlight head), brass pill is going to hold the driver and rest on a aluminum plate for better heatsinking.

20. Contact plate parts done.

21. Contact plate done.

22. A touch of arctic alumina epoxy to join the brass pill and aluminum plate is all there is left to do. So how do I connect the negative contact to driver with minimum electrical resistance? We’ll come back to that.

23. Pill parts done. Threaded, sanded to fit and polished.

24. Different angle.

25. Middle part bolted.

26. Top part bolted.

27. Pill finished. As you may have noticed, I had to made another top section. Brazing flat surfaces didn’t hold. It came apart during drilling.

28. Making custom centering rings. Had to sand them down (bottom 0.5mm, top 0.5mm) and reduce the width from 8mm to 6mm. Three XPL’s on 20mm MCPCB’s trimmed to fit are in the background.

29. Ground problem solved. 18 AWG wire brazed to the head of the flashlight. Other end of the wire is going to be soldered to the drivers pill.

30. Assembly day. Ain’t that a pretty sight. There’s still lot of work ahead.

31. Cut to fit MCPCB’s arranged. Reflectors are going to press them down. No gluing needed there. Tailor made centering rings are going to hold LED’s in their place.

32. Pill epoxied with Arctic Alumina, all contacts soldered. Pill holder is going to be lightly glued with plain silicone.

33. Finished ZY-T08 Triple. I even managed to polish the metal inside the cooling fins using a rope. Got a few blisters on my hands doing this but it was worth it.

34. You gotta love this sight. Three warm XPL-HI’s inside 25mm x 25mm OP reflectors surrounded with trit vials.

35. Please ignore scratched lens. I ruined them during the build process, new lens are on the way from Kaidomain. Pay attention to the blue circles around the reflectors. I don’t know how that happened but it sure looks beautiful and it doesn’t affect the beam at all.

36. Green trits in half-light.

I’ll make current measurements and post them later. I will also try to make beam shots for you to see what a beautiful beam this flashlight produces. There is a distinguished hot spot and a smooth transition to spill. So, is this thrower or flooder? Let me say, best of both worlds.

Did you like my ZY-T08 Triple? Please comment.


Great job on the light! One of these days I have to polish out my lights to a mirror finish like you have.

I think anyone whod like to copy this build can find ready plastic holder for 3 or 4 20mm optics in 50mm size.
You are right, this host is one of the best both in heat transfert to outside surfaces and convection to the air.
P.S. Please PM me. Id like to giveaway you one interesting part.

Pure porn

Wow very nice and impressive!

Nice mod. I’m guessing the circles are reflected light from the inside of the exterior lens/air interface illuminating the epoxy around the reflector(if that makes any sense).

You did an awesome job ! :+1:

Culla, you’ve done a fantastic job.

As usual, this mod is top notch !
I’m truly jealous of your skills/patience/ideas !
Good job !

Awesome mods. Thanks for sharing :beer:

Couldn’t agree more with everyone’s comments. Amazing effort and skills. Thanks for posting it up.

Outstanding work again!
You chose one of the ugliest hosts around (in my opinion) but that does not matter, after you’re done it is a wow light!! :open_mouth:

Another 5* mod from you Cula ! :beer:

Thanks for sharing…

Wow, nice mod, great job :+1:

Avesome job!!!
Bravo!!! :+1:

Impressive! Thank you for taking the time to take pics at each step of the process.

  1. Is there any “springiness” or compression room remaining in the spring bypass setup? In other words, any wiggle-room for slightly different lengths of batteries? Maybe this doesn’t matter since protected cells will never be used here :wink:
  2. What is your preferred method of sanding and polishing the exterior? Great idea using rope for the cooling fins!

You could be a jeweler, :heart_eyes:

Fantastic job! I only wish I had the knowledge to do something similar myself… One day I’ll try to mod something. I think I’ll start with a S2+ triple.


Thank you guys for your comments :beer: .

You are indeed right. It is a reflection from AR lenses.


1) Barely, don’t have any protected ones to try. I can’t be sure.

2) I used something like this mounted on my bench drill ( and a lot of elbow grease :slight_smile: . This kit can be bought in almost every hardware store.